Android Dynamic Display Time _android

How can the dynamic implementation of the time? Maybe you just don't understand the new entrants. If you don't know the words, see the code (code is the best teacher). Laugh

public void OnCreate (Bundle savedinstancestate) { 
    super.oncreate (savedinstancestate); 
    Setcontentview (r.layout.main); 
    textview= (TextView) Findviewbyid (r.id.time); 
      Handler = new Handler () {public 
        void Handlemessage (msg) { 
          textview.settext ((String) msg.obj); 
        } 
      ; 
    New Thread (This). Start (); 
  @Override public 
  Void Run () { 
    //TODO auto-generated a stub 
    try {while 
      (true) { 
        SimpleDateFormat sdf=new SimpleDateFormat ("YYYY year mm month DD Day  HH:mm:ss"); 
        String Str=sdf.format (New Date ()); 
        Handler.sendmessage (Handler.obtainmessage (100,STR)); 
        Thread.Sleep (1000); 
      } 
    catch (Interruptedexception e) { 
      //TODO auto-generated catch block 
      e.printstacktrace (); 
    } 
  

As you can see from the above code, this is a multithreaded. The data is updated when the system is acquired in real time.