Application stops when clicked on Button

Question

Whenever i click on Submit button, i get an error "Unfortunately, Application has stopped working." Please can you help me out.

Code-

    public void onClick(View v) {
            TextView t = (TextView) findViewById(R.id.textView4);   
            if(from == to)
            {
                Toast.makeText(getApplicationContext(), "Invalid", 4000).show();

            }


            else
            {                                       
                  try {
                     s = getJson("URL");                        
                    JSONObject jObj;
                    jObj = new JSONObject(s);
                    String exResult = jObj.getJSONObject("query").getJSONObject("results").getJSONObject("rate").getString("Rate");
                    t.setText(exResult);
                    } catch (JSONException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }
                    catch (ClientProtocolException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    } catch (IOException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }                                                    
                }   

            }                               
    });
}

LogCat -

03-15 12:06:17.508: E/AndroidRuntime(877): FATAL EXCEPTION: main 03-15 12:06:17.508: E/AndroidRuntime(877): android.os.NetworkOnMainThreadException 03-15 12:06:17.508: E/AndroidRuntime(877): at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1117) 03-15 12:06:17.508: E/AndroidRuntime(877): at java.net.InetAddress.lookupHostByName(InetAddress.java:385) 03-15 12:06:17.508: E/AndroidRuntime(877): at java.net.InetAddress.getAllByNameImpl(InetAddress.java:236) 03-15 12:06:17.508: E/AndroidRuntime(877): at java.net.InetAddress.getAllByName(InetAddress.java:214) 03-15 12:06:17.508: E/AndroidRuntime(877): at org.apache.http.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:137) 03-15 12:06:17.508: E/AndroidRuntime(877): at org.apache.http.impl.conn.AbstractPoolEntry.open(AbstractPoolEntry.java:164) 03-15 12:06:17.508: E/AndroidRuntime(877): at org.apache.http.impl.conn.AbstractPooledConnAdapter.open(AbstractPooledConnAdapter.java:119) 03-15 12:06:17.508: E/AndroidRuntime(877): at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:360) 03-15 12:06:17.508: E/AndroidRuntime(877): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:555) 03-15 12:06:17.508: E/AndroidRuntime(877): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:487) 03-15 12:06:17.508: E/AndroidRuntime(877): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:465) 03-15 12:06:17.508: E/AndroidRuntime(877): at myandroid.myfirstmodule.sconverter.getJson(sconverter.java:163) 03-15 12:06:17.508: E/AndroidRuntime(877): at myandroid.myfirstmodule.sconverter$1.onClick(sconverter.java:96) 03-15 12:06:17.508: E/AndroidRuntime(877): at android.view.View.performClick(View.java:4084) 03-15 12:06:17.508: E/AndroidRuntime(877): at android.view.View$PerformClick.run(View.java:16966) 03-15 12:06:17.508: E/AndroidRuntime(877): at android.os.Handler.handleCallback(Handler.java:615) 03-15 12:06:17.508: E/AndroidRuntime(877): at android.os.Handler.dispatchMessage(Handler.java:92) 03-15 12:06:17.508: E/AndroidRuntime(877): at android.os.Looper.loop(Looper.java:137) 03-15 12:06:17.508: E/AndroidRuntime(877): at android.app.ActivityThread.main(ActivityThread.java:4745) 03-15 12:06:17.508: E/AndroidRuntime(877): at java.lang.reflect.Method.invokeNative(Native Method) 03-15 12:06:17.508: E/AndroidRuntime(877): at java.lang.reflect.Method.invoke(Method.java:511) 03-15 12:06:17.508: E/AndroidRuntime(877): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786) 03-15 12:06:17.508: E/AndroidRuntime(877): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553) 03-15 12:06:17.508: E/AndroidRuntime(877): at dalvik.system.NativeStart.main(Native Method)

Answer 1

Why don't you implement the onclickevent in the layout like this:

<Button
    android:id="@+id/button2"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Click Here"
    android:onClick="btnClicked" />

Then define the method btnClicked(). I think that way you can use this onClickListener with a custom method. You can even use the same method for the button1 and inside of it determine which button has been called.

Answer 2

You might try to move the listener of the second button from the else block. I think it is not a good practice to place a listener inside another listener

Answer 3

I am not sure what exactly is your goal in your code. But I don't think placing submitfinal's onClick inside button b's onCLick is a right thing to do. You need to handle them separately. If you want that in one onClickListener, you can do:

  int x, y, product; 
  public OnClickListener buttonClickListener = new OnClickListener() {
        @Override
        public void onClick(View v) {
                switch (v.getId()) {

            case <button b id>: 
                //fetch values of x and y
                                    x = Integer.parseInt(yourtextbox1.getText().toString());
                                    y = Integer.parseInt(yourtextbox2.getText().toString());
            break;
            case <button submit final id>: 
                //multiply x and y
                       product = x*y;
                    //display the product
                       yourtextbox3.setText(product);
            break;
            }
     };

 b.setOnClickListener(buttonClickListener);
 submitFinal.setOnClickListener(buttonClickListener);

EDIT:

On your current code, move the lines:

 t = (TextView) findViewById(R.id.textView4);    
 displayfinal = (TextView) findViewById(R.id.textView3);

outside your onclick listener.

Hope that helps.