org.apache.tomcat.util.bcel.classfile.LocalVariable Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
package org.apache.tomcat.util.bcel.classfile;
import java.io.DataInput;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.Serializable;
import org.apache.tomcat.util.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 1057670 2011-01-11 14:52:05Z markt $
* @author M. Dahm
* @see LocalVariableTable
*/
public final class LocalVariable implements Constants, Cloneable, Serializable {
private static final long serialVersionUID = -914189896372081589L;
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;
/**
* Construct object from file stream.
* @param file Input stream
* @throws IOException
*/
LocalVariable(DataInput 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;
}
/**
* 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 Variable name.
*/
public final String getName() {
ConstantUtf8 c;
c = (ConstantUtf8) constant_pool.getConstant(name_index, CONSTANT_Utf8);
return c.getBytes();
}
/**
* @return Signature.
*/
public final String getSignature() {
ConstantUtf8 c;
c = (ConstantUtf8) constant_pool.getConstant(signature_index, CONSTANT_Utf8);
return c.getBytes();
}
/**
* @return index of register where variable is stored
*/
public final int getIndex() {
return index;
}
/**
* @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;
}
}