public static final void prepare() { 
  if (sThreadLocal.get() != null) { 
   throw new RuntimeException("Only one Looper may be created per thread"); 
  } 
  sThreadLocal.set(new Looper(true)); 
} 

private Looper(boolean quitAllowed) { 
  mQueue = new MessageQueue(quitAllowed); 
  mRun = true; 
  mThread = Thread.currentThread(); 
} 

public static void loop() { 
  final Looper me = myLooper(); 
  if (me == null) { 
   throw new RuntimeException("No Looper; Looper.prepare() wasn't called on this thread."); 
  } 
  final MessageQueue queue = me.mQueue; 
 
  // Make sure the identity of this thread is that of the local process, 
  // and keep track of what that identity token actually is. 
  Binder.clearCallingIdentity(); 
  final long ident = Binder.clearCallingIdentity(); 
 
  for (;;) { 
   Message msg = queue.next(); // might block 
   if (msg == null) { 
    // No message indicates that the message queue is quitting. 
    return; 
   } 
 
   // This must be in a local variable, in case a UI event sets the logger 
   Printer logging = me.mLogging; 
   if (logging != null) { 
    logging.println(">>>>> Dispatching to " + msg.target + " " + 
      msg.callback + ": " + msg.what); 
   } 
 
   msg.target.dispatchMessage(msg); 
 
   if (logging != null) { 
    logging.println("<<<<< Finished to " + msg.target + " " + msg.callback); 
   } 
 
   // Make sure that during the course of dispatching the 
   // identity of the thread wasn't corrupted. 
   final long newIdent = Binder.clearCallingIdentity(); 
   if (ident != newIdent) { 
    Log.wtf(TAG, "Thread identity changed from 0x" 
      + Long.toHexString(ident) + " to 0x" 
      + Long.toHexString(newIdent) + " while dispatching to " 
      + msg.target.getClass().getName() + " " 
      + msg.callback + " what=" + msg.what); 
   } 
 
   msg.recycle(); 
  } 
} 

public static Looper myLooper() {
return sThreadLocal.get();
}

public Handler() { 
  this(null, false); 
} 
public Handler(Callback callback, boolean async) { 
  if (FIND_POTENTIAL_LEAKS) { 
   final Class<? extends Handler> klass = getClass(); 
   if ((klass.isAnonymousClass() || klass.isMemberClass() || klass.isLocalClass()) && 
     (klass.getModifiers() & Modifier.STATIC) == 0) { 
    Log.w(TAG, "The following Handler class should be static or leaks might occur: " + 
     klass.getCanonicalName()); 
   } 
  } 
 
  mLooper = Looper.myLooper(); 
  if (mLooper == null) { 
   throw new RuntimeException( 
    "Can't create handler inside thread that has not called Looper.prepare()"); 
  } 
  mQueue = mLooper.mQueue; 
  mCallback = callback; 
  mAsynchronous = async; 
 } 

public final boolean sendMessage(Message msg) 
 { 
  return sendMessageDelayed(msg, 0); 
 } 

public final boolean sendEmptyMessageDelayed(int what, long delayMillis) { 
  Message msg = Message.obtain(); 
  msg.what = what; 
  return sendMessageDelayed(msg, delayMillis); 
 } 

public final boolean sendMessageDelayed(Message msg, long delayMillis) 
 { 
  if (delayMillis < 0) { 
   delayMillis = 0; 
  } 
  return sendMessageAtTime(msg, SystemClock.uptimeMillis() + delayMillis); 
 } 

public boolean sendMessageAtTime(Message msg, long uptimeMillis) { 
  MessageQueue queue = mQueue; 
  if (queue == null) { 
   RuntimeException e = new RuntimeException( 
     this + " sendMessageAtTime() called with no mQueue"); 
   Log.w("Looper", e.getMessage(), e); 
   return false; 
  } 
  return enqueueMessage(queue, msg, uptimeMillis); 
 } 

private boolean enqueueMessage(MessageQueue queue, Message msg, long uptimeMillis) { 
  msg.target = this; 
  if (mAsynchronous) { 
   msg.setAsynchronous(true); 
  } 
  return queue.enqueueMessage(msg, uptimeMillis); 
 } 

public void dispatchMessage(Message msg) { 
  if (msg.callback != null) { 
   handleCallback(msg); 
  } else { 
   if (mCallback != null) { 
    if (mCallback.handleMessage(msg)) { 
     return; 
    } 
   } 
   handleMessage(msg); 
  } 
 } 

/** 
 * Subclasses must implement this to receive messages. 
 */ 
 public void handleMessage(Message msg) { 
 } 
 

private Handler mHandler = new Handler() 
 { 
  public void handleMessage(android.os.Message msg) 
  { 
   switch (msg.what) 
   { 
   case value: 
     
    break; 
 
   default: 
    break; 
   } 
  }; 
 }; 

mHandler.post(new Runnable() 
  { 
   @Override 
   public void run() 
   { 
    Log.e("TAG", Thread.currentThread().getName()); 
    mTxt.setText("yoxi"); 
   } 
  }); 

public final boolean post(Runnable r) 
 { 
  return sendMessageDelayed(getPostMessage(r), 0); 
 } 

private static Message getPostMessage(Runnable r) { 
  Message m = Message.obtain(); 
  m.callback = r; 
  return m; 
 } 

public final boolean sendMessageDelayed(Message msg, long delayMillis) 
 { 
  if (delayMillis < 0) { 
   delayMillis = 0; 
  } 
  return sendMessageAtTime(msg, SystemClock.uptimeMillis() + delayMillis); 
 } 

public boolean sendMessageAtTime(Message msg, long uptimeMillis) { 
  MessageQueue queue = mQueue; 
  if (queue == null) { 
   RuntimeException e = new RuntimeException( 
     this + " sendMessageAtTime() called with no mQueue"); 
   Log.w("Looper", e.getMessage(), e); 
   return false; 
  } 
  return enqueueMessage(queue, msg, uptimeMillis); 
 } 

public void dispatchMessage(Message msg) { 
  if (msg.callback != null) { 
   handleCallback(msg); 
  } else { 
   if (mCallback != null) { 
    if (mCallback.handleMessage(msg)) { 
     return; 
    } 
   } 
   handleMessage(msg); 
  } 
 } 

new Thread() 
  { 
   private Handler handler; 
   public void run() 
   { 
 
    Looper.prepare(); 
     
    handler = new Handler() 
    { 
     public void handleMessage(android.os.Message msg) 
     { 
      Log.e("TAG",Thread.currentThread().getName()); 
     }; 
    }

  }