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ProGuard is a free Java class file shrinker, optimizer, and obfuscator. It removes unused classes, fields, methods, and attributes. It then optimizes the bytecode. It then renames the remaining classes, fields, and methods using short meaningless names. Finally, it preverifies the processed code for Java 6 or for Java Micro Edition.
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/*
* ProGuard -- shrinking, optimization, obfuscation, and preverification
* of Java bytecode.
*
* Copyright (c) 2002-2009 Eric Lafortune ([email protected])
*
* This program 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 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 for
* more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
package proguard.classfile.util;
import proguard.classfile.*;
import proguard.classfile.visitor.*;
/**
* This class provides methods to find class members in a given class or in its
* hierarchy.
*
* @author Eric Lafortune
*/
public class MemberFinder
extends SimplifiedVisitor
implements MemberVisitor
{
private static class MemberFoundException extends RuntimeException {}
private static final MemberFoundException MEMBER_FOUND = new MemberFoundException();
private Clazz clazz;
private Member member;
/**
* Finds the field with the given name and descriptor in the given
* class or its hierarchy.
*/
public Field findField(Clazz referencingClass,
Clazz clazz,
String name,
String descriptor)
{
return (Field)findMember(referencingClass, clazz, name, descriptor, true);
}
/**
* Finds the method with the given name and descriptor in the given
* class or its hierarchy.
*/
public Method findMethod(Clazz referencingClass,
Clazz clazz,
String name,
String descriptor)
{
return (Method)findMember(referencingClass, clazz, name, descriptor, false);
}
/**
* Finds the class member with the given name and descriptor in the given
* class or its hierarchy.
*/
public Member findMember(Clazz referencingClass,
Clazz clazz,
String name,
String descriptor,
boolean isField)
{
// Organize a search in the hierarchy of superclasses and interfaces.
// The class member may be in a different class, if the code was
// compiled with "-target 1.2" or higher (the default in JDK 1.4).
try
{
this.clazz = null;
this.member = null;
clazz.hierarchyAccept(true, true, true, false, isField ?
(ClassVisitor)new NamedFieldVisitor(name, descriptor,
new MemberClassAccessFilter(referencingClass, this)) :
(ClassVisitor)new NamedMethodVisitor(name, descriptor,
new MemberClassAccessFilter(referencingClass, this)));
}
catch (MemberFoundException ex)
{
// We've found the member we were looking for.
}
return member;
}
/**
* Returns the corresponding class of the most recently found class
* member.
*/
public Clazz correspondingClass()
{
return clazz;
}
/**
* Returns whether the given method is overridden anywhere down the class
* hierarchy.
*/
public boolean isOverriden(Clazz clazz,
Method method)
{
String name = method.getName(clazz);
String descriptor = method.getDescriptor(clazz);
// Go looking for the method down the class hierarchy.
try
{
this.clazz = null;
this.member = null;
clazz.hierarchyAccept(false, false, false, true,
new NamedMethodVisitor(name, descriptor,
new MemberAccessFilter(0, ClassConstants.INTERNAL_ACC_PRIVATE, this)));
}
catch (MemberFoundException ex)
{
// We've found an overriding method.
return true;
}
return false;
}
/**
* Returns whether the given field is shadowed anywhere down the class
* hierarchy.
*/
public boolean isShadowed(Clazz clazz,
Field field)
{
String name = field.getName(clazz);
String descriptor = field.getDescriptor(clazz);
// Go looking for the field down the class hierarchy.
try
{
this.clazz = null;
this.member = null;
clazz.hierarchyAccept(false, false, false, true,
new NamedFieldVisitor(name, descriptor,
new MemberAccessFilter(0, ClassConstants.INTERNAL_ACC_PRIVATE, this)));
}
catch (MemberFoundException ex)
{
// We've found a shadowing field.
return true;
}
return false;
}
// // Implementations for ClassVisitor.
//
// private void visitAnyClass(Clazz clazz)
// {
// if (member == null)
// {
// member = isField ?
// (Member)clazz.findField(name, descriptor) :
// (Member)clazz.findMethod(name, descriptor);
//
// if (member != null)
// {
// this.clazz = clazz;
// }
// }
// }
// Implementations for MemberVisitor.
public void visitAnyMember(Clazz clazz, Member member)
{
this.clazz = clazz;
this.member = member;
throw MEMBER_FOUND;
}
}