package com.sun.org.apache.bcel.internal.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 com.sun.org.apache.bcel.internal.Constants;
import java.io.*;
/**
* This class is derived from <em>Attribute</em> and represents a constant
* value, i.e., a default value for initializing a class field.
* This class is instantiated by the <em>Attribute.readAttribute()</em> method.
*
* @version $Id: ConstantValue.java,v 1.1.1.1 2001/10/29 20:00:00 jvanzyl Exp $
* @author <A HREF="mailto:markus.dahm@berlin.de">M. Dahm</A>
* @see Attribute
*/
public final class ConstantValue extends Attribute {
private int constantvalue_index;
/**
* Initialize from another object. Note that both objects use the same
* references (shallow copy). Use clone() for a physical copy.
*/
public ConstantValue(ConstantValue c) {
this(c.getNameIndex(), c.getLength(), c.getConstantValueIndex(),
c.getConstantPool());
}
/**
* Construct object from file stream.
* @param name_index Name index in constant pool
* @param length Content length in bytes
* @param file Input stream
* @param constant_pool Array of constants
* @throw IOException
*/
ConstantValue(int name_index, int length, DataInputStream file,
ConstantPool constant_pool) throws IOException
{
this(name_index, length, (int)file.readUnsignedShort(), constant_pool);
}
/**
* @param name_index Name index in constant pool
* @param length Content length in bytes
* @param constantvalue_index Index in constant pool
* @param constant_pool Array of constants
*/
public ConstantValue(int name_index, int length,
int constantvalue_index,
ConstantPool constant_pool)
{
super(Constants.ATTR_CONSTANT_VALUE, name_index, length, constant_pool);
this.constantvalue_index = constantvalue_index;
}
/**
* 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(Visitor v) {
v.visitConstantValue(this);
}
/**
* Dump constant value attribute to file stream on binary format.
*
* @param file Output file stream
* @throw IOException
*/
public final void dump(DataOutputStream file) throws IOException
{
super.dump(file);
file.writeShort(constantvalue_index);
}
/**
* @return Index in constant pool of constant value.
*/
public final int getConstantValueIndex() { return constantvalue_index; }
/**
* @param constantvalue_index.
*/
public final void setConstantValueIndex(int constantvalue_index) {
this.constantvalue_index = constantvalue_index;
}
/**
* @return String representation of constant value.
*/
public final String toString() throws InternalError
{
Constant c = constant_pool.getConstant(constantvalue_index);
String buf;
int i;
// Print constant to string depending on its type
switch(c.getTag()) {
case Constants.CONSTANT_Long: buf = "" + ((ConstantLong)c).getBytes(); break;
case Constants.CONSTANT_Float: buf = "" + ((ConstantFloat)c).getBytes(); break;
case Constants.CONSTANT_Double: buf = "" + ((ConstantDouble)c).getBytes(); break;
case Constants.CONSTANT_Integer: buf = "" + ((ConstantInteger)c).getBytes(); break;
case Constants.CONSTANT_String:
i = ((ConstantString)c).getStringIndex();
c = constant_pool.getConstant(i, Constants.CONSTANT_Utf8);
buf = "\"" + convertString(((ConstantUtf8)c).getBytes()) + "\"";
break;
default: throw new InternalError("Type of ConstValue invalid: " + c);
}
return buf;
}
/**
* Escape all occurences of newline chars '\n', quotes \", etc.
*/
private static final String convertString(String label) {
char[] ch = label.toCharArray();
StringBuffer buf = new StringBuffer();
for(int i=0; i < ch.length; i++) {
switch(ch[i]) {
case '\n':
buf.append("\\n"); break;
case '\r':
buf.append("\\r"); break;
case '\"':
buf.append("\\\""); break;
case '\'':
buf.append("\\'"); break;
case '\\':
buf.append("\\\\"); break;
default:
buf.append(ch[i]); break;
}
}
return buf.toString();
}
/**
* @return deep copy of this attribute
*/
public Attribute copy(ConstantPool constant_pool) {
ConstantValue c = (ConstantValue)clone();
c.constant_pool = constant_pool;
return c;
}
}
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