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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 org.aspectj.apache.bcel.Constants;
import java.io.*;
/**
* Abstract superclass for classes to represent the different constant types
* in the constant pool of a class file. The classes keep closely to
* the JVM specification.
*
* @version $Id: Constant.java,v 1.3 2008/05/28 23:53:01 aclement Exp $
* @author <A HREF="mailto:markus.dahm@berlin.de">M. Dahm</A>
*/
public abstract class Constant implements Cloneable, Node, Serializable {
/* In fact this tag is redundant since we can distinguish different
* `Constant' objects by their type, i.e., via `instanceof'. In some
* places we will use the tag for switch()es anyway.
*
* First, we want match the specification as closely as possible. Second we
* need the tag as an index to select the corresponding class name from the
* `CONSTANT_NAMES' array.
*/
protected byte tag;
Constant(byte tag) { this.tag = tag; }
/**
* 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 abstract void accept(ClassVisitor v);
public abstract void dump(DataOutputStream file) throws IOException;
/**
* @return Tag of constant, i.e., its type. No setTag() method to avoid
* confusion.
*/
public final byte getTag() { return tag; }
/**
* @return String representation.
*/
public String toString() {
return Constants.CONSTANT_NAMES[tag] + "[" + tag + "]";
}
/**
* @return deep copy of this constant
*/
public Constant copy() {
try {
return (Constant)super.clone();
} catch(CloneNotSupportedException e) {}
return null;
}
public Object clone() throws CloneNotSupportedException {
return super.clone();
}
static final Constant readConstant(DataInputStream file) throws IOException, ClassFormatException {
byte b = file.readByte();
switch(b) {
case Constants.CONSTANT_Class: return new ConstantClass(file);
case Constants.CONSTANT_NameAndType: return new ConstantNameAndType(file);
case Constants.CONSTANT_Utf8: return new ConstantUtf8(file);
case Constants.CONSTANT_Fieldref: return new ConstantFieldref(file);
case Constants.CONSTANT_Methodref: return new ConstantMethodref(file);
case Constants.CONSTANT_InterfaceMethodref: return new ConstantInterfaceMethodref(file);
case Constants.CONSTANT_String: return new ConstantString(file);
case Constants.CONSTANT_Integer: return new ConstantInteger(file);
case Constants.CONSTANT_Float: return new ConstantFloat(file);
case Constants.CONSTANT_Long: return new ConstantLong(file);
case Constants.CONSTANT_Double: return new ConstantDouble(file);
default:
throw new ClassFormatException("Invalid byte tag in constant pool: " + b);
}
}
}
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