1 /*
2 * Copyright (c) 2003, 2015, 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
26 package sun.reflect;
27
28 import java.lang.reflect.*;
29
30 /** Provides reflective access to the constant pools of classes.
31 Currently this is needed to provide reflective access to annotations
32 but may be used by other internal subsystems in the future. */
33
34 public class ConstantPool {
35 // Number of entries in this constant pool (= maximum valid constant pool index)
36 public int getSize() { return getSize0 (constantPoolOop); }
37 public Class<?> getClassAt (int index) { return getClassAt0 (constantPoolOop, index); }
38 public Class<?> getClassAtIfLoaded (int index) { return getClassAtIfLoaded0 (constantPoolOop, index); }
39 // Returns a class reference index for a method or a field.
40 public int getClassRefIndexAt(int index) {
41 return getClassRefIndexAt0(constantPoolOop, index);
42 }
43 // Returns either a Method or Constructor.
44 // Static initializers are returned as Method objects.
45 public Member getMethodAt (int index) { return getMethodAt0 (constantPoolOop, index); }
46 public Member getMethodAtIfLoaded(int index) { return getMethodAtIfLoaded0(constantPoolOop, index); }
47 public Field getFieldAt (int index) { return getFieldAt0 (constantPoolOop, index); }
48 public Field getFieldAtIfLoaded (int index) { return getFieldAtIfLoaded0 (constantPoolOop, index); }
49 // Fetches the class name, member (field, method or interface
50 // method) name, and type descriptor as an array of three Strings
51 public String[] getMemberRefInfoAt (int index) { return getMemberRefInfoAt0 (constantPoolOop, index); }
52 // Returns a name and type reference index for a method, a field or an invokedynamic.
53 public int getNameAndTypeRefIndexAt(int index) {
54 return getNameAndTypeRefIndexAt0(constantPoolOop, index);
55 }
56 // Fetches the name and type from name_and_type index as an array of two Strings
57 public String[] getNameAndTypeRefInfoAt(int index) {
58 return getNameAndTypeRefInfoAt0(constantPoolOop, index);
59 }
60 public int getIntAt (int index) { return getIntAt0 (constantPoolOop, index); }
61 public long getLongAt (int index) { return getLongAt0 (constantPoolOop, index); }
62 public float getFloatAt (int index) { return getFloatAt0 (constantPoolOop, index); }
63 public double getDoubleAt (int index) { return getDoubleAt0 (constantPoolOop, index); }
64 public String getStringAt (int index) { return getStringAt0 (constantPoolOop, index); }
65 public String getUTF8At (int index) { return getUTF8At0 (constantPoolOop, index); }
66 public Tag getTagAt(int index) {
67 return Tag.valueOf(getTagAt0(constantPoolOop, index));
68 }
69
70 public static enum Tag {
71 UTF8,
72 INTEGER,
73 FLOAT,
74 LONG,
75 DOUBLE,
76 CLASS,
77 STRING,
78 FIELDREF,
79 METHODREF,
80 INTERFACEMETHODREF,
81 NAMEANDTYPE,
82 METHODHANDLE,
83 METHODTYPE,
84 INVOKEDYNAMIC,
85 INVALID;
86
87 private static Tag valueOf(byte v) {
88 switch (v) {
89 case 0: return INVALID;
90 case 1: return UTF8;
91 case 3: return INTEGER;
92 case 4: return FLOAT;
93 case 5: return LONG;
94 case 6: return DOUBLE;
95 case 7: return CLASS;
96 case 8: return STRING;
97 case 9: return FIELDREF;
98 case 10: return METHODREF;
99 case 11: return INTERFACEMETHODREF;
100 case 12: return NAMEANDTYPE;
101 case 15: return METHODHANDLE;
102 case 16: return METHODTYPE;
103 case 18: return INVOKEDYNAMIC;
104 default:
105 throw new IllegalArgumentException("Unknown constant pool tag " + v);
106 }
107 }
108 }
109 //---------------------------------------------------------------------------
110 // Internals only below this point
111 //
112
113 static {
114 Reflection.registerFieldsToFilter(ConstantPool.class, new String[] { "constantPoolOop" });
115 }
116
117 // HotSpot-internal constant pool object (set by the VM, name known to the VM)
118 private Object constantPoolOop;
119
120 private native int getSize0 (Object constantPoolOop);
121 private native Class<?> getClassAt0 (Object constantPoolOop, int index);
122 private native Class<?> getClassAtIfLoaded0 (Object constantPoolOop, int index);
123 private native int getClassRefIndexAt0 (Object constantPoolOop, int index);
124 private native Member getMethodAt0 (Object constantPoolOop, int index);
125 private native Member getMethodAtIfLoaded0(Object constantPoolOop, int index);
126 private native Field getFieldAt0 (Object constantPoolOop, int index);
127 private native Field getFieldAtIfLoaded0 (Object constantPoolOop, int index);
128 private native String[] getMemberRefInfoAt0 (Object constantPoolOop, int index);
129 private native int getNameAndTypeRefIndexAt0(Object constantPoolOop, int index);
130 private native String[] getNameAndTypeRefInfoAt0(Object constantPoolOop, int index);
131 private native int getIntAt0 (Object constantPoolOop, int index);
132 private native long getLongAt0 (Object constantPoolOop, int index);
133 private native float getFloatAt0 (Object constantPoolOop, int index);
134 private native double getDoubleAt0 (Object constantPoolOop, int index);
135 private native String getStringAt0 (Object constantPoolOop, int index);
136 private native String getUTF8At0 (Object constantPoolOop, int index);
137 private native byte getTagAt0 (Object constantPoolOop, int index);
138 }