StringConstant.java

/*
 *   
 *
 * Copyright  1990-2009 Sun Microsystems, Inc. All Rights Reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER
 * 
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License version
 * 2 only, as published by the Free Software Foundation.
 * 
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * General Public License version 2 for more details (a copy is
 * included at /legal/license.txt).
 * 
 * You should have received a copy of the GNU General Public License
 * version 2 along with this work; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA
 * 
 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa
 * Clara, CA 95054 or visit www.sun.com if you need additional
 * information or have any questions.
 */

package components;
import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;
import util.DataFormatException;

// Represents a CONSTANT_String.  These constants are somewhat
// complicated in that we must fake string bodies for them.

public
class StringConstant extends ConstantObject
{
    // Filled in by Clas.resolveConstants()
    public UnicodeConstant str;

    public int strIndex;	// unresolved index of UnicodeConstant

    // used by core-image writer.
    public int unicodeIndex = -1;
    public int unicodeOffset= 0;
    public boolean dataWritten = false;
    public boolean handleWritten = false;

    private StringConstant( int t, int i ){
	tag = t;
	strIndex = i;
	nSlots = 1;
    }

    public static ConstantObject read( int t, DataInput i ) throws IOException{
	return new StringConstant( t, i.readUnsignedShort() );
    }

    public void resolve( ConstantObject table[] ){
	if (resolved) return;
	str = (UnicodeConstant)table[strIndex];
	resolved = true;
    }

    public void externalize( ConstantPool p ){
	str = (UnicodeConstant)p.add( str );
    }

    public void write( DataOutput o ) throws IOException{
	o.writeByte( tag );
	if ( resolved ){
	    o.writeShort( str.index );
	} else {
	    throw new DataFormatException("unresolved StringConstant");
	    //o.writeShort( strIndex );
	}
    }

    public String toString(){
	return "String: "+ ((resolved)?str.string:("[ "+strIndex+" ]"));
    }

    public void incReference() {
	references++;
	str.incReference();
    }

    public void decReference() {
	references--;
	str.decReference();
    }

    public int hashCode() {
	return tag + str.string.hashCode();
    }

    public boolean equals(Object o) {
	if (o instanceof StringConstant) {
	    StringConstant s = (StringConstant) o;
	    return str.string.equals(s.str.string);
	} else {
	    return false;
	}
    }

    public boolean isResolved(){ return true; }
}