how to solve the exception in android

i have written HttpDelete in android to call REST web service.

public void onCreate(Bundle savedInstanceState)
    {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    TextView txt = (TextView) findViewById(R.id.textView1);
    txt.setText(getInputStreamFromUrl("http://192.168.37.241:8080/kyaw/k"));
    }

    public static String getInputStreamFromUrl(String url) {
          InputStream content = null;
          HttpResponse response = null;
          try {

            DefaultHttpClient httpclient = new DefaultHttpClient();             
            HttpDelete delete=new HttpDelete(url);
            put.setHeader("Content-Type","application/vnd.org.snia.cdmi.container");
            response = httpclient.execute(delete);
            content = response.getEntity().getContent();
          }catch (Exception e) {
            Log.e("[DELETE REQUEST]", "Network exception");
          }
            St开发者_运维问答ring result=response.getStatusLine().toString()+"\n"+response.getHeaders(url);
            return result;
        }

And I get the exception which is

05-23 08:30:16.868: ERROR/[DELETE REQUEST](1197): Network exception
05-23 08:30:16.868: DEBUG/AndroidRuntime(1197): Shutting down VM
05-23 08:30:16.878: WARN/dalvikvm(1197): threadid=1: thread exiting with uncaught exception (group=0x40015560)
05-23 08:30:16.908: ERROR/AndroidRuntime(1197): FATAL EXCEPTION: main
05-23 08:30:16.908: ERROR/AndroidRuntime(1197): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.test/com.test.putandroid}: java.lang.NullPointerException

Do anyone know why?

did you check for the manifest file for Internet permission?

No idea for the network exception (yet) but the last NPE is most likely because the previous exception is thrown before response has been initialized through httpclient.execute(delete).

You should rewrite your catch block and write the name of the catched exception and the message to the log.

In the onCreate() function on line 4 we find that after initializing your TextView you are trying to set a value.

You must use a Handler object because you cannot update an UI objects while in a separate thread.

Here is some link for your help

http://www.tutorialforandroid.com/2009/01/using-handler-in-android.html

http://thedevelopersinfo.com/?p=150