Android Thread is not ending.It can not start again

Question

In this when the user clicks on the button a thread named "startAThread" starts and the button becomes invisible. After three seconds When the thread has done its work the button again becomes visible. When the user clicks on the button the second time it gives the error in LogCat:

Code:-

public class MainActivity extends Activity {

Handler mHandler;
Button button;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    button = (Button)findViewById(R.id.button);
    mHandler = new Handler(Looper.getMainLooper());

    button.setOnClickListener(new View.OnClickListener()
    {
        @Override
        public void onClick(View view)
        {
            startAthread.start();
            button.setVisibility(View.INVISIBLE);
        }
    });

}

Thread startAthread = new Thread(new Runnable()
{
    @Override
    public void run()
    {
        try
        {
            Thread.sleep(3000);
        }
        catch (InterruptedException e)
        {
            e.printStackTrace();
        }

        mHandler.post(new Runnable()
        {
            @Override
            public void run()
            {
                button.setVisibility(View.VISIBLE);
            }
        });

    }
});
}

Logcat:-

01-10 19:45:39.861  22473-22473/com.guptamanish712.threadtest W/dalvikvm﹕ threadid=1: thread exiting with uncaught exception (group=0x418002b8)
01-10 19:45:39.891  22473-22473/com.guptamanish712.threadtest E/AndroidRuntime﹕ FATAL EXCEPTION: main
    java.lang.IllegalThreadStateException: Thread already started.
            at java.lang.Thread.start(Thread.java:1045)
            at com.guptamanish712.threadtest.MainActivity$1.onClick(MainActivity.java:29)
            at android.view.View.performClick(View.java:4295)
            at android.view.View$PerformClick.run(View.java:17456)
            at android.os.Handler.handleCallback(Handler.java:615)
            at android.os.Handler.dispatchMessage(Handler.java:92)
            at android.os.Looper.loop(Looper.java:174)
            at android.app.ActivityThread.main(ActivityThread.java:4952)
            at java.lang.reflect.Method.invokeNative(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:511)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1027)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:794)
            at dalvik.system.NativeStart.main(Native Method)

Threads in Java cannot be restarted once they have stopped. They stop when their `run()` method finishes executing. In your example, you create a thread once, call start on it when somebody clicks a button, and call start again when somebody clicks the button again. — Todd, Jan 10 '15 at 14:42
then how to do the same work again in this activity. Should I define one more thread with different name but same code — manish, Jan 10 '15 at 14:46
You can implement this logic using mHandler.postDelayed(Runnable,3000) method , Then you can avoid the thread. — Krish, Jan 10 '15 at 14:50
but i don't want to avoid the thread. I want to do the same work twice — manish, Jan 10 '15 at 14:53
You want to run the same thread twice? If yes, see this question http://stackoverflow.com/q/19888940/1979347 — Rohan Kandwal, Jan 10 '15 at 15:07

score 0 · Answer 1 · answered Jan 10 '15 at 17:02

      button.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            new Thread(new Runnable() {
                @Override
                public void run() {
                    try {
                        Thread.sleep(3000);
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }

                    mHandler.post(new Runnable() {
                        @Override
                        public void run() {
                            button.setVisibility(View.VISIBLE);

                        }
                    });

                }
            }).start();
            button.setVisibility(View.INVISIBLE);
        }
    });

Android Thread is not ending.It can not start again

1 Answers1