1 /*
2 * Copyright (c) 2007, 2013, 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 com.sun.tools.classfile;
27
28 import java.io.File;
29 import java.io.IOException;
30 import java.io.InputStream;
31 import java.nio.file.Files;
32 import java.nio.file.Path;
33
34 import static com.sun.tools.classfile.AccessFlags.*;
35
36 /**
37 * See JVMS, section 4.2.
38 *
39 * <p><b>This is NOT part of any supported API.
40 * If you write code that depends on this, you do so at your own risk.
41 * This code and its internal interfaces are subject to change or
42 * deletion without notice.</b>
43 */
44 public class ClassFile {
45 public static ClassFile read(File file)
46 throws IOException, ConstantPoolException {
47 return read(file.toPath(), new Attribute.Factory());
48 }
49
50 public static ClassFile read(Path input)
51 throws IOException, ConstantPoolException {
52 return read(input, new Attribute.Factory());
53 }
54
55 public static ClassFile read(Path input, Attribute.Factory attributeFactory)
56 throws IOException, ConstantPoolException {
57 try (InputStream in = Files.newInputStream(input)) {
58 return new ClassFile(in, attributeFactory);
59 }
60 }
61
62 public static ClassFile read(File file, Attribute.Factory attributeFactory)
63 throws IOException, ConstantPoolException {
64 return read(file.toPath(), attributeFactory);
65 }
66
67 public static ClassFile read(InputStream in)
68 throws IOException, ConstantPoolException {
69 return new ClassFile(in, new Attribute.Factory());
70 }
71
72 public static ClassFile read(InputStream in, Attribute.Factory attributeFactory)
73 throws IOException, ConstantPoolException {
74 return new ClassFile(in, attributeFactory);
75 }
76
77 ClassFile(InputStream in, Attribute.Factory attributeFactory) throws IOException, ConstantPoolException {
78 ClassReader cr = new ClassReader(this, in, attributeFactory);
79 magic = cr.readInt();
80 minor_version = cr.readUnsignedShort();
81 major_version = cr.readUnsignedShort();
82 constant_pool = new ConstantPool(cr);
83 access_flags = new AccessFlags(cr);
84 this_class = cr.readUnsignedShort();
85 super_class = cr.readUnsignedShort();
86
87 int interfaces_count = cr.readUnsignedShort();
88 interfaces = new int[interfaces_count];
89 for (int i = 0; i < interfaces_count; i++)
90 interfaces[i] = cr.readUnsignedShort();
91
92 int fields_count = cr.readUnsignedShort();
93 fields = new Field[fields_count];
94 for (int i = 0; i < fields_count; i++)
95 fields[i] = new Field(cr);
96
97 int methods_count = cr.readUnsignedShort();
98 methods = new Method[methods_count];
99 for (int i = 0; i < methods_count; i++)
100 methods[i] = new Method(cr);
101
102 attributes = new Attributes(cr);
103 }
104
105 public ClassFile(int magic, int minor_version, int major_version,
106 ConstantPool constant_pool, AccessFlags access_flags,
107 int this_class, int super_class, int[] interfaces,
108 Field[] fields, Method[] methods, Attributes attributes) {
109 this.magic = magic;
110 this.minor_version = minor_version;
111 this.major_version = major_version;
112 this.constant_pool = constant_pool;
113 this.access_flags = access_flags;
114 this.this_class = this_class;
115 this.super_class = super_class;
116 this.interfaces = interfaces;
117 this.fields = fields;
118 this.methods = methods;
119 this.attributes = attributes;
120 }
121
122 public String getName() throws ConstantPoolException {
123 return constant_pool.getClassInfo(this_class).getName();
124 }
125
126 public String getSuperclassName() throws ConstantPoolException {
127 return constant_pool.getClassInfo(super_class).getName();
128 }
129
130 public String getInterfaceName(int i) throws ConstantPoolException {
131 return constant_pool.getClassInfo(interfaces[i]).getName();
132 }
133
134 public Attribute getAttribute(String name) {
135 return attributes.get(name);
136 }
137
138 public boolean isClass() {
139 return !isInterface();
140 }
141
142 public boolean isInterface() {
143 return access_flags.is(ACC_INTERFACE);
144 }
145
146 public int byteLength() {
147 return 4 + // magic
148 2 + // minor
149 2 + // major
150 constant_pool.byteLength() +
151 2 + // access flags
152 2 + // this_class
153 2 + // super_class
154 byteLength(interfaces) +
155 byteLength(fields) +
156 byteLength(methods) +
157 attributes.byteLength();
158 }
159
160 private int byteLength(int[] indices) {
161 return 2 + 2 * indices.length;
162 }
163
164 private int byteLength(Field[] fields) {
165 int length = 2;
166 for (Field f: fields)
167 length += f.byteLength();
168 return length;
169 }
170
171 private int byteLength(Method[] methods) {
172 int length = 2;
173 for (Method m: methods)
174 length += m.byteLength();
175 return length;
176 }
177
178 public final int magic;
179 public final int minor_version;
180 public final int major_version;
181 public final ConstantPool constant_pool;
182 public final AccessFlags access_flags;
183 public final int this_class;
184 public final int super_class;
185 public final int[] interfaces;
186 public final Field[] fields;
187 public final Method[] methods;
188 public final Attributes attributes;
189 }