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
26 package java.lang;
27
28 import jdk.internal.loader.BuiltinClassLoader;
29 import jdk.internal.misc.SharedSecrets;
30 import jdk.internal.misc.VM;
31 import jdk.internal.module.ModuleHashes;
32
33 import java.lang.module.ModuleDescriptor.Version;
34 import java.lang.reflect.Layer;
35 import java.lang.reflect.Module;
36 import java.util.HashSet;
37 import java.util.Objects;
38 import java.util.Optional;
39 import java.util.Set;
40
41 /**
42 * An element in a stack trace, as returned by {@link
43 * Throwable#getStackTrace()}. Each element represents a single stack frame.
44 * All stack frames except for the one at the top of the stack represent
45 * a method invocation. The frame at the top of the stack represents the
46 * execution point at which the stack trace was generated. Typically,
47 * this is the point at which the throwable corresponding to the stack trace
48 * was created.
49 *
50 * @since 1.4
51 * @author Josh Bloch
52 */
53 public final class StackTraceElement implements java.io.Serializable {
54 // This field is set to the compacted String representation used
55 // by StackTraceElement::toString and stored in serial form.
56 //
57 // This field is of Object type. VM initially sets this field to
58 // the Class object of the declaring class to build the compacted string.
59 private Object classOrLoaderModuleClassName;
60
61 // Normally initialized by VM
62 private String classLoaderName;
63 private String moduleName;
64 private String moduleVersion;
65 private String declaringClass;
66 private String methodName;
67 private String fileName;
68 private int lineNumber;
69
70 /**
71 * Creates a stack trace element representing the specified execution
72 * point. The {@link #getModuleName module name} and {@link
73 * #getModuleVersion module version} of the stack trace element will
74 * be {@code null}.
75 *
76 * @param declaringClass the fully qualified name of the class containing
77 * the execution point represented by the stack trace element
78 * @param methodName the name of the method containing the execution point
79 * represented by the stack trace element
80 * @param fileName the name of the file containing the execution point
81 * represented by the stack trace element, or {@code null} if
82 * this information is unavailable
83 * @param lineNumber the line number of the source line containing the
84 * execution point represented by this stack trace element, or
85 * a negative number if this information is unavailable. A value
86 * of -2 indicates that the method containing the execution point
87 * is a native method
88 * @throws NullPointerException if {@code declaringClass} or
239 *
240 * @return the name of the method containing the execution point
241 * represented by this stack trace element.
242 */
243 public String getMethodName() {
244 return methodName;
245 }
246
247 /**
248 * Returns true if the method containing the execution point
249 * represented by this stack trace element is a native method.
250 *
251 * @return {@code true} if the method containing the execution point
252 * represented by this stack trace element is a native method.
253 */
254 public boolean isNativeMethod() {
255 return lineNumber == -2;
256 }
257
258 /**
259 * Returns a string representation of this stack trace element. The
260 * format of this string depends on the implementation, but the following
261 * examples may be regarded as typical:
262 * <ul>
263 * <li>
264 * "{@code com.foo.loader/foo@9.0/com.foo.Main.run(Main.java:101)}"
265 * - See the description below.
266 * </li>
267 * <li>
268 * "{@code com.foo.loader/foo@9.0/com.foo.Main.run(Main.java)}"
269 * - The line number is unavailable.
270 * </li>
271 * <li>
272 * "{@code com.foo.loader/foo@9.0/com.foo.Main.run(Unknown Source)}"
273 * - Neither the file name nor the line number is available.
274 * </li>
275 * <li>
276 * "{@code com.foo.loader/foo@9.0/com.foo.Main.run(Native Method)}"
277 * - The method containing the execution point is a native method.
278 * </li>
279 * <li>
280 * "{@code com.foo.loader//com.foo.bar.App.run(App.java:12)}"
281 * - The class of the execution point is defined in the unnamed module of
292 * </li>
293 * </ul>
294 *
295 * <p> The first example shows a stack trace element consisting of
296 * three elements, each separated by {@code "/"} followed with
297 * the source file name and the line number of the source line
298 * containing the execution point.
299 *
300 * The first element "{@code com.foo.loader}" is
301 * the name of the class loader. The second element "{@code foo@9.0}"
302 * is the module name and version. The third element is the method
303 * containing the execution point; "{@code com.foo.Main"}" is the
304 * fully-qualified class name and "{@code run}" is the name of the method.
305 * "{@code Main.java}" is the source file name and "{@code 101}" is
306 * the line number.
307 *
308 * <p> If a class is defined in an <em>unnamed module</em>
309 * then the second element is omitted as shown in
310 * "{@code com.foo.loader//com.foo.bar.App.run(App.java:12)}".
311 *
312 * If the class loader is a <a href="ClassLoader.html#builtinLoaders">
313 * built-in class loader</a> or is not named then the first element
314 * and its following {@code "/"} are omitted as shown in
315 * "{@code acme@2.1/org.acme.Lib.test(Lib.java:80)}".
316 * If the first element is omitted and the module is an unnamed module,
317 * the second element and its following {@code "/"} are also omitted
318 * as shown in "{@code MyClass.mash(MyClass.java:9)}".
319 *
320 * @see Throwable#printStackTrace()
321 */
322 public String toString() {
323 String s = buildLoaderModuleClassName();
324 if (s == null) {
325 // all elements will be included
326 s = "";
327 if (classLoaderName != null && !classLoaderName.isEmpty()) {
328 s += classLoaderName + "/";
329 }
330 if (moduleName != null && !moduleName.isEmpty()) {
331 s += moduleName;
332
333 if (moduleVersion != null && !moduleVersion.isEmpty()) {
334 s += "@" + moduleVersion;
335 }
336 }
337 s = s.isEmpty() ? declaringClass : s + "/" + declaringClass;
338 }
339
340 return s + "." + methodName + "(" +
341 (isNativeMethod() ? "Native Method)" :
342 (fileName != null && lineNumber >= 0 ?
343 fileName + ":" + lineNumber + ")" :
344 (fileName != null ? ""+fileName+")" : "Unknown Source)")));
345 }
346
347 /**
348 * Returns true if the specified object is another
349 * {@code StackTraceElement} instance representing the same execution
350 * point as this instance. Two stack trace elements {@code a} and
351 * {@code b} are equal if and only if:
352 * <pre>{@code
353 * equals(a.getClassLoaderName(), b.getClassLoaderName()) &&
354 * equals(a.getModuleName(), b.getModuleName()) &&
355 * equals(a.getModuleVersion(), b.getModuleVersion()) &&
356 * equals(a.getClassName(), b.getClassName()) &&
357 * equals(a.getMethodName(), b.getMethodName())
358 * equals(a.getFileName(), b.getFileName()) &&
380 e.lineNumber == lineNumber &&
381 Objects.equals(methodName, e.methodName) &&
382 Objects.equals(fileName, e.fileName);
383 }
384
385 /**
386 * Returns a hash code value for this stack trace element.
387 */
388 public int hashCode() {
389 int result = 31*declaringClass.hashCode() + methodName.hashCode();
390 result = 31*result + Objects.hashCode(classLoaderName);
391 result = 31*result + Objects.hashCode(moduleName);
392 result = 31*result + Objects.hashCode(moduleVersion);
393 result = 31*result + Objects.hashCode(fileName);
394 result = 31*result + lineNumber;
395 return result;
396 }
397
398
399 /**
400 * Build the compacted String representation to be returned by
401 * toString method from the declaring Class object.
402 */
403 synchronized String buildLoaderModuleClassName() {
404 if (classOrLoaderModuleClassName == null)
405 return null;
406
407 if (classOrLoaderModuleClassName instanceof Class) {
408 Class<?> cls = (Class<?>)classOrLoaderModuleClassName;
409 classOrLoaderModuleClassName = toLoaderModuleClassName(cls);
410 }
411 return (String)classOrLoaderModuleClassName;
412 }
413
414 /**
415 * Returns <loader>/<module>/<fully-qualified-classname> string
416 * representation of the given class.
417 * <p>
418 * If the module is a non-upgradeable JDK module then omit
419 * its version string.
420 * <p>
421 * If the loader has no name, or if the loader is one of the built-in
422 * loaders (`boot`, `platform`, or `app`) then drop the first element
423 * (`<loader>/`).
424 * <p>
425 * If the first element has been dropped and the module is unnamed
426 * then drop the second element (`<module>/`).
427 * <p>
428 * If the first element is not dropped and the module is unnamed
429 * then drop `<module>`.
430 */
431 private static String toLoaderModuleClassName(Class<?> cls) {
432 ClassLoader loader = cls.getClassLoader0();
433 Module m = cls.getModule();
434
435 // First element - class loader name
436 // Call package-private ClassLoader::name method
437 String s = "";
438 if (loader != null && loader.name() != null &&
439 !(loader instanceof BuiltinClassLoader)) {
440 s = loader.name() + "/";
441 }
442
443 // Second element - module name and version
444 if (m != null && m.isNamed()) {
445 s += m.getName();
446 // Include version if it is a user module or upgradeable module
447 //
448 // If it is JDK non-upgradeable module which is recorded
449 // in the hashes in java.base, omit the version.
450 if (!isHashedInJavaBase(m)) {
451 Optional<Version> ov = m.getDescriptor().version();
452 if (ov.isPresent()) {
453 String version = "@" + ov.get().toString();
454 s += version;
455 }
456 }
457 }
458
459 // fully-qualified class name
460 return s.isEmpty() ? cls.getName() : s + "/" + cls.getName();
461 }
462
463 /**
464 * Returns true if the module is hashed with java.base.
465 * <p>
466 * This method returns false when running on the exploded image
467 * since JDK modules are not hashed. They have no Version attribute
468 * and so "@<version>" part will be omitted anyway.
469 */
470 private static boolean isHashedInJavaBase(Module m) {
471 // return true if module system is not initialized as the code
472 // must be in java.base
473 if (!VM.isModuleSystemInited())
474 return true;
475
476 return Layer.boot() == m.getLayer() && HashedModules.contains(m);
477 }
478
479 /*
480 * Finds JDK non-upgradeable modules, i.e. the modules that are
502 return HASHED_MODULES.contains(m.getName());
503 }
504 }
505
506
507 /*
508 * Returns an array of StackTraceElements of the given depth
509 * filled from the backtrace of a given Throwable.
510 */
511 static StackTraceElement[] of(Throwable x, int depth) {
512 StackTraceElement[] stackTrace = new StackTraceElement[depth];
513 for (int i = 0; i < depth; i++) {
514 stackTrace[i] = new StackTraceElement();
515 }
516
517 // VM to fill in StackTraceElement
518 initStackTraceElements(stackTrace, x);
519
520 // ensure the proper StackTraceElement initialization
521 for (StackTraceElement ste : stackTrace) {
522 ste.buildLoaderModuleClassName();
523 }
524 return stackTrace;
525 }
526
527 /*
528 * Returns a StackTraceElement from a given StackFrameInfo.
529 */
530 static StackTraceElement of(StackFrameInfo sfi) {
531 StackTraceElement ste = new StackTraceElement();
532 initStackTraceElement(ste, sfi);
533
534 ste.buildLoaderModuleClassName();
535 return ste;
536 }
537
538 /*
539 * Sets the given stack trace elements with the backtrace
540 * of the given Throwable.
541 */
542 private static native void initStackTraceElements(StackTraceElement[] elements,
543 Throwable x);
544 /*
545 * Sets the given stack trace element with the given StackFrameInfo
546 */
547 private static native void initStackTraceElement(StackTraceElement element,
548 StackFrameInfo sfi);
549
550 private static final long serialVersionUID = 6992337162326171013L;
551 }
|
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
26 package java.lang;
27
28 import jdk.internal.loader.BuiltinClassLoader;
29 import jdk.internal.misc.SharedSecrets;
30 import jdk.internal.misc.VM;
31 import jdk.internal.module.ModuleHashes;
32
33 import java.lang.reflect.Layer;
34 import java.lang.reflect.Module;
35 import java.util.HashSet;
36 import java.util.Objects;
37 import java.util.Optional;
38 import java.util.Set;
39
40 /**
41 * An element in a stack trace, as returned by {@link
42 * Throwable#getStackTrace()}. Each element represents a single stack frame.
43 * All stack frames except for the one at the top of the stack represent
44 * a method invocation. The frame at the top of the stack represents the
45 * execution point at which the stack trace was generated. Typically,
46 * this is the point at which the throwable corresponding to the stack trace
47 * was created.
48 *
49 * @since 1.4
50 * @author Josh Bloch
51 */
52 public final class StackTraceElement implements java.io.Serializable {
53
54 // For Throwables and StackWalker, the VM initially sets this field to a
55 // reference to the declaring Class. The Class reference is used to
56 // construct the 'format' bitmap, and then is cleared.
57 //
58 // For STEs constructed using the public constructors, this field is not used.
59 private transient Class<?> declaringClassObject;
60
61 // Normally initialized by VM
62 private String classLoaderName;
63 private String moduleName;
64 private String moduleVersion;
65 private String declaringClass;
66 private String methodName;
67 private String fileName;
68 private int lineNumber;
69 private byte format = 0; // Default to show all
70
71 /**
72 * Creates a stack trace element representing the specified execution
73 * point. The {@link #getModuleName module name} and {@link
74 * #getModuleVersion module version} of the stack trace element will
75 * be {@code null}.
76 *
77 * @param declaringClass the fully qualified name of the class containing
78 * the execution point represented by the stack trace element
79 * @param methodName the name of the method containing the execution point
80 * represented by the stack trace element
81 * @param fileName the name of the file containing the execution point
82 * represented by the stack trace element, or {@code null} if
83 * this information is unavailable
84 * @param lineNumber the line number of the source line containing the
85 * execution point represented by this stack trace element, or
86 * a negative number if this information is unavailable. A value
87 * of -2 indicates that the method containing the execution point
88 * is a native method
89 * @throws NullPointerException if {@code declaringClass} or
240 *
241 * @return the name of the method containing the execution point
242 * represented by this stack trace element.
243 */
244 public String getMethodName() {
245 return methodName;
246 }
247
248 /**
249 * Returns true if the method containing the execution point
250 * represented by this stack trace element is a native method.
251 *
252 * @return {@code true} if the method containing the execution point
253 * represented by this stack trace element is a native method.
254 */
255 public boolean isNativeMethod() {
256 return lineNumber == -2;
257 }
258
259 /**
260 * Returns a string representation of this stack trace element.
261 *
262 * @apiNote The format of this string depends on the implementation, but the
263 * following examples may be regarded as typical:
264 * <ul>
265 * <li>
266 * "{@code com.foo.loader/foo@9.0/com.foo.Main.run(Main.java:101)}"
267 * - See the description below.
268 * </li>
269 * <li>
270 * "{@code com.foo.loader/foo@9.0/com.foo.Main.run(Main.java)}"
271 * - The line number is unavailable.
272 * </li>
273 * <li>
274 * "{@code com.foo.loader/foo@9.0/com.foo.Main.run(Unknown Source)}"
275 * - Neither the file name nor the line number is available.
276 * </li>
277 * <li>
278 * "{@code com.foo.loader/foo@9.0/com.foo.Main.run(Native Method)}"
279 * - The method containing the execution point is a native method.
280 * </li>
281 * <li>
282 * "{@code com.foo.loader//com.foo.bar.App.run(App.java:12)}"
283 * - The class of the execution point is defined in the unnamed module of
294 * </li>
295 * </ul>
296 *
297 * <p> The first example shows a stack trace element consisting of
298 * three elements, each separated by {@code "/"} followed with
299 * the source file name and the line number of the source line
300 * containing the execution point.
301 *
302 * The first element "{@code com.foo.loader}" is
303 * the name of the class loader. The second element "{@code foo@9.0}"
304 * is the module name and version. The third element is the method
305 * containing the execution point; "{@code com.foo.Main"}" is the
306 * fully-qualified class name and "{@code run}" is the name of the method.
307 * "{@code Main.java}" is the source file name and "{@code 101}" is
308 * the line number.
309 *
310 * <p> If a class is defined in an <em>unnamed module</em>
311 * then the second element is omitted as shown in
312 * "{@code com.foo.loader//com.foo.bar.App.run(App.java:12)}".
313 *
314 * <p> If the class loader is a <a href="ClassLoader.html#builtinLoaders">
315 * built-in class loader</a> or is not named then the first element
316 * and its following {@code "/"} are omitted as shown in
317 * "{@code acme@2.1/org.acme.Lib.test(Lib.java:80)}".
318 * If the first element is omitted and the module is an unnamed module,
319 * the second element and its following {@code "/"} are also omitted
320 * as shown in "{@code MyClass.mash(MyClass.java:9)}".
321 *
322 * <p> The {@code toString} method may return two different values on two
323 * {@code StackTraceElement} instances that are
324 * {@linkplain #equals(Object) equal}, for example one created via the
325 * constructor, and one obtained from {@link java.lang.Throwable} or
326 * {@link java.lang.StackWalker.StackFrame}, where an implementation may
327 * choose to omit some element in the returned string.
328 *
329 * @see Throwable#printStackTrace()
330 */
331 public String toString() {
332 String s = "";
333 if (!dropClassLoaderName() && classLoaderName != null &&
334 !classLoaderName.isEmpty()) {
335 s += classLoaderName + "/";
336 }
337 if (moduleName != null && !moduleName.isEmpty()) {
338 s += moduleName;
339
340 if (!dropModuleVersion() && moduleVersion != null &&
341 !moduleVersion.isEmpty()) {
342 s += "@" + moduleVersion;
343 }
344 }
345 s = s.isEmpty() ? declaringClass : s + "/" + declaringClass;
346
347 return s + "." + methodName + "(" +
348 (isNativeMethod() ? "Native Method)" :
349 (fileName != null && lineNumber >= 0 ?
350 fileName + ":" + lineNumber + ")" :
351 (fileName != null ? ""+fileName+")" : "Unknown Source)")));
352 }
353
354 /**
355 * Returns true if the specified object is another
356 * {@code StackTraceElement} instance representing the same execution
357 * point as this instance. Two stack trace elements {@code a} and
358 * {@code b} are equal if and only if:
359 * <pre>{@code
360 * equals(a.getClassLoaderName(), b.getClassLoaderName()) &&
361 * equals(a.getModuleName(), b.getModuleName()) &&
362 * equals(a.getModuleVersion(), b.getModuleVersion()) &&
363 * equals(a.getClassName(), b.getClassName()) &&
364 * equals(a.getMethodName(), b.getMethodName())
365 * equals(a.getFileName(), b.getFileName()) &&
387 e.lineNumber == lineNumber &&
388 Objects.equals(methodName, e.methodName) &&
389 Objects.equals(fileName, e.fileName);
390 }
391
392 /**
393 * Returns a hash code value for this stack trace element.
394 */
395 public int hashCode() {
396 int result = 31*declaringClass.hashCode() + methodName.hashCode();
397 result = 31*result + Objects.hashCode(classLoaderName);
398 result = 31*result + Objects.hashCode(moduleName);
399 result = 31*result + Objects.hashCode(moduleVersion);
400 result = 31*result + Objects.hashCode(fileName);
401 result = 31*result + lineNumber;
402 return result;
403 }
404
405
406 /**
407 * Called from of() methods to set the 'format' bitmap using the Class
408 * reference stored in declaringClassObject, and then clear the reference.
409 *
410 * <p>
411 * If the module is a non-upgradeable JDK module, then set
412 * JDK_NON_UPGRADEABLE_MODULE to omit its version string.
413 * <p>
414 * If the loader is one of the built-in loaders (`boot`, `platform`, or `app`)
415 * then set BUILTIN_CLASS_LOADER to omit the first element (`<loader>/`).
416 */
417 private synchronized void computeFormat() {
418 try {
419 Class<?> cls = (Class<?>) declaringClassObject;
420 ClassLoader loader = cls.getClassLoader0();
421 Module m = cls.getModule();
422 byte bits = 0;
423
424 // First element - class loader name
425 // Call package-private ClassLoader::name method
426
427 if (loader instanceof BuiltinClassLoader) {
428 bits |= BUILTIN_CLASS_LOADER;
429 }
430
431 // Second element - module name and version
432
433 // Omit if is a JDK non-upgradeable module (recorded in the hashes
434 // in java.base)
435 if (isHashedInJavaBase(m)) {
436 bits |= JDK_NON_UPGRADEABLE_MODULE;
437 }
438 format = bits;
439 } finally {
440 // Class reference no longer needed, clear it
441 declaringClassObject = null;
442 }
443 }
444
445 private static final byte BUILTIN_CLASS_LOADER = 0x1;
446 private static final byte JDK_NON_UPGRADEABLE_MODULE = 0x2;
447
448 private boolean dropClassLoaderName() {
449 return (format & BUILTIN_CLASS_LOADER) == BUILTIN_CLASS_LOADER;
450 }
451
452 private boolean dropModuleVersion() {
453 return (format & JDK_NON_UPGRADEABLE_MODULE) == JDK_NON_UPGRADEABLE_MODULE;
454 }
455
456 /**
457 * Returns true if the module is hashed with java.base.
458 * <p>
459 * This method returns false when running on the exploded image
460 * since JDK modules are not hashed. They have no Version attribute
461 * and so "@<version>" part will be omitted anyway.
462 */
463 private static boolean isHashedInJavaBase(Module m) {
464 // return true if module system is not initialized as the code
465 // must be in java.base
466 if (!VM.isModuleSystemInited())
467 return true;
468
469 return Layer.boot() == m.getLayer() && HashedModules.contains(m);
470 }
471
472 /*
473 * Finds JDK non-upgradeable modules, i.e. the modules that are
495 return HASHED_MODULES.contains(m.getName());
496 }
497 }
498
499
500 /*
501 * Returns an array of StackTraceElements of the given depth
502 * filled from the backtrace of a given Throwable.
503 */
504 static StackTraceElement[] of(Throwable x, int depth) {
505 StackTraceElement[] stackTrace = new StackTraceElement[depth];
506 for (int i = 0; i < depth; i++) {
507 stackTrace[i] = new StackTraceElement();
508 }
509
510 // VM to fill in StackTraceElement
511 initStackTraceElements(stackTrace, x);
512
513 // ensure the proper StackTraceElement initialization
514 for (StackTraceElement ste : stackTrace) {
515 ste.computeFormat();
516 }
517 return stackTrace;
518 }
519
520 /*
521 * Returns a StackTraceElement from a given StackFrameInfo.
522 */
523 static StackTraceElement of(StackFrameInfo sfi) {
524 StackTraceElement ste = new StackTraceElement();
525 initStackTraceElement(ste, sfi);
526
527 ste.computeFormat();
528 return ste;
529 }
530
531 /*
532 * Sets the given stack trace elements with the backtrace
533 * of the given Throwable.
534 */
535 private static native void initStackTraceElements(StackTraceElement[] elements,
536 Throwable x);
537 /*
538 * Sets the given stack trace element with the given StackFrameInfo
539 */
540 private static native void initStackTraceElement(StackTraceElement element,
541 StackFrameInfo sfi);
542
543 private static final long serialVersionUID = 6992337162326171013L;
544 }
|