高分寻求帮助-java反编译

Question

请求大虾帮助，还原下面的方法,不胜感激！public void run()
    {
        ThreadPoolExecutor threadpoolexecutor;
        init();
        threadpoolexecutor = getRunner();
        lastIdleTime = System.currentTimeMillis();
_L3:
        boolean flag;
        flag = false;
        if(udpSocket == null)
        {
            synchronized(this)
            {
                running = false;
            }
            break; /* Loop/switch isn't completed */
        }
        try
        {
label0:
            {
                byte abyte0[] = new byte[maxPacketSize];
                DatagramPacket datagrampacket = new DatagramPacket(abyte0, abyte0.length);
                udpSocket.receive(datagrampacket);
                long l1 = System.currentTimeMillis();
                int i = datagrampacket.getLength();
                if(i > 0)
                {
                    lastIdleTime = l1;
                    threadpoolexecutor.execute(new LoadBalancerListenerHandler(abyte0, 0, i));
                }
                synchronized(this)
                {
                    if(!quit)
                    {
                        break label0;
                    }
                    running = false;
                }
                break; /* Loop/switch isn't completed */
            }
        }
        catch(SocketTimeoutException sockettimeoutexception)
        {
label1:
            {
                synchronized(this)
                {
                    if(!quit)
                    {
                        break label1;
                    }
                    running = false;
                }
                break; /* Loop/switch isn't completed */
            }
        }
        catch(Exception exception1)
        {
label2:
            {
                synchronized(this)
                {
                    if(!quit)
                    {
                        break label2;
                    }
                    running = false;
                }
                break; /* Loop/switch isn't completed */
            }
        }
        loadbalancerlistener4;
        JVM INSTR monitorexit ;
        break MISSING_BLOCK_LABEL_237;
        exception3;
        throw exception3;
        loadbalancerlistener2;
        JVM INSTR monitorexit ;
          goto _L1
        exception4;
        throw exception4;
_L1:
        flag = true;
        break MISSING_BLOCK_LABEL_237;
        loadbalancerlistener3;
        JVM INSTR monitorexit ;
        break MISSING_BLOCK_LABEL_237;
        exception5;
        throw exception5;
        if(flag)
        {
            long l = System.currentTimeMillis();
            if(l - lastIdleTime > (long)idleInterval)
            {
                lastIdleTime = l;
                threadpoolexecutor.execute(new LoadBalancerListenerIdler());
            }
        }
        if(true) goto _L3; else goto _L2
_L2:
        try
        {
            synchronized(this)
            {
                if(udpSocket != null)
                {
                    udpSocket.close();
                }
                udpSocket = null;
            }
        }
        catch(Exception exception) { }
        killRunner();
        shutdown();
        return;
    }

Answer 1

你用的是什么反编译工具，有一个cjava感觉很好，你要么，发给你

Answer 2

jad ， 把带$号的也 反编译

Answer 3

我也是用的小颖，以前用CAVAJ，前辈说CAVAJ有时反编译会出错

Answer 4

答：楼主的这个代码没有经过混淆器，而且代码结构简单，很容易还原的。
1）由于楼主没有同时提供.class文件[提供了.class文件，可以完全准确还原]，楼主所提供的还原代码有部分信息丢失，还好由于程序简单，已正确判读还原了。
2）还原代码如下：
（1）楼主虽然只提供了这个run()方法的代码，但从代码中，已正确判读出该方法所在的类，类名一定叫“ LoadBalancerListener”，这是从代码中第一个判读还原出来的。
(2)代码中看起来混乱的部分实际上是由try()catch{}造句产生的，其实对经常判读class代码的程序员，它是很清楚的，一点也不混乱的。
（3）还原的代码：public void run() 
    { 
        ThreadPoolExecutor threadpoolexecutor; 
        init(); 
        threadpoolexecutor = getRunner(); 
        lastIdleTime = System.currentTimeMillis();      while(true){
        boolean flag; 
        flag = false; 
        if(udpSocket == null) 
        { 
            synchronized(this) 
            { 
                running = false; 
                break; 
            } 
           
        } 
        try 
        { 

                byte abyte0[] = new byte[maxPacketSize]; 
                DatagramPacket datagrampacket = new DatagramPacket(abyte0, abyte0.length); 
                udpSocket.receive(datagrampacket); 
                long l1 = System.currentTimeMillis(); 
                int i = datagrampacket.getLength(); 
                if(i > 0) 
                { 
                    lastIdleTime = l1; 
                   threadpoolexecutor.execute(new LoadBalancerListenerHandler(abyte0, 0, i)); 
                }    
               
                synchronized(this) 
                { 
                    if(quit) 
                    { 
                     running = false;
                     break;
                    } 
                     
                } 
               
            
        } 
        catch(SocketTimeoutException sockettimeoutexception) 
        { 
          synchronized(this) 
                { 
                    if(quit) 
                    { 
                     running = false;
                     break;
                    } 
                     
                } 
            flag=true;
        } 
        catch(Exception exception1) 
        { 
          synchronized(this) 
                { 
                    if(quit) 
                    { 
                     running = false;
                     break;
                    } 
                     
                } 
        }
       
        

        if(flag) 
        { 
            long l = System.currentTimeMillis(); 
            if(l - lastIdleTime > (long)idleInterval) 
            { 
                lastIdleTime = l; 
                threadpoolexecutor.execute(new LoadBalancerListenerIdler()); 
           } 
        }      }//while(true)

        try 
        { 
            synchronized(this) 
            { 
                if(udpSocket != null) 
                { 
                    udpSocket.close(); 
                } 
                udpSocket = null; 
            } 
        } 
        catch(Exception exception) { } 
        killRunner(); 
        shutdown(); 
        return; 
    }
（4）由于楼主没有提供.class文件，如何验证判读的结果是正确的？
将它编译成.class文件后，再用JAVA反编译程序反编译出代码，楼主可看到，结果[run()的反编译代码与楼主提供的是一模一样的]
//以下是对还原后的代码，编译成.class文件后，再用JAVA反编译程序反编译代码[与楼主的代码反编译代码相对比]
说明：为了程序能正确编译，加补了正确的类名，及程序中引用到的其它方法与变量。// Decompiled by Jad v1.5.8g. Copyright 2001 Pavel Kouznetsov.
// Jad home page: http://www.kpdus.com/jad.html
// Decompiler options: packimports(3) 
// Source File Name:   LoadBalancerListener.javaimport java.net.*;
import java.util.concurrent.ThreadPoolExecutor;public class LoadBalancerListener
{   
    public void run()
    {
        init();
        ThreadPoolExecutor threadpoolexecutor = getRunner();
        lastIdleTime = System.currentTimeMillis();
_L3:
        boolean flag;
        flag = false;
        if(udpSocket == null)
        {
            synchronized(this)
            {
                running = false;
            }
            break; /* Loop/switch isn't completed */
        }
        try
        {
label0:
            {
                byte abyte0[] = new byte[maxPacketSize];
                DatagramPacket datagrampacket = new DatagramPacket(abyte0, abyte0.length);
                udpSocket.receive(datagrampacket);
                long l1 = System.currentTimeMillis();
                int i = datagrampacket.getLength();
                if(i > 0)
                    lastIdleTime = l1;
                synchronized(this)
                {
                    if(!quit)
                        break label0;
                    running = false;
                }
                break; /* Loop/switch isn't completed */
            }
        }
        catch(SocketTimeoutException sockettimeoutexception)
        {
label1:
            {
                synchronized(this)
                {
                    if(!quit)
                        break label1;
                    running = false;
                }
                break; /* Loop/switch isn't completed */
            }
        }
        catch(Exception exception1)
        {
label2:
            {
                synchronized(this)
                {
                    if(!quit)
                        break label2;
                    running = false;
                }
                break; /* Loop/switch isn't completed */
            }
        }
        loadbalancerlistener4;
        JVM INSTR monitorexit ;
        break MISSING_BLOCK_LABEL_218;
        exception3;
        throw exception3;
        loadbalancerlistener2;
        JVM INSTR monitorexit ;
          goto _L1
        exception4;
        throw exception4;
_L1:
        flag = true;
        break MISSING_BLOCK_LABEL_218;
        loadbalancerlistener3;
        JVM INSTR monitorexit ;
        break MISSING_BLOCK_LABEL_218;
        exception5;
        throw exception5;
        long l;
        if(flag)
            l = System.currentTimeMillis();
        if(true) goto _L3; else goto _L2
_L2:
        try
        {
            synchronized(this)
            {
                if(udpSocket != null)
                    udpSocket.close();
                udpSocket = null;
            }
        }
        catch(Exception exception) { }
        killRunner();
        shutdown();
        return;
    }
//以下是加被的空的方法与变量名，目的是：能够正确通过编译。
 public LoadBalancerListener()
    {
        udpSocket = null;
        running = false;
        maxPacketSize = 0;
    }    void init()
    {
    }    void killRunner()
    {
    }    void shutdown()
    {
    }    ThreadPoolExecutor getRunner()
    {
        return null;
    }
    long lastIdleTime;
    DatagramSocket udpSocket;
    boolean running;
    boolean quit;
    int maxPacketSize;
}

Answer 5

答：到目前为止，所有的反编译软件对synchronized(){}及try{}catch{}都不能正确还原，但由于结构简单，经过人工判读，都可正确判读并正确还原。
一个建议：以后楼主不要只提供反编译的代码，要提供.class文件，这样好完全准确还原[而不用对还原后的代码，再次进行编译.class后，再反编译后与你原来的反编译代码进行对比。]

Answer 6

答：12楼中用于验证的人工判读还原后的JAVA代码[目的：与楼主的反编译代码对比]，如下：import java.util.concurrent.*;
import java.net.*;class LoadBalancerListenerHandler
{}//空，用于通过编译public class LoadBalancerListener {


public void run() 
    { 
        ThreadPoolExecutor threadpoolexecutor; 
        init(); 
        threadpoolexecutor = getRunner(); 
        lastIdleTime = System.currentTimeMillis();      while(true){
        boolean flag; 
        flag = false; 
        if(udpSocket == null) 
        { 
            synchronized(this) 
            { 
                running = false; 
                break; 
            } 
           
        } 
        try 
        { 

                byte abyte0[] = new byte[maxPacketSize]; 
                DatagramPacket datagrampacket = new DatagramPacket(abyte0, abyte0.length); 
                udpSocket.receive(datagrampacket); 
                long l1 = System.currentTimeMillis(); 
                int i = datagrampacket.getLength(); 
                if(i > 0) 
                { 
                    lastIdleTime = l1; 
                   // threadpoolexecutor.execute(new LoadBalancerListenerHandler(abyte0, 0, i)); 
                }    
               
                synchronized(this) 
                { 
                    if(quit) 
                    { 
                     running = false;
                     break;
                    } 
                     
                } 
               
            
        } 
        catch(SocketTimeoutException sockettimeoutexception) 
        { 
          synchronized(this) 
                { 
                    if(quit) 
                    { 
                     running = false;
                     break;
                    } 
                     
                } 
          flag=true;
        } 
        catch(Exception exception1) 
        { 
          synchronized(this) 
                { 
                    if(quit) 
                    { 
                     running = false;
                     break;
                    } 
                     
                } 
        }
       
        

        if(flag) 
        { 
            long l = System.currentTimeMillis(); 
          //  if(l - lastIdleTime > (long)idleInterval) 
          //  { 
         //       lastIdleTime = l; 
         //       threadpoolexecutor.execute(new LoadBalancerListenerIdler()); 
         //   } 
        } 
    }//while(true)

        try 
        { 
            synchronized(this) 
            { 
                if(udpSocket != null) 
                { 
                    udpSocket.close(); 
                } 
                udpSocket = null; 
            } 
        } 
        catch(Exception exception) { } 
        killRunner(); 
        shutdown(); 
        return; 
    }//以下是人为加上的内容，以便通过编译。
void init(){}
void killRunner(){}
    void  shutdown(){}

ThreadPoolExecutor getRunner(){return null;}
    long lastIdleTime;
    DatagramSocket udpSocket=null;
    boolean running=false,quit;
    int maxPacketSize=0;
    }
对上述代码进行编译.class文件后，再次反编译，看run()反编译代码与楼主的反编译代码对比，以进行验证。还是最好提供.class文件，这样可不用再次验证了。