/*******************************************************************************
* Copyright (c) 2014 Jeff Martin.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the GNU Public License v3.0
* which accompanies this distribution, and is available at
* http://www.gnu.org/licenses/gpl.html
*
* Contributors:
* Jeff Martin - initial API and implementation
******************************************************************************/
package cuchaz.enigma.analysis;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.Enumeration;
import java.util.Iterator;
import java.util.List;
import java.util.jar.JarEntry;
import java.util.jar.JarFile;
import javassist.ByteArrayClassPath;
import javassist.ClassPool;
import javassist.CtClass;
import javassist.NotFoundException;
import javassist.bytecode.Descriptor;
import com.google.common.collect.Lists;
import cuchaz.enigma.Constants;
import cuchaz.enigma.mapping.ClassEntry;
public class JarClassIterator implements Iterator<CtClass>
{
private JarFile m_jar;
private Iterator<JarEntry> m_iter;
public JarClassIterator( JarFile jar )
{
m_jar = jar;
// get the jar entries that correspond to classes
List<JarEntry> classEntries = Lists.newArrayList();
Enumeration<JarEntry> entries = m_jar.entries();
while( entries.hasMoreElements() )
{
JarEntry entry = entries.nextElement();
// is this a class file?
if( entry.getName().endsWith( ".class" ) )
{
classEntries.add( entry );
}
}
m_iter = classEntries.iterator();
}
@Override
public boolean hasNext( )
{
return m_iter.hasNext();
}
@Override
public CtClass next( )
{
JarEntry entry = m_iter.next();
try
{
return getClass( m_jar, entry );
}
catch( IOException | NotFoundException ex )
{
throw new Error( "Unable to load class: " + entry.getName() );
}
}
@Override
public void remove( )
{
throw new UnsupportedOperationException();
}
public static List<ClassEntry> getClassEntries( JarFile jar )
{
List<ClassEntry> classEntries = Lists.newArrayList();
Enumeration<JarEntry> entries = jar.entries();
while( entries.hasMoreElements() )
{
JarEntry entry = entries.nextElement();
// is this a class file?
if( !entry.isDirectory() && entry.getName().endsWith( ".class" ) )
{
classEntries.add( getClassEntry( entry ) );
}
}
return classEntries;
}
public static Iterable<CtClass> classes( final JarFile jar )
{
return new Iterable<CtClass>( )
{
@Override
public Iterator<CtClass> iterator( )
{
return new JarClassIterator( jar );
}
};
}
public static CtClass getClass( JarFile jar, ClassEntry classEntry )
{
try
{
return getClass( jar, new JarEntry( classEntry.getName() + ".class" ) );
}
catch( IOException | NotFoundException ex )
{
throw new Error( "Unable to load class: " + classEntry.getName() );
}
}
private static CtClass getClass( JarFile jar, JarEntry entry )
throws IOException, NotFoundException
{
// read the class into a buffer
ByteArrayOutputStream bos = new ByteArrayOutputStream();
byte[] buf = new byte[Constants.KiB];
int totalNumBytesRead = 0;
InputStream in = jar.getInputStream( entry );
while( in.available() > 0 )
{
int numBytesRead = in.read( buf );
if( numBytesRead < 0 )
{
break;
}
bos.write( buf, 0, numBytesRead );
// sanity checking
totalNumBytesRead += numBytesRead;
if( totalNumBytesRead > Constants.MiB )
{
throw new Error( "Class file " + entry.getName() + " larger than 1 MiB! Something is wrong!" );
}
}
// get a javassist handle for the class
String className = Descriptor.toJavaName( getClassEntry( entry ).getName() );
ClassPool classPool = new ClassPool();
classPool.insertClassPath( new ByteArrayClassPath( className, bos.toByteArray() ) );
return classPool.get( className );
}
private static ClassEntry getClassEntry( JarEntry entry )
{
return new ClassEntry( entry.getName().substring( 0, entry.getName().length() - ".class".length() ) );
}
}