attributesorter.java

来自「proguard 一个java的混淆器」· Java 代码 · 共 90 行

/*
 * 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.editor;

import proguard.classfile.*;
import proguard.classfile.attribute.*;
import proguard.classfile.attribute.visitor.AttributeVisitor;
import proguard.classfile.util.SimplifiedVisitor;
import proguard.classfile.visitor.*;

import java.util.*;

/**
 * This ClassVisitor sorts the attributes of the classes that it visits.
 * The sorting order is based on the types of the attributes.
 *
 * @author Eric Lafortune
 */
public class AttributeSorter
extends      SimplifiedVisitor
implements   ClassVisitor, MemberVisitor, AttributeVisitor, Comparator
{
    // Implementations for ClassVisitor.

    public void visitProgramClass(ProgramClass programClass)
    {
        // Sort the attributes.
        Arrays.sort(programClass.attributes, 0, programClass.u2attributesCount, this);

        // Sort the attributes of the class members.
        programClass.fieldsAccept(this);
        programClass.methodsAccept(this);
    }


    // Implementations for MemberVisitor.

    public void visitProgramMember(ProgramClass programClass, ProgramMember programMember)
    {
        // Sort the attributes.
        Arrays.sort(programMember.attributes, 0, programMember.u2attributesCount, this);

        // Sort the attributes of the attributes.
        programMember.attributesAccept(programClass, this);
    }


    // Implementations for AttributeVisitor.

    public void visitAnyAttribute(Clazz clazz, Attribute attribute) {}


    public void visitCodeAttribute(Clazz clazz, Method method, CodeAttribute codeAttribute)
    {
        // Sort the attributes.
        Arrays.sort(codeAttribute.attributes, 0, codeAttribute.u2attributesCount, this);
    }


    // Implementations for Comparator.

    public int compare(Object object1, Object object2)
    {
        Attribute attribute1 = (Attribute)object1;
        Attribute attribute2 = (Attribute)object2;

        return attribute1.u2attributeNameIndex < attribute2.u2attributeNameIndex ? -1 :
               attribute1.u2attributeNameIndex > attribute2.u2attributeNameIndex ?  1 :
                                                                                    0;
    }
}