- 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.*;
-
- /**
- * 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 1.1.1.1 2001/10/29 19:59:58 jvanzyl Exp $
- * @author <A HREF="mailto:markus.dahm@berlin.de">M. Dahm</A>
- */
- public abstract class Constant implements Cloneable, Node {
- /* 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(Visitor 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();
- }
-
- /**
- * Read one constant from the given file, the type depends on a tag byte.
- *
- * @param file Input stream
- * @return Constant object
- */
- static final Constant readConstant(DataInputStream file)
- throws IOException, ClassFormatError
- {
- byte b = file.readByte(); // Read tag byte
-
- switch(b) {
- case Constants.CONSTANT_Class: return new ConstantClass(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);
- case Constants.CONSTANT_NameAndType: return new ConstantNameAndType(file);
- case Constants.CONSTANT_Utf8: return new ConstantUtf8(file);
- default:
- throw new ClassFormatError("Invalid byte tag in constant pool: " + b);
- }
- }
- }