stringconstant.java

ProGuard 是一个免费的 Java类文件的压缩

/*
 * ProGuard -- shrinking, optimization, obfuscation, and preverification
 *             of Java bytecode.
 *
 * Copyright (c) 2002-2007 Eric Lafortune ([e-mail])
 *
 * This library is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation; either version 2 of the License, or (at your option)
 * any later version.
 *
 * This library 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 Lesser General Public License
 * for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this library; if not, write to the Free Software Foundation,
 * Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */
package proguard.classfile.constant;

import proguard.classfile.*;
import proguard.classfile.constant.visitor.ConstantVisitor;
import proguard.classfile.visitor.*;

import java.io.*;

/**
 * This Constant represents a string constant in the constant pool.
 *
 * @author Eric Lafortune
 */
public class StringConstant extends Constant
{
    public int u2stringIndex;

    /**
     * An extra field pointing to the referenced Clazz object, if this
     * string is being used in Class.forName() or .class constructs.
     * This field is filled out by the <code>{@link
     * proguard.classfile.util.ClassReferenceInitializer ClassReferenceInitializer}</code>.
     * References to library classes are not filled out.
     */
    public Clazz referencedClass;


    /**
     * Creates an uninitialized StringConstant.
     */
    public StringConstant()
    {
    }


    /**
     * Creates a new StringConstant with the given string index.
     * @param u2stringIndex   the index of the string in the constant pool.
     * @param referencedClass the referenced class, if any.
     */
    public StringConstant(int   u2stringIndex,
                          Clazz referencedClass)
    {
        this.u2stringIndex   = u2stringIndex;
        this.referencedClass = referencedClass;
    }


    /**
     * Returns the string value.
     */
    public String getString(Clazz clazz)
    {
        return clazz.getString(u2stringIndex);
    }


    // Implementations for Constant.

    public int getTag()
    {
        return ClassConstants.CONSTANT_String;
    }

    public void accept(Clazz clazz, ConstantVisitor constantVisitor)
    {
        constantVisitor.visitStringConstant(clazz, this);
    }


    /**
     * Lets the referenced class accept the given visitor.
     */
    public void referencedClassAccept(ClassVisitor classVisitor)
    {
        if (referencedClass != null)
        {
            referencedClass.accept(classVisitor);
        }
    }
}