numberformat exception android
<p>In my programme, programme crashes when I try to calculate without giving number values to edit-text boxes.
If I give values, app works properly. when It crashes I get following errors in the log cat</p>

<pre><code>11-07 23:18:51.253: E/AndroidRuntime(450): FATAL EXCEPTION: main
11-07 23:18:51.253: E/AndroidRuntime(450): java.lang.NumberFormatException: 
11-07 23:18:51.253: E/AndroidRuntime(450):  at org.apache.harmony.luni.util.FloatingPointParser.parseDouble(FloatingPointParser.java:267)
11-07 23:18:51.253: E/AndroidRuntime(450):  at java.lang.Double.parseDouble(Double.java:318)
11-07 23:18:51.253: E/AndroidRuntime(450):  at com.xxx.xxx.Page1SubActivity$2.onClick(Page1SubActivity.java:77)
11-07 23:18:51.253: E/AndroidRuntime(450):  at android.view.View.performClick(View.java:2485)
11-07 23:18:51.253: E/AndroidRuntime(450):  at android.view.View$PerformClick.run(View.java:9080)
11-07 23:18:51.253: E/AndroidRuntime(450):  at android.os.Handler.handleCallback(Handler.java:587)
11-07 23:18:51.253: E/AndroidRuntime(450):  at android.os.Handler.dispatchMessage(Handler.java:92)
11-07 23:18:51.253: E/AndroidRuntime(450):  at android.os.Looper.loop(Looper.java:123)
11-07 23:18:51.253: E/AndroidRuntime(450):  at android.app.ActivityThread.main(ActivityThread.java:3683)
11-07 23:18:51.253: E/AndroidRuntime(450):  at java.lang.reflect.Method.invokeNative(Native Method)
11-07 23:18:51.253: E/AndroidRuntime(450):  at java.lang.reflect.Method.invoke(Method.java:507)
11-07 23:18:51.253: E/AndroidRuntime(450):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
11-07 23:18:51.253: E/AndroidRuntime(450):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
11-07 23:18:56.723: I/Process(450): Sending signal. PID: 450 SIG: 9
</code></pre>

<p>here is the Java code.</p>

<pre><code>ImageButton rightbuton = (ImageButton) findViewById(R.id.rightbutton);
        rightbuton.setOnClickListener(new OnClickListener() {
            public void onClick(View v) {

                edit1 = (EditText) findViewById(R.id.editText1);
                edit2 = (EditText) findViewById(R.id.editText2);
                textview = (TextView) findViewById(R.id.textView5);

                Double number2 = 0.0;
                Double number3 = 0.0;



                if (edit1.getText().toString().trim().length()&gt;0 ) {
                    number2 = Double
                            .parseDouble(edit1.getText().toString());

                }
                if(edit2.getText().toString().trim().length()&gt;0){
                    number3 = Double
                            .parseDouble(edit2.getText().toString());
                }

                number3 = number2 * number3;

                int number2int = (int) (number2 * number3);
                int number3int = (int) (number3 / 40);

                number2 = number2 * number3;
                number3 = number3 / 40;

                if (number2int - number2 != 0) {
                    String number2val = Double.toString(number2);
                    textview.setText(number2val);

                } else {
                    String number2val = Integer.toString(number2int);
                    textview.setText(number2val);
                    // label.text = [NSString stringWithFormat:@"%d",
                    // number2int];

                }

                if (number3int - number3 != 0) {
                    String number3val = Double.toString(number3);
                    textview.setText(number3val);

                } else {

                    String number3val = Integer.toString(number3int);
                    textview.setText(number3val);

                }

            }
        });
</code></pre>
