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. 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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 org.aspectj.apache.bcel.Constants; /** * This class represents a local variable within a method. It contains its scope, name, signature and index on the method's frame. * * @version $Id: LocalVariable.java,v 1.5 2009/09/10 15:35:05 aclement Exp $ * @author <A HREF="mailto:markus.dahm@berlin.de">M. Dahm</A> * @see LocalVariableTable */ public final class LocalVariable implements Constants, Cloneable, Node { private int start_pc; // Range in which the variable is valid private int length; private int name_index; // Index in constant pool of variable name private int signature_index; // Index of variable signature private int index; /* * Variable is `index'th local variable on this method's frame. */ private ConstantPool constant_pool; /** * Initialize from another object. Note that both objects use the same references (shallow copy). Use copy() for a physical * copy. */ public LocalVariable(LocalVariable c) { this(c.getStartPC(), c.getLength(), c.getNameIndex(), c.getSignatureIndex(), c.getIndex(), c.getConstantPool()); } /** * Construct object from file stream. * * @param file Input stream * @throws IOException */ LocalVariable(DataInputStream file, ConstantPool constant_pool) throws IOException { this(file.readUnsignedShort(), file.readUnsignedShort(), file.readUnsignedShort(), file.readUnsignedShort(), file.readUnsignedShort(), constant_pool); } /** * @param start_pc Range in which the variable * @param length ... is valid * @param name_index Index in constant pool of variable name * @param signature_index Index of variable's signature * @param index Variable is `index'th local variable on the method's frame * @param constant_pool Array of constants */ public LocalVariable(int start_pc, int length, int name_index, int signature_index, int index, ConstantPool constant_pool) { this.start_pc = start_pc; this.length = length; this.name_index = name_index; this.signature_index = signature_index; this.index = index; this.constant_pool = constant_pool; } /** * Called by objects that are traversing the nodes of the tree implicitely defined by the contents of a Java class. I.e., the * hierarchy of methods, fields, attributes, etc. spawns a tree of objects. * * @param v Visitor object */ public void accept(ClassVisitor v) { v.visitLocalVariable(this); } /** * Dump local variable to file stream in binary format. * * @param file Output file stream * @throws IOException */ public final void dump(DataOutputStream file) throws IOException { file.writeShort(start_pc); file.writeShort(length); file.writeShort(name_index); file.writeShort(signature_index); file.writeShort(index); } /** * @return Constant pool used by this object. */ public final ConstantPool getConstantPool() { return constant_pool; } /** * @return Variable is valid within getStartPC() .. getStartPC()+getLength() */ public final int getLength() { return length; } /** * @return Variable name. */ public final String getName() { ConstantUtf8 c; c = (ConstantUtf8) constant_pool.getConstant(name_index, CONSTANT_Utf8); return c.getValue(); } /** * @return Index in constant pool of variable name. */ public final int getNameIndex() { return name_index; } /** * @return Signature. */ public final String getSignature() { ConstantUtf8 c; c = (ConstantUtf8) constant_pool.getConstant(signature_index, CONSTANT_Utf8); return c.getValue(); } /** * @return Index in constant pool of variable signature. */ public final int getSignatureIndex() { return signature_index; } /** * @return index of register where variable is stored */ public final int getIndex() { return index; } /** * @return Start of range where he variable is valid */ public final int getStartPC() { return start_pc; } /** * @param constant_pool Constant pool to be used for this object. */ public final void setConstantPool(ConstantPool constant_pool) { this.constant_pool = constant_pool; } /** * @param length. */ public final void setLength(int length) { this.length = length; } /** * @param name_index. */ public final void setNameIndex(int name_index) { this.name_index = name_index; } /** * @param signature_index. */ public final void setSignatureIndex(int signature_index) { this.signature_index = signature_index; } /** * @param index. */ public final void setIndex(int index) { this.index = index; } /** * @param start_pc Specify range where the local variable is valid. */ public final void setStartPC(int start_pc) { this.start_pc = start_pc; } /** * @return string representation. */ @Override public final String toString() { String name = getName(), signature = Utility.signatureToString(getSignature()); return "LocalVariable(start_pc = " + start_pc + ", length = " + length + ", index = " + index + ":" + signature + " " + name + ")"; } /** * @return deep copy of this object */ public LocalVariable copy() { try { return (LocalVariable) clone(); } catch (CloneNotSupportedException e) { } return null; } }