1 /*
2 * Copyright (c) 1994, 2018, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25 package java.lang;
26
27 import java.io.BufferedInputStream;
28 import java.io.BufferedOutputStream;
29 import java.io.Console;
30 import java.io.FileDescriptor;
31 import java.io.FileInputStream;
32 import java.io.FileOutputStream;
33 import java.io.IOException;
34 import java.io.InputStream;
35 import java.io.PrintStream;
36 import java.io.UnsupportedEncodingException;
37 import java.lang.annotation.Annotation;
38 import java.lang.module.ModuleDescriptor;
39 import java.lang.reflect.Constructor;
40 import java.lang.reflect.Executable;
41 import java.lang.reflect.Method;
42 import java.lang.reflect.Modifier;
43 import java.net.URI;
44 import java.security.AccessControlContext;
45 import java.security.ProtectionDomain;
46 import java.security.AccessController;
47 import java.security.PrivilegedAction;
48 import java.nio.channels.Channel;
49 import java.nio.channels.spi.SelectorProvider;
50 import java.util.Iterator;
51 import java.util.List;
52 import java.util.Map;
53 import java.util.Objects;
54 import java.util.Properties;
55 import java.util.PropertyPermission;
56 import java.util.ResourceBundle;
57 import java.util.function.Supplier;
58 import java.util.concurrent.ConcurrentHashMap;
59 import java.util.stream.Stream;
60
61 import jdk.internal.module.ModuleBootstrap;
62 import jdk.internal.module.ServicesCatalog;
63 import jdk.internal.reflect.CallerSensitive;
64 import jdk.internal.reflect.Reflection;
65 import jdk.internal.HotSpotIntrinsicCandidate;
66 import jdk.internal.misc.JavaLangAccess;
67 import jdk.internal.misc.SharedSecrets;
68 import jdk.internal.misc.VM;
69 import jdk.internal.logger.LoggerFinderLoader;
70 import jdk.internal.logger.LazyLoggers;
71 import jdk.internal.logger.LocalizedLoggerWrapper;
72 import sun.reflect.annotation.AnnotationType;
73 import sun.nio.ch.Interruptible;
74 import sun.security.util.SecurityConstants;
75
76 /**
77 * The {@code System} class contains several useful class fields
78 * and methods. It cannot be instantiated.
79 *
80 * Among the facilities provided by the {@code System} class
81 * are standard input, standard output, and error output streams;
82 * access to externally defined properties and environment
83 * variables; a means of loading files and libraries; and a utility
84 * method for quickly copying a portion of an array.
85 *
86 * @since 1.0
87 */
88 public final class System {
89 /* Register the natives via the static initializer.
90 *
91 * VM will invoke the initializeSystemClass method to complete
92 * the initialization for this class separated from clinit.
93 * Note that to use properties set by the VM, see the constraints
94 * described in the initializeSystemClass method.
95 */
96 private static native void registerNatives();
97 static {
98 registerNatives();
99 }
100
101 /** Don't let anyone instantiate this class */
102 private System() {
103 }
104
105 /**
106 * The "standard" input stream. This stream is already
107 * open and ready to supply input data. Typically this stream
108 * corresponds to keyboard input or another input source specified by
109 * the host environment or user.
110 */
111 public static final InputStream in = null;
112
113 /**
114 * The "standard" output stream. This stream is already
115 * open and ready to accept output data. Typically this stream
116 * corresponds to display output or another output destination
117 * specified by the host environment or user.
118 * <p>
119 * For simple stand-alone Java applications, a typical way to write
120 * a line of output data is:
121 * <blockquote><pre>
122 * System.out.println(data)
123 * </pre></blockquote>
124 * <p>
125 * See the {@code println} methods in class {@code PrintStream}.
126 *
127 * @see java.io.PrintStream#println()
128 * @see java.io.PrintStream#println(boolean)
129 * @see java.io.PrintStream#println(char)
130 * @see java.io.PrintStream#println(char[])
131 * @see java.io.PrintStream#println(double)
132 * @see java.io.PrintStream#println(float)
133 * @see java.io.PrintStream#println(int)
134 * @see java.io.PrintStream#println(long)
135 * @see java.io.PrintStream#println(java.lang.Object)
136 * @see java.io.PrintStream#println(java.lang.String)
137 */
138 public static final PrintStream out = null;
139
140 /**
141 * The "standard" error output stream. This stream is already
142 * open and ready to accept output data.
143 * <p>
144 * Typically this stream corresponds to display output or another
145 * output destination specified by the host environment or user. By
146 * convention, this output stream is used to display error messages
147 * or other information that should come to the immediate attention
148 * of a user even if the principal output stream, the value of the
149 * variable {@code out}, has been redirected to a file or other
150 * destination that is typically not continuously monitored.
151 */
152 public static final PrintStream err = null;
153
154 /* The security manager for the system.
155 */
156 private static volatile SecurityManager security;
157
158 /**
159 * Reassigns the "standard" input stream.
160 *
161 * First, if there is a security manager, its {@code checkPermission}
162 * method is called with a {@code RuntimePermission("setIO")} permission
163 * to see if it's ok to reassign the "standard" input stream.
164 *
165 * @param in the new standard input stream.
166 *
167 * @throws SecurityException
168 * if a security manager exists and its
169 * {@code checkPermission} method doesn't allow
170 * reassigning of the standard input stream.
171 *
172 * @see SecurityManager#checkPermission
173 * @see java.lang.RuntimePermission
174 *
175 * @since 1.1
176 */
177 public static void setIn(InputStream in) {
178 checkIO();
179 setIn0(in);
180 }
181
182 /**
183 * Reassigns the "standard" output stream.
184 *
185 * First, if there is a security manager, its {@code checkPermission}
186 * method is called with a {@code RuntimePermission("setIO")} permission
187 * to see if it's ok to reassign the "standard" output stream.
188 *
189 * @param out the new standard output stream
190 *
191 * @throws SecurityException
192 * if a security manager exists and its
193 * {@code checkPermission} method doesn't allow
194 * reassigning of the standard output stream.
195 *
196 * @see SecurityManager#checkPermission
197 * @see java.lang.RuntimePermission
198 *
199 * @since 1.1
200 */
201 public static void setOut(PrintStream out) {
202 checkIO();
203 setOut0(out);
204 }
205
206 /**
207 * Reassigns the "standard" error output stream.
208 *
209 * First, if there is a security manager, its {@code checkPermission}
210 * method is called with a {@code RuntimePermission("setIO")} permission
211 * to see if it's ok to reassign the "standard" error output stream.
212 *
213 * @param err the new standard error output stream.
214 *
215 * @throws SecurityException
216 * if a security manager exists and its
217 * {@code checkPermission} method doesn't allow
218 * reassigning of the standard error output stream.
219 *
220 * @see SecurityManager#checkPermission
221 * @see java.lang.RuntimePermission
222 *
223 * @since 1.1
224 */
225 public static void setErr(PrintStream err) {
226 checkIO();
227 setErr0(err);
228 }
229
230 private static volatile Console cons;
231 /**
232 * Returns the unique {@link java.io.Console Console} object associated
233 * with the current Java virtual machine, if any.
234 *
235 * @return The system console, if any, otherwise {@code null}.
236 *
237 * @since 1.6
238 */
239 public static Console console() {
240 Console c;
241 if ((c = cons) == null) {
242 synchronized (System.class) {
243 if ((c = cons) == null) {
244 cons = c = SharedSecrets.getJavaIOAccess().console();
245 }
246 }
247 }
248 return c;
249 }
250
251 /**
252 * Returns the channel inherited from the entity that created this
253 * Java virtual machine.
254 *
255 * This method returns the channel obtained by invoking the
256 * {@link java.nio.channels.spi.SelectorProvider#inheritedChannel
257 * inheritedChannel} method of the system-wide default
258 * {@link java.nio.channels.spi.SelectorProvider} object.
259 *
260 * <p> In addition to the network-oriented channels described in
261 * {@link java.nio.channels.spi.SelectorProvider#inheritedChannel
262 * inheritedChannel}, this method may return other kinds of
263 * channels in the future.
264 *
265 * @return The inherited channel, if any, otherwise {@code null}.
266 *
267 * @throws IOException
268 * If an I/O error occurs
269 *
270 * @throws SecurityException
271 * If a security manager is present and it does not
272 * permit access to the channel.
273 *
274 * @since 1.5
275 */
276 public static Channel inheritedChannel() throws IOException {
277 return SelectorProvider.provider().inheritedChannel();
278 }
279
280 private static void checkIO() {
281 SecurityManager sm = getSecurityManager();
282 if (sm != null) {
283 sm.checkPermission(new RuntimePermission("setIO"));
284 }
285 }
286
287 private static native void setIn0(InputStream in);
288 private static native void setOut0(PrintStream out);
289 private static native void setErr0(PrintStream err);
290
291 /**
292 * Sets the System security.
293 *
294 * If there is a security manager already installed, this method first
295 * calls the security manager's {@code checkPermission} method
296 * with a {@code RuntimePermission("setSecurityManager")}
297 * permission to ensure it's ok to replace the existing
298 * security manager.
299 * This may result in throwing a {@code SecurityException}.
300 *
301 * <p> Otherwise, the argument is established as the current
302 * security manager. If the argument is {@code null} and no
303 * security manager has been established, then no action is taken and
304 * the method simply returns.
305 *
306 * @param s the security manager.
307 * @throws SecurityException if the security manager has already
308 * been set and its {@code checkPermission} method
309 * doesn't allow it to be replaced.
310 * @see #getSecurityManager
311 * @see SecurityManager#checkPermission
312 * @see java.lang.RuntimePermission
313 */
314 public static void setSecurityManager(final SecurityManager s) {
315 if (security == null) {
316 // ensure image reader is initialized
317 Object.class.getResource("java/lang/ANY");
318 }
319 if (s != null) {
320 try {
321 s.checkPackageAccess("java.lang");
322 } catch (Exception e) {
323 // no-op
324 }
325 }
326 setSecurityManager0(s);
327 }
328
329 private static synchronized
330 void setSecurityManager0(final SecurityManager s) {
331 SecurityManager sm = getSecurityManager();
332 if (sm != null) {
333 // ask the currently installed security manager if we
334 // can replace it.
335 sm.checkPermission(new RuntimePermission
336 ("setSecurityManager"));
337 }
338
339 if ((s != null) && (s.getClass().getClassLoader() != null)) {
340 // New security manager class is not on bootstrap classpath.
341 // Cause policy to get initialized before we install the new
342 // security manager, in order to prevent infinite loops when
343 // trying to initialize the policy (which usually involves
344 // accessing some security and/or system properties, which in turn
345 // calls the installed security manager's checkPermission method
346 // which will loop infinitely if there is a non-system class
347 // (in this case: the new security manager class) on the stack).
348 AccessController.doPrivileged(new PrivilegedAction<>() {
349 public Object run() {
350 s.getClass().getProtectionDomain().implies
351 (SecurityConstants.ALL_PERMISSION);
352 return null;
353 }
354 });
355 }
356
357 security = s;
358 }
359
360 /**
361 * Gets the system security interface.
362 *
363 * @return if a security manager has already been established for the
364 * current application, then that security manager is returned;
365 * otherwise, {@code null} is returned.
366 * @see #setSecurityManager
367 */
368 public static SecurityManager getSecurityManager() {
369 return security;
370 }
371
372 /**
373 * Returns the current time in milliseconds. Note that
374 * while the unit of time of the return value is a millisecond,
375 * the granularity of the value depends on the underlying
376 * operating system and may be larger. For example, many
377 * operating systems measure time in units of tens of
378 * milliseconds.
379 *
380 * <p> See the description of the class {@code Date} for
381 * a discussion of slight discrepancies that may arise between
382 * "computer time" and coordinated universal time (UTC).
383 *
384 * @return the difference, measured in milliseconds, between
385 * the current time and midnight, January 1, 1970 UTC.
386 * @see java.util.Date
387 */
388 @HotSpotIntrinsicCandidate
389 public static native long currentTimeMillis();
390
391 /**
392 * Returns the current value of the running Java Virtual Machine's
393 * high-resolution time source, in nanoseconds.
394 *
395 * This method can only be used to measure elapsed time and is
396 * not related to any other notion of system or wall-clock time.
397 * The value returned represents nanoseconds since some fixed but
398 * arbitrary <i>origin</i> time (perhaps in the future, so values
399 * may be negative). The same origin is used by all invocations of
400 * this method in an instance of a Java virtual machine; other
401 * virtual machine instances are likely to use a different origin.
402 *
403 * <p>This method provides nanosecond precision, but not necessarily
404 * nanosecond resolution (that is, how frequently the value changes)
405 * - no guarantees are made except that the resolution is at least as
406 * good as that of {@link #currentTimeMillis()}.
407 *
408 * <p>Differences in successive calls that span greater than
409 * approximately 292 years (2<sup>63</sup> nanoseconds) will not
410 * correctly compute elapsed time due to numerical overflow.
411 *
412 * <p>The values returned by this method become meaningful only when
413 * the difference between two such values, obtained within the same
414 * instance of a Java virtual machine, is computed.
415 *
416 * <p>For example, to measure how long some code takes to execute:
417 * <pre> {@code
418 * long startTime = System.nanoTime();
419 * // ... the code being measured ...
420 * long elapsedNanos = System.nanoTime() - startTime;}</pre>
421 *
422 * <p>To compare elapsed time against a timeout, use <pre> {@code
423 * if (System.nanoTime() - startTime >= timeoutNanos) ...}</pre>
424 * instead of <pre> {@code
425 * if (System.nanoTime() >= startTime + timeoutNanos) ...}</pre>
426 * because of the possibility of numerical overflow.
427 *
428 * @return the current value of the running Java Virtual Machine's
429 * high-resolution time source, in nanoseconds
430 * @since 1.5
431 */
432 @HotSpotIntrinsicCandidate
433 public static native long nanoTime();
434
435 /**
436 * Copies an array from the specified source array, beginning at the
437 * specified position, to the specified position of the destination array.
438 * A subsequence of array components are copied from the source
439 * array referenced by {@code src} to the destination array
440 * referenced by {@code dest}. The number of components copied is
441 * equal to the {@code length} argument. The components at
442 * positions {@code srcPos} through
443 * {@code srcPos+length-1} in the source array are copied into
444 * positions {@code destPos} through
445 * {@code destPos+length-1}, respectively, of the destination
446 * array.
447 * <p>
448 * If the {@code src} and {@code dest} arguments refer to the
449 * same array object, then the copying is performed as if the
450 * components at positions {@code srcPos} through
451 * {@code srcPos+length-1} were first copied to a temporary
452 * array with {@code length} components and then the contents of
453 * the temporary array were copied into positions
454 * {@code destPos} through {@code destPos+length-1} of the
455 * destination array.
456 * <p>
457 * If {@code dest} is {@code null}, then a
458 * {@code NullPointerException} is thrown.
459 * <p>
460 * If {@code src} is {@code null}, then a
461 * {@code NullPointerException} is thrown and the destination
462 * array is not modified.
463 * <p>
464 * Otherwise, if any of the following is true, an
465 * {@code ArrayStoreException} is thrown and the destination is
466 * not modified:
467 * <ul>
468 * <li>The {@code src} argument refers to an object that is not an
469 * array.
470 * <li>The {@code dest} argument refers to an object that is not an
471 * array.
472 * <li>The {@code src} argument and {@code dest} argument refer
473 * to arrays whose component types are different primitive types.
474 * <li>The {@code src} argument refers to an array with a primitive
475 * component type and the {@code dest} argument refers to an array
476 * with a reference component type.
477 * <li>The {@code src} argument refers to an array with a reference
478 * component type and the {@code dest} argument refers to an array
479 * with a primitive component type.
480 * </ul>
481 * <p>
482 * Otherwise, if any of the following is true, an
483 * {@code IndexOutOfBoundsException} is
484 * thrown and the destination is not modified:
485 * <ul>
486 * <li>The {@code srcPos} argument is negative.
487 * <li>The {@code destPos} argument is negative.
488 * <li>The {@code length} argument is negative.
489 * <li>{@code srcPos+length} is greater than
490 * {@code src.length}, the length of the source array.
491 * <li>{@code destPos+length} is greater than
492 * {@code dest.length}, the length of the destination array.
493 * </ul>
494 * <p>
495 * Otherwise, if any actual component of the source array from
496 * position {@code srcPos} through
497 * {@code srcPos+length-1} cannot be converted to the component
498 * type of the destination array by assignment conversion, an
499 * {@code ArrayStoreException} is thrown. In this case, let
500 * <b><i>k</i></b> be the smallest nonnegative integer less than
501 * length such that {@code src[srcPos+}<i>k</i>{@code ]}
502 * cannot be converted to the component type of the destination
503 * array; when the exception is thrown, source array components from
504 * positions {@code srcPos} through
505 * {@code srcPos+}<i>k</i>{@code -1}
506 * will already have been copied to destination array positions
507 * {@code destPos} through
508 * {@code destPos+}<i>k</I>{@code -1} and no other
509 * positions of the destination array will have been modified.
510 * (Because of the restrictions already itemized, this
511 * paragraph effectively applies only to the situation where both
512 * arrays have component types that are reference types.)
513 *
514 * @param src the source array.
515 * @param srcPos starting position in the source array.
516 * @param dest the destination array.
517 * @param destPos starting position in the destination data.
518 * @param length the number of array elements to be copied.
519 * @throws IndexOutOfBoundsException if copying would cause
520 * access of data outside array bounds.
521 * @throws ArrayStoreException if an element in the {@code src}
522 * array could not be stored into the {@code dest} array
523 * because of a type mismatch.
524 * @throws NullPointerException if either {@code src} or
525 * {@code dest} is {@code null}.
526 */
527 @HotSpotIntrinsicCandidate
528 public static native void arraycopy(Object src, int srcPos,
529 Object dest, int destPos,
530 int length);
531
532 /**
533 * Returns the same hash code for the given object as
534 * would be returned by the default method hashCode(),
535 * whether or not the given object's class overrides
536 * hashCode().
537 * The hash code for the null reference is zero.
538 *
539 * @param x object for which the hashCode is to be calculated
540 * @return the hashCode
541 * @since 1.1
542 * @see Object#hashCode
543 * @see java.util.Objects#hashCode(Object)
544 */
545 @HotSpotIntrinsicCandidate
546 public static native int identityHashCode(Object x);
547
548 /**
549 * System properties. The following properties are guaranteed to be defined:
550 * <dl>
551 * <dt>java.version <dd>Java version number
552 * <dt>java.version.date <dd>Java version date
553 * <dt>java.vendor <dd>Java vendor specific string
554 * <dt>java.vendor.url <dd>Java vendor URL
555 * <dt>java.vendor.version <dd>Java vendor version
556 * <dt>java.home <dd>Java installation directory
557 * <dt>java.class.version <dd>Java class version number
558 * <dt>java.class.path <dd>Java classpath
559 * <dt>os.name <dd>Operating System Name
560 * <dt>os.arch <dd>Operating System Architecture
561 * <dt>os.version <dd>Operating System Version
562 * <dt>file.separator <dd>File separator ("/" on Unix)
563 * <dt>path.separator <dd>Path separator (":" on Unix)
564 * <dt>line.separator <dd>Line separator ("\n" on Unix)
565 * <dt>user.name <dd>User account name
566 * <dt>user.home <dd>User home directory
567 * <dt>user.dir <dd>User's current working directory
568 * </dl>
569 */
570
571 private static Properties props;
572 private static native Properties initProperties(Properties props);
573
574 /**
575 * Determines the current system properties.
576 *
577 * First, if there is a security manager, its
578 * {@code checkPropertiesAccess} method is called with no
579 * arguments. This may result in a security exception.
580 * <p>
581 * The current set of system properties for use by the
582 * {@link #getProperty(String)} method is returned as a
583 * {@code Properties} object. If there is no current set of
584 * system properties, a set of system properties is first created and
585 * initialized. This set of system properties always includes values
586 * for the following keys:
587 * <table class="striped" style="text-align:left">
588 * <caption style="display:none">Shows property keys and associated values</caption>
589 * <thead>
590 * <tr><th scope="col">Key</th>
591 * <th scope="col">Description of Associated Value</th></tr>
592 * </thead>
593 * <tbody>
594 * <tr><th scope="row">{@code java.version}</th>
595 * <td>Java Runtime Environment version, which may be interpreted
596 * as a {@link Runtime.Version}</td></tr>
597 * <tr><th scope="row">{@code java.version.date}</th>
598 * <td>Java Runtime Environment version date, in ISO-8601 YYYY-MM-DD
599 * format, which may be interpreted as a {@link
600 * java.time.LocalDate}</td></tr>
601 * <tr><th scope="row">{@code java.vendor}</th>
602 * <td>Java Runtime Environment vendor</td></tr>
603 * <tr><th scope="row">{@code java.vendor.url}</th>
604 * <td>Java vendor URL</td></tr>
605 * <tr><th scope="row">{@code java.vendor.version}</th>
606 * <td>Java vendor version</td></tr>
607 * <tr><th scope="row">{@code java.home}</th>
608 * <td>Java installation directory</td></tr>
609 * <tr><th scope="row">{@code java.vm.specification.version}</th>
610 * <td>Java Virtual Machine specification version which may be
611 * interpreted as a {@link Runtime.Version}</td></tr>
612 * <tr><th scope="row">{@code java.vm.specification.vendor}</th>
613 * <td>Java Virtual Machine specification vendor</td></tr>
614 * <tr><th scope="row">{@code java.vm.specification.name}</th>
615 * <td>Java Virtual Machine specification name</td></tr>
616 * <tr><th scope="row">{@code java.vm.version}</th>
617 * <td>Java Virtual Machine implementation version which may be
618 * interpreted as a {@link Runtime.Version}</td></tr>
619 * <tr><th scope="row">{@code java.vm.vendor}</th>
620 * <td>Java Virtual Machine implementation vendor</td></tr>
621 * <tr><th scope="row">{@code java.vm.name}</th>
622 * <td>Java Virtual Machine implementation name</td></tr>
623 * <tr><th scope="row">{@code java.specification.version}</th>
624 * <td>Java Runtime Environment specification version which may be
625 * interpreted as a {@link Runtime.Version}</td></tr>
626 * <tr><th scope="row">{@code java.specification.vendor}</th>
627 * <td>Java Runtime Environment specification vendor</td></tr>
628 * <tr><th scope="row">{@code java.specification.name}</th>
629 * <td>Java Runtime Environment specification name</td></tr>
630 * <tr><th scope="row">{@code java.class.version}</th>
631 * <td>Java class format version number</td></tr>
632 * <tr><th scope="row">{@code java.class.path}</th>
633 * <td>Java class path (refer to
634 * {@link ClassLoader#getSystemClassLoader()} for details)</td></tr>
635 * <tr><th scope="row">{@code java.library.path}</th>
636 * <td>List of paths to search when loading libraries</td></tr>
637 * <tr><th scope="row">{@code java.io.tmpdir}</th>
638 * <td>Default temp file path</td></tr>
639 * <tr><th scope="row">{@code java.compiler}</th>
640 * <td>Name of JIT compiler to use</td></tr>
641 * <tr><th scope="row">{@code os.name}</th>
642 * <td>Operating system name</td></tr>
643 * <tr><th scope="row">{@code os.arch}</th>
644 * <td>Operating system architecture</td></tr>
645 * <tr><th scope="row">{@code os.version}</th>
646 * <td>Operating system version</td></tr>
647 * <tr><th scope="row">{@code file.separator}</th>
648 * <td>File separator ("/" on UNIX)</td></tr>
649 * <tr><th scope="row">{@code path.separator}</th>
650 * <td>Path separator (":" on UNIX)</td></tr>
651 * <tr><th scope="row">{@code line.separator}</th>
652 * <td>Line separator ("\n" on UNIX)</td></tr>
653 * <tr><th scope="row">{@code user.name}</th>
654 * <td>User's account name</td></tr>
655 * <tr><th scope="row">{@code user.home}</th>
656 * <td>User's home directory</td></tr>
657 * <tr><th scope="row">{@code user.dir}</th>
658 * <td>User's current working directory</td></tr>
659 * </tbody>
660 * </table>
661 * <p>
662 * Multiple paths in a system property value are separated by the path
663 * separator character of the platform.
664 * <p>
665 * Note that even if the security manager does not permit the
666 * {@code getProperties} operation, it may choose to permit the
667 * {@link #getProperty(String)} operation.
668 *
669 * @implNote In addition to the standard system properties, the system
670 * properties may include the following keys:
671 * <table class="striped">
672 * <caption style="display:none">Shows property keys and associated values</caption>
673 * <thead>
674 * <tr><th scope="col">Key</th>
675 * <th scope="col">Description of Associated Value</th></tr>
676 * </thead>
677 * <tbody>
678 * <tr><th scope="row">{@code jdk.module.path}</th>
679 * <td>The application module path</td></tr>
680 * <tr><th scope="row">{@code jdk.module.upgrade.path}</th>
681 * <td>The upgrade module path</td></tr>
682 * <tr><th scope="row">{@code jdk.module.main}</th>
683 * <td>The module name of the initial/main module</td></tr>
684 * <tr><th scope="row">{@code jdk.module.main.class}</th>
685 * <td>The main class name of the initial module</td></tr>
686 * </tbody>
687 * </table>
688 *
689 * @return the system properties
690 * @throws SecurityException if a security manager exists and its
691 * {@code checkPropertiesAccess} method doesn't allow access
692 * to the system properties.
693 * @see #setProperties
694 * @see java.lang.SecurityException
695 * @see java.lang.SecurityManager#checkPropertiesAccess()
696 * @see java.util.Properties
697 */
698 public static Properties getProperties() {
699 SecurityManager sm = getSecurityManager();
700 if (sm != null) {
701 sm.checkPropertiesAccess();
702 }
703
704 return props;
705 }
706
707 /**
708 * Returns the system-dependent line separator string. It always
709 * returns the same value - the initial value of the {@linkplain
710 * #getProperty(String) system property} {@code line.separator}.
711 *
712 * <p>On UNIX systems, it returns {@code "\n"}; on Microsoft
713 * Windows systems it returns {@code "\r\n"}.
714 *
715 * @return the system-dependent line separator string
716 * @since 1.7
717 */
718 public static String lineSeparator() {
719 return lineSeparator;
720 }
721
722 private static String lineSeparator;
723
724 /**
725 * Sets the system properties to the {@code Properties} argument.
726 *
727 * First, if there is a security manager, its
728 * {@code checkPropertiesAccess} method is called with no
729 * arguments. This may result in a security exception.
730 * <p>
731 * The argument becomes the current set of system properties for use
732 * by the {@link #getProperty(String)} method. If the argument is
733 * {@code null}, then the current set of system properties is
734 * forgotten.
735 *
736 * @param props the new system properties.
737 * @throws SecurityException if a security manager exists and its
738 * {@code checkPropertiesAccess} method doesn't allow access
739 * to the system properties.
740 * @see #getProperties
741 * @see java.util.Properties
742 * @see java.lang.SecurityException
743 * @see java.lang.SecurityManager#checkPropertiesAccess()
744 */
745 public static void setProperties(Properties props) {
746 SecurityManager sm = getSecurityManager();
747 if (sm != null) {
748 sm.checkPropertiesAccess();
749 }
750 if (props == null) {
751 props = new Properties();
752 initProperties(props);
753 }
754 System.props = props;
755 }
756
757 /**
758 * Gets the system property indicated by the specified key.
759 *
760 * First, if there is a security manager, its
761 * {@code checkPropertyAccess} method is called with the key as
762 * its argument. This may result in a SecurityException.
763 * <p>
764 * If there is no current set of system properties, a set of system
765 * properties is first created and initialized in the same manner as
766 * for the {@code getProperties} method.
767 *
768 * @param key the name of the system property.
769 * @return the string value of the system property,
770 * or {@code null} if there is no property with that key.
771 *
772 * @throws SecurityException if a security manager exists and its
773 * {@code checkPropertyAccess} method doesn't allow
774 * access to the specified system property.
775 * @throws NullPointerException if {@code key} is {@code null}.
776 * @throws IllegalArgumentException if {@code key} is empty.
777 * @see #setProperty
778 * @see java.lang.SecurityException
779 * @see java.lang.SecurityManager#checkPropertyAccess(java.lang.String)
780 * @see java.lang.System#getProperties()
781 */
782 public static String getProperty(String key) {
783 checkKey(key);
784 SecurityManager sm = getSecurityManager();
785 if (sm != null) {
786 sm.checkPropertyAccess(key);
787 }
788
789 return props.getProperty(key);
790 }
791
792 /**
793 * Gets the system property indicated by the specified key.
794 *
795 * First, if there is a security manager, its
796 * {@code checkPropertyAccess} method is called with the
797 * {@code key} as its argument.
798 * <p>
799 * If there is no current set of system properties, a set of system
800 * properties is first created and initialized in the same manner as
801 * for the {@code getProperties} method.
802 *
803 * @param key the name of the system property.
804 * @param def a default value.
805 * @return the string value of the system property,
806 * or the default value if there is no property with that key.
807 *
808 * @throws SecurityException if a security manager exists and its
809 * {@code checkPropertyAccess} method doesn't allow
810 * access to the specified system property.
811 * @throws NullPointerException if {@code key} is {@code null}.
812 * @throws IllegalArgumentException if {@code key} is empty.
813 * @see #setProperty
814 * @see java.lang.SecurityManager#checkPropertyAccess(java.lang.String)
815 * @see java.lang.System#getProperties()
816 */
817 public static String getProperty(String key, String def) {
818 checkKey(key);
819 SecurityManager sm = getSecurityManager();
820 if (sm != null) {
821 sm.checkPropertyAccess(key);
822 }
823
824 return props.getProperty(key, def);
825 }
826
827 /**
828 * Sets the system property indicated by the specified key.
829 *
830 * First, if a security manager exists, its
831 * {@code SecurityManager.checkPermission} method
832 * is called with a {@code PropertyPermission(key, "write")}
833 * permission. This may result in a SecurityException being thrown.
834 * If no exception is thrown, the specified property is set to the given
835 * value.
836 *
837 * @param key the name of the system property.
838 * @param value the value of the system property.
839 * @return the previous value of the system property,
840 * or {@code null} if it did not have one.
841 *
842 * @throws SecurityException if a security manager exists and its
843 * {@code checkPermission} method doesn't allow
844 * setting of the specified property.
845 * @throws NullPointerException if {@code key} or
846 * {@code value} is {@code null}.
847 * @throws IllegalArgumentException if {@code key} is empty.
848 * @see #getProperty
849 * @see java.lang.System#getProperty(java.lang.String)
850 * @see java.lang.System#getProperty(java.lang.String, java.lang.String)
851 * @see java.util.PropertyPermission
852 * @see SecurityManager#checkPermission
853 * @since 1.2
854 */
855 public static String setProperty(String key, String value) {
856 checkKey(key);
857 SecurityManager sm = getSecurityManager();
858 if (sm != null) {
859 sm.checkPermission(new PropertyPermission(key,
860 SecurityConstants.PROPERTY_WRITE_ACTION));
861 }
862
863 return (String) props.setProperty(key, value);
864 }
865
866 /**
867 * Removes the system property indicated by the specified key.
868 *
869 * First, if a security manager exists, its
870 * {@code SecurityManager.checkPermission} method
871 * is called with a {@code PropertyPermission(key, "write")}
872 * permission. This may result in a SecurityException being thrown.
873 * If no exception is thrown, the specified property is removed.
874 *
875 * @param key the name of the system property to be removed.
876 * @return the previous string value of the system property,
877 * or {@code null} if there was no property with that key.
878 *
879 * @throws SecurityException if a security manager exists and its
880 * {@code checkPropertyAccess} method doesn't allow
881 * access to the specified system property.
882 * @throws NullPointerException if {@code key} is {@code null}.
883 * @throws IllegalArgumentException if {@code key} is empty.
884 * @see #getProperty
885 * @see #setProperty
886 * @see java.util.Properties
887 * @see java.lang.SecurityException
888 * @see java.lang.SecurityManager#checkPropertiesAccess()
889 * @since 1.5
890 */
891 public static String clearProperty(String key) {
892 checkKey(key);
893 SecurityManager sm = getSecurityManager();
894 if (sm != null) {
895 sm.checkPermission(new PropertyPermission(key, "write"));
896 }
897
898 return (String) props.remove(key);
899 }
900
901 private static void checkKey(String key) {
902 if (key == null) {
903 throw new NullPointerException("key can't be null");
904 }
905 if (key.equals("")) {
906 throw new IllegalArgumentException("key can't be empty");
907 }
908 }
909
910 /**
911 * Gets the value of the specified environment variable. An
912 * environment variable is a system-dependent external named
913 * value.
914 *
915 * <p>If a security manager exists, its
916 * {@link SecurityManager#checkPermission checkPermission}
917 * method is called with a
918 * {@code {@link RuntimePermission}("getenv."+name)}
919 * permission. This may result in a {@link SecurityException}
920 * being thrown. If no exception is thrown the value of the
921 * variable {@code name} is returned.
922 *
923 * <p><a id="EnvironmentVSSystemProperties"><i>System
924 * properties</i> and <i>environment variables</i></a> are both
925 * conceptually mappings between names and values. Both
926 * mechanisms can be used to pass user-defined information to a
927 * Java process. Environment variables have a more global effect,
928 * because they are visible to all descendants of the process
929 * which defines them, not just the immediate Java subprocess.
930 * They can have subtly different semantics, such as case
931 * insensitivity, on different operating systems. For these
932 * reasons, environment variables are more likely to have
933 * unintended side effects. It is best to use system properties
934 * where possible. Environment variables should be used when a
935 * global effect is desired, or when an external system interface
936 * requires an environment variable (such as {@code PATH}).
937 *
938 * <p>On UNIX systems the alphabetic case of {@code name} is
939 * typically significant, while on Microsoft Windows systems it is
940 * typically not. For example, the expression
941 * {@code System.getenv("FOO").equals(System.getenv("foo"))}
942 * is likely to be true on Microsoft Windows.
943 *
944 * @param name the name of the environment variable
945 * @return the string value of the variable, or {@code null}
946 * if the variable is not defined in the system environment
947 * @throws NullPointerException if {@code name} is {@code null}
948 * @throws SecurityException
949 * if a security manager exists and its
950 * {@link SecurityManager#checkPermission checkPermission}
951 * method doesn't allow access to the environment variable
952 * {@code name}
953 * @see #getenv()
954 * @see ProcessBuilder#environment()
955 */
956 public static String getenv(String name) {
957 SecurityManager sm = getSecurityManager();
958 if (sm != null) {
959 sm.checkPermission(new RuntimePermission("getenv."+name));
960 }
961
962 return ProcessEnvironment.getenv(name);
963 }
964
965
966 /**
967 * Returns an unmodifiable string map view of the current system environment.
968 * The environment is a system-dependent mapping from names to
969 * values which is passed from parent to child processes.
970 *
971 * <p>If the system does not support environment variables, an
972 * empty map is returned.
973 *
974 * <p>The returned map will never contain null keys or values.
975 * Attempting to query the presence of a null key or value will
976 * throw a {@link NullPointerException}. Attempting to query
977 * the presence of a key or value which is not of type
978 * {@link String} will throw a {@link ClassCastException}.
979 *
980 * <p>The returned map and its collection views may not obey the
981 * general contract of the {@link Object#equals} and
982 * {@link Object#hashCode} methods.
983 *
984 * <p>The returned map is typically case-sensitive on all platforms.
985 *
986 * <p>If a security manager exists, its
987 * {@link SecurityManager#checkPermission checkPermission}
988 * method is called with a
989 * {@code {@link RuntimePermission}("getenv.*")} permission.
990 * This may result in a {@link SecurityException} being thrown.
991 *
992 * <p>When passing information to a Java subprocess,
993 * <a href=#EnvironmentVSSystemProperties>system properties</a>
994 * are generally preferred over environment variables.
995 *
996 * @return the environment as a map of variable names to values
997 * @throws SecurityException
998 * if a security manager exists and its
999 * {@link SecurityManager#checkPermission checkPermission}
1000 * method doesn't allow access to the process environment
1001 * @see #getenv(String)
1002 * @see ProcessBuilder#environment()
1003 * @since 1.5
1004 */
1005 public static java.util.Map<String,String> getenv() {
1006 SecurityManager sm = getSecurityManager();
1007 if (sm != null) {
1008 sm.checkPermission(new RuntimePermission("getenv.*"));
1009 }
1010
1011 return ProcessEnvironment.getenv();
1012 }
1013
1014 /**
1015 * {@code System.Logger} instances log messages that will be
1016 * routed to the underlying logging framework the {@link System.LoggerFinder
1017 * LoggerFinder} uses.
1018 *
1019 * {@code System.Logger} instances are typically obtained from
1020 * the {@link java.lang.System System} class, by calling
1021 * {@link java.lang.System#getLogger(java.lang.String) System.getLogger(loggerName)}
1022 * or {@link java.lang.System#getLogger(java.lang.String, java.util.ResourceBundle)
1023 * System.getLogger(loggerName, bundle)}.
1024 *
1025 * @see java.lang.System#getLogger(java.lang.String)
1026 * @see java.lang.System#getLogger(java.lang.String, java.util.ResourceBundle)
1027 * @see java.lang.System.LoggerFinder
1028 *
1029 * @since 9
1030 */
1031 public interface Logger {
1032
1033 /**
1034 * System {@linkplain Logger loggers} levels.
1035 *
1036 * A level has a {@linkplain #getName() name} and {@linkplain
1037 * #getSeverity() severity}.
1038 * Level values are {@link #ALL}, {@link #TRACE}, {@link #DEBUG},
1039 * {@link #INFO}, {@link #WARNING}, {@link #ERROR}, {@link #OFF},
1040 * by order of increasing severity.
1041 * <br>
1042 * {@link #ALL} and {@link #OFF}
1043 * are simple markers with severities mapped respectively to
1044 * {@link java.lang.Integer#MIN_VALUE Integer.MIN_VALUE} and
1045 * {@link java.lang.Integer#MAX_VALUE Integer.MAX_VALUE}.
1046 * <p>
1047 * <b>Severity values and Mapping to {@code java.util.logging.Level}.</b>
1048 * <p>
1049 * {@linkplain System.Logger.Level System logger levels} are mapped to
1050 * {@linkplain java.util.logging.Level java.util.logging levels}
1051 * of corresponding severity.
1052 * <br>The mapping is as follows:
1053 * <br><br>
1054 * <table class="striped">
1055 * <caption>System.Logger Severity Level Mapping</caption>
1056 * <thead>
1057 * <tr><th scope="col">System.Logger Levels</th>
1058 * <th scope="col">java.util.logging Levels</th>
1059 * </thead>
1060 * <tbody>
1061 * <tr><th scope="row">{@link Logger.Level#ALL ALL}</th>
1062 * <td>{@link java.util.logging.Level#ALL ALL}</td>
1063 * <tr><th scope="row">{@link Logger.Level#TRACE TRACE}</th>
1064 * <td>{@link java.util.logging.Level#FINER FINER}</td>
1065 * <tr><th scope="row">{@link Logger.Level#DEBUG DEBUG}</th>
1066 * <td>{@link java.util.logging.Level#FINE FINE}</td>
1067 * <tr><th scope="row">{@link Logger.Level#INFO INFO}</th>
1068 * <td>{@link java.util.logging.Level#INFO INFO}</td>
1069 * <tr><th scope="row">{@link Logger.Level#WARNING WARNING}</th>
1070 * <td>{@link java.util.logging.Level#WARNING WARNING}</td>
1071 * <tr><th scope="row">{@link Logger.Level#ERROR ERROR}</th>
1072 * <td>{@link java.util.logging.Level#SEVERE SEVERE}</td>
1073 * <tr><th scope="row">{@link Logger.Level#OFF OFF}</th>
1074 * <td>{@link java.util.logging.Level#OFF OFF}</td>
1075 * </tbody>
1076 * </table>
1077 *
1078 * @since 9
1079 *
1080 * @see java.lang.System.LoggerFinder
1081 * @see java.lang.System.Logger
1082 */
1083 public enum Level {
1084
1085 // for convenience, we're reusing java.util.logging.Level int values
1086 // the mapping logic in sun.util.logging.PlatformLogger depends
1087 // on this.
1088 /**
1089 * A marker to indicate that all levels are enabled.
1090 * This level {@linkplain #getSeverity() severity} is
1091 * {@link Integer#MIN_VALUE}.
1092 */
1093 ALL(Integer.MIN_VALUE), // typically mapped to/from j.u.l.Level.ALL
1094 /**
1095 * {@code TRACE} level: usually used to log diagnostic information.
1096 * This level {@linkplain #getSeverity() severity} is
1097 * {@code 400}.
1098 */
1099 TRACE(400), // typically mapped to/from j.u.l.Level.FINER
1100 /**
1101 * {@code DEBUG} level: usually used to log debug information traces.
1102 * This level {@linkplain #getSeverity() severity} is
1103 * {@code 500}.
1104 */
1105 DEBUG(500), // typically mapped to/from j.u.l.Level.FINEST/FINE/CONFIG
1106 /**
1107 * {@code INFO} level: usually used to log information messages.
1108 * This level {@linkplain #getSeverity() severity} is
1109 * {@code 800}.
1110 */
1111 INFO(800), // typically mapped to/from j.u.l.Level.INFO
1112 /**
1113 * {@code WARNING} level: usually used to log warning messages.
1114 * This level {@linkplain #getSeverity() severity} is
1115 * {@code 900}.
1116 */
1117 WARNING(900), // typically mapped to/from j.u.l.Level.WARNING
1118 /**
1119 * {@code ERROR} level: usually used to log error messages.
1120 * This level {@linkplain #getSeverity() severity} is
1121 * {@code 1000}.
1122 */
1123 ERROR(1000), // typically mapped to/from j.u.l.Level.SEVERE
1124 /**
1125 * A marker to indicate that all levels are disabled.
1126 * This level {@linkplain #getSeverity() severity} is
1127 * {@link Integer#MAX_VALUE}.
1128 */
1129 OFF(Integer.MAX_VALUE); // typically mapped to/from j.u.l.Level.OFF
1130
1131 private final int severity;
1132
1133 private Level(int severity) {
1134 this.severity = severity;
1135 }
1136
1137 /**
1138 * Returns the name of this level.
1139 * @return this level {@linkplain #name()}.
1140 */
1141 public final String getName() {
1142 return name();
1143 }
1144
1145 /**
1146 * Returns the severity of this level.
1147 * A higher severity means a more severe condition.
1148 * @return this level severity.
1149 */
1150 public final int getSeverity() {
1151 return severity;
1152 }
1153 }
1154
1155 /**
1156 * Returns the name of this logger.
1157 *
1158 * @return the logger name.
1159 */
1160 public String getName();
1161
1162 /**
1163 * Checks if a message of the given level would be logged by
1164 * this logger.
1165 *
1166 * @param level the log message level.
1167 * @return {@code true} if the given log message level is currently
1168 * being logged.
1169 *
1170 * @throws NullPointerException if {@code level} is {@code null}.
1171 */
1172 public boolean isLoggable(Level level);
1173
1174 /**
1175 * Logs a message.
1176 *
1177 * @implSpec The default implementation for this method calls
1178 * {@code this.log(level, (ResourceBundle)null, msg, (Object[])null);}
1179 *
1180 * @param level the log message level.
1181 * @param msg the string message (or a key in the message catalog, if
1182 * this logger is a {@link
1183 * LoggerFinder#getLocalizedLogger(java.lang.String,
1184 * java.util.ResourceBundle, java.lang.Module) localized logger});
1185 * can be {@code null}.
1186 *
1187 * @throws NullPointerException if {@code level} is {@code null}.
1188 */
1189 public default void log(Level level, String msg) {
1190 log(level, (ResourceBundle) null, msg, (Object[]) null);
1191 }
1192
1193 /**
1194 * Logs a lazily supplied message.
1195 *
1196 * If the logger is currently enabled for the given log message level
1197 * then a message is logged that is the result produced by the
1198 * given supplier function. Otherwise, the supplier is not operated on.
1199 *
1200 * @implSpec When logging is enabled for the given level, the default
1201 * implementation for this method calls
1202 * {@code this.log(level, (ResourceBundle)null, msgSupplier.get(), (Object[])null);}
1203 *
1204 * @param level the log message level.
1205 * @param msgSupplier a supplier function that produces a message.
1206 *
1207 * @throws NullPointerException if {@code level} is {@code null},
1208 * or {@code msgSupplier} is {@code null}.
1209 */
1210 public default void log(Level level, Supplier<String> msgSupplier) {
1211 Objects.requireNonNull(msgSupplier);
1212 if (isLoggable(Objects.requireNonNull(level))) {
1213 log(level, (ResourceBundle) null, msgSupplier.get(), (Object[]) null);
1214 }
1215 }
1216
1217 /**
1218 * Logs a message produced from the given object.
1219 *
1220 * If the logger is currently enabled for the given log message level then
1221 * a message is logged that, by default, is the result produced from
1222 * calling toString on the given object.
1223 * Otherwise, the object is not operated on.
1224 *
1225 * @implSpec When logging is enabled for the given level, the default
1226 * implementation for this method calls
1227 * {@code this.log(level, (ResourceBundle)null, obj.toString(), (Object[])null);}
1228 *
1229 * @param level the log message level.
1230 * @param obj the object to log.
1231 *
1232 * @throws NullPointerException if {@code level} is {@code null}, or
1233 * {@code obj} is {@code null}.
1234 */
1235 public default void log(Level level, Object obj) {
1236 Objects.requireNonNull(obj);
1237 if (isLoggable(Objects.requireNonNull(level))) {
1238 this.log(level, (ResourceBundle) null, obj.toString(), (Object[]) null);
1239 }
1240 }
1241
1242 /**
1243 * Logs a message associated with a given throwable.
1244 *
1245 * @implSpec The default implementation for this method calls
1246 * {@code this.log(level, (ResourceBundle)null, msg, thrown);}
1247 *
1248 * @param level the log message level.
1249 * @param msg the string message (or a key in the message catalog, if
1250 * this logger is a {@link
1251 * LoggerFinder#getLocalizedLogger(java.lang.String,
1252 * java.util.ResourceBundle, java.lang.Module) localized logger});
1253 * can be {@code null}.
1254 * @param thrown a {@code Throwable} associated with the log message;
1255 * can be {@code null}.
1256 *
1257 * @throws NullPointerException if {@code level} is {@code null}.
1258 */
1259 public default void log(Level level, String msg, Throwable thrown) {
1260 this.log(level, null, msg, thrown);
1261 }
1262
1263 /**
1264 * Logs a lazily supplied message associated with a given throwable.
1265 *
1266 * If the logger is currently enabled for the given log message level
1267 * then a message is logged that is the result produced by the
1268 * given supplier function. Otherwise, the supplier is not operated on.
1269 *
1270 * @implSpec When logging is enabled for the given level, the default
1271 * implementation for this method calls
1272 * {@code this.log(level, (ResourceBundle)null, msgSupplier.get(), thrown);}
1273 *
1274 * @param level one of the log message level identifiers.
1275 * @param msgSupplier a supplier function that produces a message.
1276 * @param thrown a {@code Throwable} associated with log message;
1277 * can be {@code null}.
1278 *
1279 * @throws NullPointerException if {@code level} is {@code null}, or
1280 * {@code msgSupplier} is {@code null}.
1281 */
1282 public default void log(Level level, Supplier<String> msgSupplier,
1283 Throwable thrown) {
1284 Objects.requireNonNull(msgSupplier);
1285 if (isLoggable(Objects.requireNonNull(level))) {
1286 this.log(level, null, msgSupplier.get(), thrown);
1287 }
1288 }
1289
1290 /**
1291 * Logs a message with an optional list of parameters.
1292 *
1293 * @implSpec The default implementation for this method calls
1294 * {@code this.log(level, (ResourceBundle)null, format, params);}
1295 *
1296 * @param level one of the log message level identifiers.
1297 * @param format the string message format in {@link
1298 * java.text.MessageFormat} format, (or a key in the message
1299 * catalog, if this logger is a {@link
1300 * LoggerFinder#getLocalizedLogger(java.lang.String,
1301 * java.util.ResourceBundle, java.lang.Module) localized logger});
1302 * can be {@code null}.
1303 * @param params an optional list of parameters to the message (may be
1304 * none).
1305 *
1306 * @throws NullPointerException if {@code level} is {@code null}.
1307 */
1308 public default void log(Level level, String format, Object... params) {
1309 this.log(level, null, format, params);
1310 }
1311
1312 /**
1313 * Logs a localized message associated with a given throwable.
1314 *
1315 * If the given resource bundle is non-{@code null}, the {@code msg}
1316 * string is localized using the given resource bundle.
1317 * Otherwise the {@code msg} string is not localized.
1318 *
1319 * @param level the log message level.
1320 * @param bundle a resource bundle to localize {@code msg}; can be
1321 * {@code null}.
1322 * @param msg the string message (or a key in the message catalog,
1323 * if {@code bundle} is not {@code null}); can be {@code null}.
1324 * @param thrown a {@code Throwable} associated with the log message;
1325 * can be {@code null}.
1326 *
1327 * @throws NullPointerException if {@code level} is {@code null}.
1328 */
1329 public void log(Level level, ResourceBundle bundle, String msg,
1330 Throwable thrown);
1331
1332 /**
1333 * Logs a message with resource bundle and an optional list of
1334 * parameters.
1335 *
1336 * If the given resource bundle is non-{@code null}, the {@code format}
1337 * string is localized using the given resource bundle.
1338 * Otherwise the {@code format} string is not localized.
1339 *
1340 * @param level the log message level.
1341 * @param bundle a resource bundle to localize {@code format}; can be
1342 * {@code null}.
1343 * @param format the string message format in {@link
1344 * java.text.MessageFormat} format, (or a key in the message
1345 * catalog if {@code bundle} is not {@code null}); can be {@code null}.
1346 * @param params an optional list of parameters to the message (may be
1347 * none).
1348 *
1349 * @throws NullPointerException if {@code level} is {@code null}.
1350 */
1351 public void log(Level level, ResourceBundle bundle, String format,
1352 Object... params);
1353 }
1354
1355 /**
1356 * The {@code LoggerFinder} service is responsible for creating, managing,
1357 * and configuring loggers to the underlying framework it uses.
1358 *
1359 * A logger finder is a concrete implementation of this class that has a
1360 * zero-argument constructor and implements the abstract methods defined
1361 * by this class.
1362 * The loggers returned from a logger finder are capable of routing log
1363 * messages to the logging backend this provider supports.
1364 * A given invocation of the Java Runtime maintains a single
1365 * system-wide LoggerFinder instance that is loaded as follows:
1366 * <ul>
1367 * <li>First it finds any custom {@code LoggerFinder} provider
1368 * using the {@link java.util.ServiceLoader} facility with the
1369 * {@linkplain ClassLoader#getSystemClassLoader() system class
1370 * loader}.</li>
1371 * <li>If no {@code LoggerFinder} provider is found, the system default
1372 * {@code LoggerFinder} implementation will be used.</li>
1373 * </ul>
1374 * <p>
1375 * An application can replace the logging backend
1376 * <i>even when the java.logging module is present</i>, by simply providing
1377 * and declaring an implementation of the {@link LoggerFinder} service.
1378 * <p>
1379 * <b>Default Implementation</b>
1380 * <p>
1381 * The system default {@code LoggerFinder} implementation uses
1382 * {@code java.util.logging} as the backend framework when the
1383 * {@code java.logging} module is present.
1384 * It returns a {@linkplain System.Logger logger} instance
1385 * that will route log messages to a {@link java.util.logging.Logger
1386 * java.util.logging.Logger}. Otherwise, if {@code java.logging} is not
1387 * present, the default implementation will return a simple logger
1388 * instance that will route log messages of {@code INFO} level and above to
1389 * the console ({@code System.err}).
1390 * <p>
1391 * <b>Logging Configuration</b>
1392 * <p>
1393 * {@linkplain Logger Logger} instances obtained from the
1394 * {@code LoggerFinder} factory methods are not directly configurable by
1395 * the application. Configuration is the responsibility of the underlying
1396 * logging backend, and usually requires using APIs specific to that backend.
1397 * <p>For the default {@code LoggerFinder} implementation
1398 * using {@code java.util.logging} as its backend, refer to
1399 * {@link java.util.logging java.util.logging} for logging configuration.
1400 * For the default {@code LoggerFinder} implementation returning simple loggers
1401 * when the {@code java.logging} module is absent, the configuration
1402 * is implementation dependent.
1403 * <p>
1404 * Usually an application that uses a logging framework will log messages
1405 * through a logger facade defined (or supported) by that framework.
1406 * Applications that wish to use an external framework should log
1407 * through the facade associated with that framework.
1408 * <p>
1409 * A system class that needs to log messages will typically obtain
1410 * a {@link System.Logger} instance to route messages to the logging
1411 * framework selected by the application.
1412 * <p>
1413 * Libraries and classes that only need loggers to produce log messages
1414 * should not attempt to configure loggers by themselves, as that
1415 * would make them dependent from a specific implementation of the
1416 * {@code LoggerFinder} service.
1417 * <p>
1418 * In addition, when a security manager is present, loggers provided to
1419 * system classes should not be directly configurable through the logging
1420 * backend without requiring permissions.
1421 * <br>
1422 * It is the responsibility of the provider of
1423 * the concrete {@code LoggerFinder} implementation to ensure that
1424 * these loggers are not configured by untrusted code without proper
1425 * permission checks, as configuration performed on such loggers usually
1426 * affects all applications in the same Java Runtime.
1427 * <p>
1428 * <b>Message Levels and Mapping to backend levels</b>
1429 * <p>
1430 * A logger finder is responsible for mapping from a {@code
1431 * System.Logger.Level} to a level supported by the logging backend it uses.
1432 * <br>The default LoggerFinder using {@code java.util.logging} as the backend
1433 * maps {@code System.Logger} levels to
1434 * {@linkplain java.util.logging.Level java.util.logging} levels
1435 * of corresponding severity - as described in {@link Logger.Level
1436 * Logger.Level}.
1437 *
1438 * @see java.lang.System
1439 * @see java.lang.System.Logger
1440 *
1441 * @since 9
1442 */
1443 public static abstract class LoggerFinder {
1444 /**
1445 * The {@code RuntimePermission("loggerFinder")} is
1446 * necessary to subclass and instantiate the {@code LoggerFinder} class,
1447 * as well as to obtain loggers from an instance of that class.
1448 */
1449 static final RuntimePermission LOGGERFINDER_PERMISSION =
1450 new RuntimePermission("loggerFinder");
1451
1452 /**
1453 * Creates a new instance of {@code LoggerFinder}.
1454 *
1455 * @implNote It is recommended that a {@code LoggerFinder} service
1456 * implementation does not perform any heavy initialization in its
1457 * constructor, in order to avoid possible risks of deadlock or class
1458 * loading cycles during the instantiation of the service provider.
1459 *
1460 * @throws SecurityException if a security manager is present and its
1461 * {@code checkPermission} method doesn't allow the
1462 * {@code RuntimePermission("loggerFinder")}.
1463 */
1464 protected LoggerFinder() {
1465 this(checkPermission());
1466 }
1467
1468 private LoggerFinder(Void unused) {
1469 // nothing to do.
1470 }
1471
1472 private static Void checkPermission() {
1473 final SecurityManager sm = System.getSecurityManager();
1474 if (sm != null) {
1475 sm.checkPermission(LOGGERFINDER_PERMISSION);
1476 }
1477 return null;
1478 }
1479
1480 /**
1481 * Returns an instance of {@link Logger Logger}
1482 * for the given {@code module}.
1483 *
1484 * @param name the name of the logger.
1485 * @param module the module for which the logger is being requested.
1486 *
1487 * @return a {@link Logger logger} suitable for use within the given
1488 * module.
1489 * @throws NullPointerException if {@code name} is {@code null} or
1490 * {@code module} is {@code null}.
1491 * @throws SecurityException if a security manager is present and its
1492 * {@code checkPermission} method doesn't allow the
1493 * {@code RuntimePermission("loggerFinder")}.
1494 */
1495 public abstract Logger getLogger(String name, Module module);
1496
1497 /**
1498 * Returns a localizable instance of {@link Logger Logger}
1499 * for the given {@code module}.
1500 * The returned logger will use the provided resource bundle for
1501 * message localization.
1502 *
1503 * @implSpec By default, this method calls {@link
1504 * #getLogger(java.lang.String, java.lang.Module)
1505 * this.getLogger(name, module)} to obtain a logger, then wraps that
1506 * logger in a {@link Logger} instance where all methods that do not
1507 * take a {@link ResourceBundle} as parameter are redirected to one
1508 * which does - passing the given {@code bundle} for
1509 * localization. So for instance, a call to {@link
1510 * Logger#log(Logger.Level, String) Logger.log(Level.INFO, msg)}
1511 * will end up as a call to {@link
1512 * Logger#log(Logger.Level, ResourceBundle, String, Object...)
1513 * Logger.log(Level.INFO, bundle, msg, (Object[])null)} on the wrapped
1514 * logger instance.
1515 * Note however that by default, string messages returned by {@link
1516 * java.util.function.Supplier Supplier<String>} will not be
1517 * localized, as it is assumed that such strings are messages which are
1518 * already constructed, rather than keys in a resource bundle.
1519 * <p>
1520 * An implementation of {@code LoggerFinder} may override this method,
1521 * for example, when the underlying logging backend provides its own
1522 * mechanism for localizing log messages, then such a
1523 * {@code LoggerFinder} would be free to return a logger
1524 * that makes direct use of the mechanism provided by the backend.
1525 *
1526 * @param name the name of the logger.
1527 * @param bundle a resource bundle; can be {@code null}.
1528 * @param module the module for which the logger is being requested.
1529 * @return an instance of {@link Logger Logger} which will use the
1530 * provided resource bundle for message localization.
1531 *
1532 * @throws NullPointerException if {@code name} is {@code null} or
1533 * {@code module} is {@code null}.
1534 * @throws SecurityException if a security manager is present and its
1535 * {@code checkPermission} method doesn't allow the
1536 * {@code RuntimePermission("loggerFinder")}.
1537 */
1538 public Logger getLocalizedLogger(String name, ResourceBundle bundle,
1539 Module module) {
1540 return new LocalizedLoggerWrapper<>(getLogger(name, module), bundle);
1541 }
1542
1543 /**
1544 * Returns the {@code LoggerFinder} instance. There is one
1545 * single system-wide {@code LoggerFinder} instance in
1546 * the Java Runtime. See the class specification of how the
1547 * {@link LoggerFinder LoggerFinder} implementation is located and
1548 * loaded.
1549
1550 * @return the {@link LoggerFinder LoggerFinder} instance.
1551 * @throws SecurityException if a security manager is present and its
1552 * {@code checkPermission} method doesn't allow the
1553 * {@code RuntimePermission("loggerFinder")}.
1554 */
1555 public static LoggerFinder getLoggerFinder() {
1556 final SecurityManager sm = System.getSecurityManager();
1557 if (sm != null) {
1558 sm.checkPermission(LOGGERFINDER_PERMISSION);
1559 }
1560 return accessProvider();
1561 }
1562
1563
1564 private static volatile LoggerFinder service;
1565 static LoggerFinder accessProvider() {
1566 // We do not need to synchronize: LoggerFinderLoader will
1567 // always return the same instance, so if we don't have it,
1568 // just fetch it again.
1569 if (service == null) {
1570 PrivilegedAction<LoggerFinder> pa =
1571 () -> LoggerFinderLoader.getLoggerFinder();
1572 service = AccessController.doPrivileged(pa, null,
1573 LOGGERFINDER_PERMISSION);
1574 }
1575 return service;
1576 }
1577
1578 }
1579
1580
1581 /**
1582 * Returns an instance of {@link Logger Logger} for the caller's
1583 * use.
1584 *
1585 * @implSpec
1586 * Instances returned by this method route messages to loggers
1587 * obtained by calling {@link LoggerFinder#getLogger(java.lang.String,
1588 * java.lang.Module) LoggerFinder.getLogger(name, module)}, where
1589 * {@code module} is the caller's module.
1590 * In cases where {@code System.getLogger} is called from a context where
1591 * there is no caller frame on the stack (e.g when called directly
1592 * from a JNI attached thread), {@code IllegalCallerException} is thrown.
1593 * To obtain a logger in such a context, use an auxiliary class that will
1594 * implicitly be identified as the caller, or use the system {@link
1595 * LoggerFinder#getLoggerFinder() LoggerFinder} to obtain a logger instead.
1596 * Note that doing the latter may eagerly initialize the underlying
1597 * logging system.
1598 *
1599 * @apiNote
1600 * This method may defer calling the {@link
1601 * LoggerFinder#getLogger(java.lang.String, java.lang.Module)
1602 * LoggerFinder.getLogger} method to create an actual logger supplied by
1603 * the logging backend, for instance, to allow loggers to be obtained during
1604 * the system initialization time.
1605 *
1606 * @param name the name of the logger.
1607 * @return an instance of {@link Logger} that can be used by the calling
1608 * class.
1609 * @throws NullPointerException if {@code name} is {@code null}.
1610 * @throws IllegalCallerException if there is no Java caller frame on the
1611 * stack.
1612 *
1613 * @since 9
1614 */
1615 @CallerSensitive
1616 public static Logger getLogger(String name) {
1617 Objects.requireNonNull(name);
1618 final Class<?> caller = Reflection.getCallerClass();
1619 if (caller == null) {
1620 throw new IllegalCallerException("no caller frame");
1621 }
1622 return LazyLoggers.getLogger(name, caller.getModule());
1623 }
1624
1625 /**
1626 * Returns a localizable instance of {@link Logger
1627 * Logger} for the caller's use.
1628 * The returned logger will use the provided resource bundle for message
1629 * localization.
1630 *
1631 * @implSpec
1632 * The returned logger will perform message localization as specified
1633 * by {@link LoggerFinder#getLocalizedLogger(java.lang.String,
1634 * java.util.ResourceBundle, java.lang.Module)
1635 * LoggerFinder.getLocalizedLogger(name, bundle, module)}, where
1636 * {@code module} is the caller's module.
1637 * In cases where {@code System.getLogger} is called from a context where
1638 * there is no caller frame on the stack (e.g when called directly
1639 * from a JNI attached thread), {@code IllegalCallerException} is thrown.
1640 * To obtain a logger in such a context, use an auxiliary class that
1641 * will implicitly be identified as the caller, or use the system {@link
1642 * LoggerFinder#getLoggerFinder() LoggerFinder} to obtain a logger instead.
1643 * Note that doing the latter may eagerly initialize the underlying
1644 * logging system.
1645 *
1646 * @apiNote
1647 * This method is intended to be used after the system is fully initialized.
1648 * This method may trigger the immediate loading and initialization
1649 * of the {@link LoggerFinder} service, which may cause issues if the
1650 * Java Runtime is not ready to initialize the concrete service
1651 * implementation yet.
1652 * System classes which may be loaded early in the boot sequence and
1653 * need to log localized messages should create a logger using
1654 * {@link #getLogger(java.lang.String)} and then use the log methods that
1655 * take a resource bundle as parameter.
1656 *
1657 * @param name the name of the logger.
1658 * @param bundle a resource bundle.
1659 * @return an instance of {@link Logger} which will use the provided
1660 * resource bundle for message localization.
1661 * @throws NullPointerException if {@code name} is {@code null} or
1662 * {@code bundle} is {@code null}.
1663 * @throws IllegalCallerException if there is no Java caller frame on the
1664 * stack.
1665 *
1666 * @since 9
1667 */
1668 @CallerSensitive
1669 public static Logger getLogger(String name, ResourceBundle bundle) {
1670 final ResourceBundle rb = Objects.requireNonNull(bundle);
1671 Objects.requireNonNull(name);
1672 final Class<?> caller = Reflection.getCallerClass();
1673 if (caller == null) {
1674 throw new IllegalCallerException("no caller frame");
1675 }
1676 final SecurityManager sm = System.getSecurityManager();
1677 // We don't use LazyLoggers if a resource bundle is specified.
1678 // Bootstrap sensitive classes in the JDK do not use resource bundles
1679 // when logging. This could be revisited later, if it needs to.
1680 if (sm != null) {
1681 final PrivilegedAction<Logger> pa =
1682 () -> LoggerFinder.accessProvider()
1683 .getLocalizedLogger(name, rb, caller.getModule());
1684 return AccessController.doPrivileged(pa, null,
1685 LoggerFinder.LOGGERFINDER_PERMISSION);
1686 }
1687 return LoggerFinder.accessProvider()
1688 .getLocalizedLogger(name, rb, caller.getModule());
1689 }
1690
1691 /**
1692 * Terminates the currently running Java Virtual Machine. The
1693 * argument serves as a status code; by convention, a nonzero status
1694 * code indicates abnormal termination.
1695 * <p>
1696 * This method calls the {@code exit} method in class
1697 * {@code Runtime}. This method never returns normally.
1698 * <p>
1699 * The call {@code System.exit(n)} is effectively equivalent to
1700 * the call:
1701 * <blockquote><pre>
1702 * Runtime.getRuntime().exit(n)
1703 * </pre></blockquote>
1704 *
1705 * @param status exit status.
1706 * @throws SecurityException
1707 * if a security manager exists and its {@code checkExit}
1708 * method doesn't allow exit with the specified status.
1709 * @see java.lang.Runtime#exit(int)
1710 */
1711 public static void exit(int status) {
1712 Runtime.getRuntime().exit(status);
1713 }
1714
1715 /**
1716 * Runs the garbage collector.
1717 *
1718 * Calling the {@code gc} method suggests that the Java Virtual
1719 * Machine expend effort toward recycling unused objects in order to
1720 * make the memory they currently occupy available for quick reuse.
1721 * When control returns from the method call, the Java Virtual
1722 * Machine has made a best effort to reclaim space from all discarded
1723 * objects.
1724 * <p>
1725 * The call {@code System.gc()} is effectively equivalent to the
1726 * call:
1727 * <blockquote><pre>
1728 * Runtime.getRuntime().gc()
1729 * </pre></blockquote>
1730 *
1731 * @see java.lang.Runtime#gc()
1732 */
1733 public static void gc() {
1734 Runtime.getRuntime().gc();
1735 }
1736
1737 /**
1738 * Runs the finalization methods of any objects pending finalization.
1739 *
1740 * Calling this method suggests that the Java Virtual Machine expend
1741 * effort toward running the {@code finalize} methods of objects
1742 * that have been found to be discarded but whose {@code finalize}
1743 * methods have not yet been run. When control returns from the
1744 * method call, the Java Virtual Machine has made a best effort to
1745 * complete all outstanding finalizations.
1746 * <p>
1747 * The call {@code System.runFinalization()} is effectively
1748 * equivalent to the call:
1749 * <blockquote><pre>
1750 * Runtime.getRuntime().runFinalization()
1751 * </pre></blockquote>
1752 *
1753 * @see java.lang.Runtime#runFinalization()
1754 */
1755 public static void runFinalization() {
1756 Runtime.getRuntime().runFinalization();
1757 }
1758
1759 /**
1760 * Loads the native library specified by the filename argument. The filename
1761 * argument must be an absolute path name.
1762 *
1763 * If the filename argument, when stripped of any platform-specific library
1764 * prefix, path, and file extension, indicates a library whose name is,
1765 * for example, L, and a native library called L is statically linked
1766 * with the VM, then the JNI_OnLoad_L function exported by the library
1767 * is invoked rather than attempting to load a dynamic library.
1768 * A filename matching the argument does not have to exist in the
1769 * file system.
1770 * See the <a href="{@docRoot}/../specs/jni/index.html"> JNI Specification</a>
1771 * for more details.
1772 *
1773 * Otherwise, the filename argument is mapped to a native library image in
1774 * an implementation-dependent manner.
1775 *
1776 * <p>
1777 * The call {@code System.load(name)} is effectively equivalent
1778 * to the call:
1779 * <blockquote><pre>
1780 * Runtime.getRuntime().load(name)
1781 * </pre></blockquote>
1782 *
1783 * @param filename the file to load.
1784 * @throws SecurityException if a security manager exists and its
1785 * {@code checkLink} method doesn't allow
1786 * loading of the specified dynamic library
1787 * @throws UnsatisfiedLinkError if either the filename is not an
1788 * absolute path name, the native library is not statically
1789 * linked with the VM, or the library cannot be mapped to
1790 * a native library image by the host system.
1791 * @throws NullPointerException if {@code filename} is {@code null}
1792 * @see java.lang.Runtime#load(java.lang.String)
1793 * @see java.lang.SecurityManager#checkLink(java.lang.String)
1794 */
1795 @CallerSensitive
1796 public static void load(String filename) {
1797 Runtime.getRuntime().load0(Reflection.getCallerClass(), filename);
1798 }
1799
1800 /**
1801 * Loads the native library specified by the {@code libname}
1802 * argument. The {@code libname} argument must not contain any platform
1803 * specific prefix, file extension or path. If a native library
1804 * called {@code libname} is statically linked with the VM, then the
1805 * JNI_OnLoad_{@code libname} function exported by the library is invoked.
1806 * See the <a href="{@docRoot}/../specs/jni/index.html"> JNI Specification</a>
1807 * for more details.
1808 *
1809 * Otherwise, the libname argument is loaded from a system library
1810 * location and mapped to a native library image in an implementation-
1811 * dependent manner.
1812 * <p>
1813 * The call {@code System.loadLibrary(name)} is effectively
1814 * equivalent to the call
1815 * <blockquote><pre>
1816 * Runtime.getRuntime().loadLibrary(name)
1817 * </pre></blockquote>
1818 *
1819 * @param libname the name of the library.
1820 * @throws SecurityException if a security manager exists and its
1821 * {@code checkLink} method doesn't allow
1822 * loading of the specified dynamic library
1823 * @throws UnsatisfiedLinkError if either the libname argument
1824 * contains a file path, the native library is not statically
1825 * linked with the VM, or the library cannot be mapped to a
1826 * native library image by the host system.
1827 * @throws NullPointerException if {@code libname} is {@code null}
1828 * @see java.lang.Runtime#loadLibrary(java.lang.String)
1829 * @see java.lang.SecurityManager#checkLink(java.lang.String)
1830 */
1831 @CallerSensitive
1832 public static void loadLibrary(String libname) {
1833 Runtime.getRuntime().loadLibrary0(Reflection.getCallerClass(), libname);
1834 }
1835
1836 /**
1837 * Maps a library name into a platform-specific string representing
1838 * a native library.
1839 *
1840 * @param libname the name of the library.
1841 * @return a platform-dependent native library name.
1842 * @throws NullPointerException if {@code libname} is {@code null}
1843 * @see java.lang.System#loadLibrary(java.lang.String)
1844 * @see java.lang.ClassLoader#findLibrary(java.lang.String)
1845 * @since 1.2
1846 */
1847 public static native String mapLibraryName(String libname);
1848
1849 /**
1850 * Create PrintStream for stdout/err based on encoding.
1851 */
1852 private static PrintStream newPrintStream(FileOutputStream fos, String enc) {
1853 if (enc != null) {
1854 try {
1855 return new PrintStream(new BufferedOutputStream(fos, 128), true, enc);
1856 } catch (UnsupportedEncodingException uee) {}
1857 }
1858 return new PrintStream(new BufferedOutputStream(fos, 128), true);
1859 }
1860
1861 /**
1862 * Logs an exception/error at initialization time to stdout or stderr.
1863 *
1864 * @param printToStderr to print to stderr rather than stdout
1865 * @param printStackTrace to print the stack trace
1866 * @param msg the message to print before the exception, can be {@code null}
1867 * @param e the exception or error
1868 */
1869 private static void logInitException(boolean printToStderr,
1870 boolean printStackTrace,
1871 String msg,
1872 Throwable e) {
1873 if (VM.initLevel() < 1) {
1874 throw new InternalError("system classes not initialized");
1875 }
1876 PrintStream log = (printToStderr) ? err : out;
1877 if (msg != null) {
1878 log.println(msg);
1879 }
1880 if (printStackTrace) {
1881 e.printStackTrace(log);
1882 } else {
1883 log.println(e);
1884 for (Throwable suppressed : e.getSuppressed()) {
1885 log.println("Suppressed: " + suppressed);
1886 }
1887 Throwable cause = e.getCause();
1888 if (cause != null) {
1889 log.println("Caused by: " + cause);
1890 }
1891 }
1892 }
1893
1894 /**
1895 * Initialize the system class. Called after thread initialization.
1896 */
1897 private static void initPhase1() {
1898
1899 // VM might invoke JNU_NewStringPlatform() to set those encoding
1900 // sensitive properties (user.home, user.name, boot.class.path, etc.)
1901 // during "props" initialization, in which it may need access, via
1902 // System.getProperty(), to the related system encoding property that
1903 // have been initialized (put into "props") at early stage of the
1904 // initialization. So make sure the "props" is available at the
1905 // very beginning of the initialization and all system properties to
1906 // be put into it directly.
1907 props = new Properties(84);
1908 initProperties(props); // initialized by the VM
1909
1910 // There are certain system configurations that may be controlled by
1911 // VM options such as the maximum amount of direct memory and
1912 // Integer cache size used to support the object identity semantics
1913 // of autoboxing. Typically, the library will obtain these values
1914 // from the properties set by the VM. If the properties are for
1915 // internal implementation use only, these properties should be
1916 // removed from the system properties.
1917 //
1918 // See java.lang.Integer.IntegerCache and the
1919 // VM.saveAndRemoveProperties method for example.
1920 //
1921 // Save a private copy of the system properties object that
1922 // can only be accessed by the internal implementation. Remove
1923 // certain system properties that are not intended for public access.
1924 VM.saveAndRemoveProperties(props);
1925
1926 lineSeparator = props.getProperty("line.separator");
1927 VersionProps.init();
1928
1929 FileInputStream fdIn = new FileInputStream(FileDescriptor.in);
1930 FileOutputStream fdOut = new FileOutputStream(FileDescriptor.out);
1931 FileOutputStream fdErr = new FileOutputStream(FileDescriptor.err);
1932 setIn0(new BufferedInputStream(fdIn));
1933 setOut0(newPrintStream(fdOut, props.getProperty("sun.stdout.encoding")));
1934 setErr0(newPrintStream(fdErr, props.getProperty("sun.stderr.encoding")));
1935
1936 // Setup Java signal handlers for HUP, TERM, and INT (where available).
1937 Terminator.setup();
1938
1939 // Initialize any miscellaneous operating system settings that need to be
1940 // set for the class libraries. Currently this is no-op everywhere except
1941 // for Windows where the process-wide error mode is set before the java.io
1942 // classes are used.
1943 VM.initializeOSEnvironment();
1944
1945 // The main thread is not added to its thread group in the same
1946 // way as other threads; we must do it ourselves here.
1947 Thread current = Thread.currentThread();
1948 current.getThreadGroup().add(current);
1949
1950 // register shared secrets
1951 setJavaLangAccess();
1952
1953 // Subsystems that are invoked during initialization can invoke
1954 // VM.isBooted() in order to avoid doing things that should
1955 // wait until the VM is fully initialized. The initialization level
1956 // is incremented from 0 to 1 here to indicate the first phase of
1957 // initialization has completed.
1958 // IMPORTANT: Ensure that this remains the last initialization action!
1959 VM.initLevel(1);
1960 }
1961
1962 // @see #initPhase2()
1963 static ModuleLayer bootLayer;
1964
1965 /*
1966 * Invoked by VM. Phase 2 module system initialization.
1967 * Only classes in java.base can be loaded in this phase.
1968 *
1969 * @param printToStderr print exceptions to stderr rather than stdout
1970 * @param printStackTrace print stack trace when exception occurs
1971 *
1972 * @return JNI_OK for success, JNI_ERR for failure
1973 */
1974 private static int initPhase2(boolean printToStderr, boolean printStackTrace) {
1975 try {
1976 bootLayer = ModuleBootstrap.boot();
1977 } catch (Exception | Error e) {
1978 logInitException(printToStderr, printStackTrace,
1979 "Error occurred during initialization of boot layer", e);
1980 return -1; // JNI_ERR
1981 }
1982
1983 // module system initialized
1984 VM.initLevel(2);
1985
1986 return 0; // JNI_OK
1987 }
1988
1989 /*
1990 * Invoked by VM. Phase 3 is the final system initialization:
1991 * 1. set security manager
1992 * 2. set system class loader
1993 * 3. set TCCL
1994 *
1995 * This method must be called after the module system initialization.
1996 * The security manager and system class loader may be custom class from
1997 * the application classpath or modulepath.
1998 */
1999 private static void initPhase3() {
2000 // set security manager
2001 String cn = System.getProperty("java.security.manager");
2002 if (cn != null) {
2003 if (cn.isEmpty() || "default".equals(cn)) {
2004 System.setSecurityManager(new SecurityManager());
2005 } else {
2006 try {
2007 Class<?> c = Class.forName(cn, false, ClassLoader.getBuiltinAppClassLoader());
2008 Constructor<?> ctor = c.getConstructor();
2009 // Must be a public subclass of SecurityManager with
2010 // a public no-arg constructor
2011 if (!SecurityManager.class.isAssignableFrom(c) ||
2012 !Modifier.isPublic(c.getModifiers()) ||
2013 !Modifier.isPublic(ctor.getModifiers())) {
2014 throw new Error("Could not create SecurityManager: " + ctor.toString());
2015 }
2016 // custom security manager implementation may be in unnamed module
2017 // or a named module but non-exported package
2018 ctor.setAccessible(true);
2019 SecurityManager sm = (SecurityManager) ctor.newInstance();
2020 System.setSecurityManager(sm);
2021 } catch (Exception e) {
2022 throw new Error("Could not create SecurityManager", e);
2023 }
2024 }
2025 }
2026
2027 // initializing the system class loader
2028 VM.initLevel(3);
2029
2030 // system class loader initialized
2031 ClassLoader scl = ClassLoader.initSystemClassLoader();
2032
2033 // set TCCL
2034 Thread.currentThread().setContextClassLoader(scl);
2035
2036 // system is fully initialized
2037 VM.initLevel(4);
2038 }
2039
2040 private static void setJavaLangAccess() {
2041 // Allow privileged classes outside of java.lang
2042 SharedSecrets.setJavaLangAccess(new JavaLangAccess() {
2043 public List<Method> getDeclaredPublicMethods(Class<?> klass, String name, Class<?>... parameterTypes) {
2044 return klass.getDeclaredPublicMethods(name, parameterTypes);
2045 }
2046 public jdk.internal.reflect.ConstantPool getConstantPool(Class<?> klass) {
2047 return klass.getConstantPool();
2048 }
2049 public boolean casAnnotationType(Class<?> klass, AnnotationType oldType, AnnotationType newType) {
2050 return klass.casAnnotationType(oldType, newType);
2051 }
2052 public AnnotationType getAnnotationType(Class<?> klass) {
2053 return klass.getAnnotationType();
2054 }
2055 public Map<Class<? extends Annotation>, Annotation> getDeclaredAnnotationMap(Class<?> klass) {
2056 return klass.getDeclaredAnnotationMap();
2057 }
2058 public byte[] getRawClassAnnotations(Class<?> klass) {
2059 return klass.getRawAnnotations();
2060 }
2061 public byte[] getRawClassTypeAnnotations(Class<?> klass) {
2062 return klass.getRawTypeAnnotations();
2063 }
2064 public byte[] getRawExecutableTypeAnnotations(Executable executable) {
2065 return Class.getExecutableTypeAnnotationBytes(executable);
2066 }
2067 public <E extends Enum<E>>
2068 E[] getEnumConstantsShared(Class<E> klass) {
2069 return klass.getEnumConstantsShared();
2070 }
2071 public void blockedOn(Interruptible b) {
2072 Thread.blockedOn(b);
2073 }
2074 public void registerShutdownHook(int slot, boolean registerShutdownInProgress, Runnable hook) {
2075 Shutdown.add(slot, registerShutdownInProgress, hook);
2076 }
2077 public Thread newThreadWithAcc(Runnable target, AccessControlContext acc) {
2078 return new Thread(target, acc);
2079 }
2080 @SuppressWarnings("deprecation")
2081 public void invokeFinalize(Object o) throws Throwable {
2082 o.finalize();
2083 }
2084 public ConcurrentHashMap<?, ?> createOrGetClassLoaderValueMap(ClassLoader cl) {
2085 return cl.createOrGetClassLoaderValueMap();
2086 }
2087 public Class<?> defineClass(ClassLoader loader, String name, byte[] b, ProtectionDomain pd, String source) {
2088 return ClassLoader.defineClass1(loader, name, b, 0, b.length, pd, source);
2089 }
2090 public Class<?> findBootstrapClassOrNull(ClassLoader cl, String name) {
2091 return cl.findBootstrapClassOrNull(name);
2092 }
2093 public Package definePackage(ClassLoader cl, String name, Module module) {
2094 return cl.definePackage(name, module);
2095 }
2096 public String fastUUID(long lsb, long msb) {
2097 return Long.fastUUID(lsb, msb);
2098 }
2099 public void addNonExportedPackages(ModuleLayer layer) {
2100 SecurityManager.addNonExportedPackages(layer);
2101 }
2102 public void invalidatePackageAccessCache() {
2103 SecurityManager.invalidatePackageAccessCache();
2104 }
2105 public Module defineModule(ClassLoader loader,
2106 ModuleDescriptor descriptor,
2107 URI uri) {
2108 return new Module(null, loader, descriptor, uri);
2109 }
2110 public Module defineUnnamedModule(ClassLoader loader) {
2111 return new Module(loader);
2112 }
2113 public void addReads(Module m1, Module m2) {
2114 m1.implAddReads(m2);
2115 }
2116 public void addReadsAllUnnamed(Module m) {
2117 m.implAddReadsAllUnnamed();
2118 }
2119 public void addExports(Module m, String pn, Module other) {
2120 m.implAddExports(pn, other);
2121 }
2122 public void addExportsToAllUnnamed(Module m, String pn) {
2123 m.implAddExportsToAllUnnamed(pn);
2124 }
2125 public void addOpens(Module m, String pn, Module other) {
2126 m.implAddOpens(pn, other);
2127 }
2128 public void addOpensToAllUnnamed(Module m, String pn) {
2129 m.implAddOpensToAllUnnamed(pn);
2130 }
2131 public void addOpensToAllUnnamed(Module m, Iterator<String> packages) {
2132 m.implAddOpensToAllUnnamed(packages);
2133 }
2134 public void addUses(Module m, Class<?> service) {
2135 m.implAddUses(service);
2136 }
2137 public boolean isReflectivelyExported(Module m, String pn, Module other) {
2138 return m.isReflectivelyExported(pn, other);
2139 }
2140 public boolean isReflectivelyOpened(Module m, String pn, Module other) {
2141 return m.isReflectivelyOpened(pn, other);
2142 }
2143 public ServicesCatalog getServicesCatalog(ModuleLayer layer) {
2144 return layer.getServicesCatalog();
2145 }
2146 public Stream<ModuleLayer> layers(ModuleLayer layer) {
2147 return layer.layers();
2148 }
2149 public Stream<ModuleLayer> layers(ClassLoader loader) {
2150 return ModuleLayer.layers(loader);
2151 }
2152
2153 public String newStringUTF8NoRepl(byte[] bytes, int off, int len) {
2154 return StringCoding.newStringUTF8NoRepl(bytes, off, len);
2155 }
2156
2157 public byte[] getBytesUTF8NoRepl(String s) {
2158 return StringCoding.getBytesUTF8NoRepl(s);
2159 }
2160
2161 });
2162 }
2163 }