001 /*
002 * Copyright 2007-2008 Sun Microsystems, Inc. All Rights Reserved.
003 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
004 *
005 * This code is free software; you can redistribute it and/or modify it
006 * under the terms of the GNU General Public License version 2 only, as
007 * published by the Free Software Foundation. Sun designates this
008 * particular file as subject to the "Classpath" exception as provided
009 * by Sun in the LICENSE file that accompanied this code.
010 *
011 * This code is distributed in the hope that it will be useful, but WITHOUT
012 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
013 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
014 * version 2 for more details (a copy is included in the LICENSE file that
015 * accompanied this code).
016 *
017 * You should have received a copy of the GNU General Public License version
018 * 2 along with this work; if not, write to the Free Software Foundation,
019 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
020 *
021 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
022 * CA 95054 USA or visit www.sun.com if you need additional information or
023 * have any questions.
024 */
025
026 package com.sun.tools.classfile;
027
028 import java.io.BufferedInputStream;
029 import java.io.ByteArrayInputStream;
030 import java.io.DataInputStream;
031 import java.io.IOException;
032 import java.io.InputStream;
033
034 /**
035 * <p><b>This is NOT part of any API supported by Sun Microsystems. If
036 * you write code that depends on this, you do so at your own risk.
037 * This code and its internal interfaces are subject to change or
038 * deletion without notice.</b>
039 */
040 public class ClassReader {
041 ClassReader(ClassFile classFile, InputStream in, Attribute.Factory attributeFactory) throws IOException {
042 // null checks
043 classFile.getClass();
044 attributeFactory.getClass();
045
046 this.classFile = classFile;
047 this.in = new DataInputStream(new BufferedInputStream(in));
048 this.attributeFactory = attributeFactory;
049 }
050
051 ClassFile getClassFile() {
052 return classFile;
053 }
054
055 ConstantPool getConstantPool() {
056 return classFile.constant_pool;
057 }
058
059 public Attribute readAttribute() throws IOException {
060 int name_index = readUnsignedShort();
061 int length = readInt();
062 byte[] data = new byte[length];
063 readFully(data);
064
065 DataInputStream prev = in;
066 in = new DataInputStream(new ByteArrayInputStream(data));
067 try {
068 return attributeFactory.createAttribute(this, name_index, data);
069 } finally {
070 in = prev;
071 }
072 }
073
074 public void readFully(byte[] b) throws IOException {
075 in.readFully(b);
076 }
077
078 public int readUnsignedByte() throws IOException {
079 return in.readUnsignedByte();
080 }
081
082 public int readUnsignedShort() throws IOException {
083 return in.readUnsignedShort();
084 }
085
086 public int readInt() throws IOException {
087 return in.readInt();
088 }
089
090 public long readLong() throws IOException {
091 return in.readLong();
092 }
093
094 public float readFloat() throws IOException {
095 return in.readFloat();
096 }
097
098 public double readDouble() throws IOException {
099 return in.readDouble();
100 }
101
102 public String readUTF() throws IOException {
103 return in.readUTF();
104 }
105
106 private DataInputStream in;
107 private ClassFile classFile;
108 private Attribute.Factory attributeFactory;
109 }