Java tutorial
package org.aspectj.apache.bcel.classfile; /* ==================================================================== * The Apache Software License, Version 1.1 * * Copyright (c) 2001 The Apache Software Foundation. All rights * reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * * 3. The end-user documentation included with the redistribution, * if any, must include the following acknowledgment: * "This product includes software developed by the * Apache Software Foundation (http://www.apache.org/)." * Alternately, this acknowledgment may appear in the software itself, * if and wherever such third-party acknowledgments normally appear. * * 4. The names "Apache" and "Apache Software Foundation" and * "Apache BCEL" must not be used to endorse or promote products * derived from this software without prior written permission. For * written permission, please contact apache@apache.org. * * 5. Products derived from this software may not be called "Apache", * "Apache BCEL", nor may "Apache" appear in their name, without * prior written permission of the Apache Software Foundation. * * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * ==================================================================== * * This software consists of voluntary contributions made by many * individuals on behalf of the Apache Software Foundation. For more * information on the Apache Software Foundation, please see * <http://www.apache.org/>. */ import java.io.DataInputStream; import java.io.DataOutputStream; import java.io.IOException; import java.io.Serializable; import org.aspectj.apache.bcel.Constants; import org.aspectj.apache.bcel.classfile.annotation.RuntimeInvisAnnos; import org.aspectj.apache.bcel.classfile.annotation.RuntimeInvisParamAnnos; import org.aspectj.apache.bcel.classfile.annotation.RuntimeInvisTypeAnnos; import org.aspectj.apache.bcel.classfile.annotation.RuntimeVisAnnos; import org.aspectj.apache.bcel.classfile.annotation.RuntimeVisParamAnnos; import org.aspectj.apache.bcel.classfile.annotation.RuntimeVisTypeAnnos; /** * Abstract super class for <em>Attribute</em> objects. Currently the <em>ConstantValue</em>, <em>SourceFile</em>, <em>Code</em>, * <em>Exceptiontable</em>, <em>LineNumberTable</em>, <em>LocalVariableTable</em>, <em>InnerClasses</em> and <em>Synthetic</em> * attributes are supported. The <em>Unknown</em> attribute stands for non-standard-attributes. * * @version $Id: Attribute.java,v 1.9 2009/12/09 18:01:31 aclement Exp $ * @author <A HREF="mailto:markus.dahm@berlin.de">M. Dahm</A> * @see ConstantValue * @see SourceFile * @see Code * @see Unknown * @see ExceptionTable * @see LineNumberTable * @see LocalVariableTable * @see InnerClasses * @see Synthetic * @see Deprecated * @see Signature */ public abstract class Attribute implements Cloneable, Node, Serializable { public final static Attribute[] NoAttributes = new Attribute[0]; protected byte tag; // Tag to distinguish subclasses protected int nameIndex; protected int length; protected ConstantPool cpool; protected Attribute(byte tag, int nameIndex, int length, ConstantPool cpool) { this.tag = tag; this.nameIndex = nameIndex; this.length = length; this.cpool = cpool; } public void dump(DataOutputStream file) throws IOException { file.writeShort(nameIndex); file.writeInt(length); } // OPTIMIZE how about just reading them in and storing them until we need to decode what they really are? public static final Attribute readAttribute(DataInputStream file, ConstantPool cpool) throws IOException { byte tag = Constants.ATTR_UNKNOWN; int idx = file.readUnsignedShort(); String name = cpool.getConstantUtf8(idx).getValue(); int len = file.readInt(); // Compare strings to find known attribute for (byte i = 0; i < Constants.KNOWN_ATTRIBUTES; i++) { if (name.equals(Constants.ATTRIBUTE_NAMES[i])) { tag = i; break; } } switch (tag) { case Constants.ATTR_UNKNOWN: return new Unknown(idx, len, file, cpool); case Constants.ATTR_CONSTANT_VALUE: return new ConstantValue(idx, len, file, cpool); case Constants.ATTR_SOURCE_FILE: return new SourceFile(idx, len, file, cpool); case Constants.ATTR_CODE: return new Code(idx, len, file, cpool); case Constants.ATTR_EXCEPTIONS: return new ExceptionTable(idx, len, file, cpool); case Constants.ATTR_LINE_NUMBER_TABLE: return new LineNumberTable(idx, len, file, cpool); case Constants.ATTR_LOCAL_VARIABLE_TABLE: return new LocalVariableTable(idx, len, file, cpool); case Constants.ATTR_INNER_CLASSES: return new InnerClasses(idx, len, file, cpool); case Constants.ATTR_SYNTHETIC: return new Synthetic(idx, len, file, cpool); case Constants.ATTR_DEPRECATED: return new Deprecated(idx, len, file, cpool); case Constants.ATTR_SIGNATURE: return new Signature(idx, len, file, cpool); case Constants.ATTR_STACK_MAP: return new StackMap(idx, len, file, cpool); case Constants.ATTR_RUNTIME_VISIBLE_ANNOTATIONS: return new RuntimeVisAnnos(idx, len, file, cpool); case Constants.ATTR_RUNTIME_INVISIBLE_ANNOTATIONS: return new RuntimeInvisAnnos(idx, len, file, cpool); case Constants.ATTR_RUNTIME_VISIBLE_PARAMETER_ANNOTATIONS: return new RuntimeVisParamAnnos(idx, len, file, cpool); case Constants.ATTR_RUNTIME_INVISIBLE_PARAMETER_ANNOTATIONS: return new RuntimeInvisParamAnnos(idx, len, file, cpool); case Constants.ATTR_ANNOTATION_DEFAULT: return new AnnotationDefault(idx, len, file, cpool); case Constants.ATTR_LOCAL_VARIABLE_TYPE_TABLE: return new LocalVariableTypeTable(idx, len, file, cpool); case Constants.ATTR_ENCLOSING_METHOD: return new EnclosingMethod(idx, len, file, cpool); case Constants.ATTR_BOOTSTRAPMETHODS: return new BootstrapMethods(idx, len, file, cpool); case Constants.ATTR_RUNTIME_VISIBLE_TYPE_ANNOTATIONS: return new RuntimeVisTypeAnnos(idx, len, file, cpool); case Constants.ATTR_RUNTIME_INVISIBLE_TYPE_ANNOTATIONS: return new RuntimeInvisTypeAnnos(idx, len, file, cpool); case Constants.ATTR_METHOD_PARAMETERS: return new MethodParameters(idx, len, file, cpool); case Constants.ATTR_MODULE: return new Module(idx, len, file, cpool); case Constants.ATTR_MODULE_PACKAGES: return new ModulePackages(idx, len, file, cpool); case Constants.ATTR_MODULE_MAIN_CLASS: return new ModuleMainClass(idx, len, file, cpool); case Constants.ATTR_NEST_HOST: return new NestHost(idx, len, file, cpool); case Constants.ATTR_NEST_MEMBERS: return new NestMembers(idx, len, file, cpool); default: throw new IllegalStateException(); } } public String getName() { return cpool.getConstantUtf8(nameIndex).getValue(); } public final int getLength() { return length; } public final int getNameIndex() { return nameIndex; } public final byte getTag() { return tag; } public final ConstantPool getConstantPool() { return cpool; } @Override public String toString() { return Constants.ATTRIBUTE_NAMES[tag]; } @Override public abstract void accept(ClassVisitor v); }