ConstantValueAttribute.java

/*******************************************************************************
 * Copyright (c) 1998, 2015 Oracle and/or its affiliates. All rights reserved.
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v1.0 and Eclipse Distribution License v. 1.0
 * which accompanies this distribution.
 * The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html
 * and the Eclipse Distribution License is available at
 * http://www.eclipse.org/org/documents/edl-v10.php.
 *
 * Contributors:
 *     Oracle - initial API and implementation from Oracle TopLink
******************************************************************************/
package org.eclipse.persistence.tools.workbench.utility.classfile;

import java.io.IOException;
import java.io.PrintWriter;

import org.eclipse.persistence.tools.workbench.utility.classfile.tools.ClassFileDataInputStream;
import org.eclipse.persistence.tools.workbench.utility.io.IndentingPrintWriter;


/**
 * This class models a constant value attribute:
 *     u2 attribute_name_index;
 *     u4 attribute_length;
 *     u2 constantvalue_index;
 *
 * See "The Java Virtual Machine Specification" Chapter 4.
 */
public class ConstantValueAttribute extends Attribute {
    private short constantValueIndex;

    /**
     * Construct a constant value attribute from the specified stream
     * of byte codes.
     */
    ConstantValueAttribute(ClassFileDataInputStream stream, short nameIndex, AttributePool pool) throws IOException {
        super(stream, nameIndex, pool);
    }

    void initializeInfo(ClassFileDataInputStream stream) throws IOException {
        this.constantValueIndex = stream.readU2();
    }

    void displayInfoStringOn(IndentingPrintWriter writer) {
        this.constantValue().displayStringOn(writer);
        writer.println();
    }

    public void printFieldInitializationClauseOn(PrintWriter writer) {
        writer.print(" = ");
        this.constantValue().printFieldInitializationClauseOn(writer);
    }

    public Object fieldConstantValue() {
        return this.constantValue().value();
    }

    public Constant constantValue() {
        return this.constantPool().get(this.constantValueIndex);
    }

    public LongConstant longValue() {
        return (LongConstant) this.constantValue();
    }

    public FloatConstant floatValue() {
        return (FloatConstant) this.constantValue();
    }

    public DoubleConstant doubleValue() {
        return (DoubleConstant) this.constantValue();
    }

    public IntegerConstant integerValue() {
        return (IntegerConstant) this.constantValue();
    }

    public StringConstant stringValue() {
        return (StringConstant) this.constantValue();
    }

    public void accept(Visitor visitor) {
        visitor.visit(this);
    }

    public short getConstantValueIndex() {
        return this.constantValueIndex;
    }

    void toString(StringBuffer sb) {
        this.constantValue().toString(sb);
    }

}