Android - NullPointerException on EditText field

Question

I've been following the Android tutorials and created MyFirstApp (see http://developer.android.com/training/basics/firstapp/index.html) and I can launch the app ok on the emulator, but upon entering a message and hitting "send" I get an IllegalStateException caused by a NullPointerException at this line in the below code:

String message = editText.getText().toString();

Upon debugging, it is clear that editText is null at this point, but I cannot see why, or anything I've missed in the tutorial.

My MainActivity class:

package com.example.myfirstapp;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.Menu;
import android.view.View;    
import android.widget.EditText;


/**
 * <p>Main Activity class for the App</p>
 *
 * @author - thebloodguy
 */
public class MainActivity extends Activity {

    //~ ----------------------------------------------------------------------------------------------------------------
    //~ Static fields/initializers 
    //~ ----------------------------------------------------------------------------------------------------------------

    /** Key to the extra message data in the sendMessage intent */
    public static final String EXTRA_MESSAGE = "com.example.myfirstapp.MESSAGE";

    //~ ----------------------------------------------------------------------------------------------------------------
    //~ Methods 
    //~ ----------------------------------------------------------------------------------------------------------------

    /**
     * {@inheritDoc}
     */
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        /* Inflate the menu; this adds items to the action bar if it is present */
        getMenuInflater().inflate(R.menu.activity_main, menu);
        return true;
    }

    /**
     * <p>Send a message using the data in the {@link View}</p>
     *
     * @param view - the {@link View} object representing the state of the view when the message is sent
     */
    public void sendMessage(View view) {
        Intent intent = new Intent(this, DisplayMessageActivity.class);
        EditText editText = (EditText) view.findViewById(R.id.edit_message);
        String message = editText.getText().toString(); // This is the guilty line
        intent.putExtra(EXTRA_MESSAGE, message);
        startActivity(intent);
    }

    /**
     * {@inheritDoc}
     */
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }

}

My activity_main.xml:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity"
    android:orientation="horizontal" >

    <EditText android:id="@+id/edit_message"
        android:layout_weight="1"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:hint="@string/edit_message" />

    <Button 
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/button_send" 
        android:onClick="sendMessage" />

</LinearLayout>

and the LogCat output:

12-21 10:02:32.210: E/Trace(621): error opening trace file: No such file or directory (2)
12-21 10:02:32.250: W/ActivityThread(621): Application com.example.myfirstapp is waiting for the debugger on port 8100...
12-21 10:02:32.270: I/System.out(621): Sending WAIT chunk
12-21 10:02:32.280: I/dalvikvm(621): Debugger is active
12-21 10:02:32.480: I/System.out(621): Debugger has connected
12-21 10:02:32.480: I/System.out(621): waiting for debugger to settle...
12-21 10:02:32.680: I/System.out(621): waiting for debugger to settle...
12-21 10:02:32.889: I/System.out(621): waiting for debugger to settle...
12-21 10:02:33.091: I/System.out(621): waiting for debugger to settle...
12-21 10:02:33.290: I/System.out(621): waiting for debugger to settle...
12-21 10:02:33.534: I/System.out(621): waiting for debugger to settle...
12-21 10:02:33.796: I/System.out(621): waiting for debugger to settle...
12-21 10:02:33.990: I/System.out(621): waiting for debugger to settle...
12-21 10:02:34.204: I/System.out(621): debugger has settled (1353)
12-21 10:02:35.429: D/gralloc_goldfish(621): Emulator without GPU emulation detected.
12-21 10:05:11.510: I/Choreographer(621): Skipped 94 frames!  The application may be doing too much work on its main thread.
12-21 10:05:13.850: I/Choreographer(621): Skipped 35 frames!  The application may be doing too much work on its main thread.
12-21 10:05:15.571: I/Choreographer(621): Skipped 38 frames!  The application may be doing too much work on its main thread.
12-21 10:06:53.724: D/AndroidRuntime(621): Shutting down VM
12-21 10:06:53.724: W/dalvikvm(621): threadid=1: thread exiting with uncaught exception (group=0x40a13300)
12-21 10:06:53.840: E/AndroidRuntime(621): FATAL EXCEPTION: main
12-21 10:06:53.840: E/AndroidRuntime(621): java.lang.IllegalStateException: Could not execute method of the activity
12-21 10:06:53.840: E/AndroidRuntime(621):  at android.view.View$1.onClick(View.java:3591)
12-21 10:06:53.840: E/AndroidRuntime(621):  at android.view.View.performClick(View.java:4084)
12-21 10:06:53.840: E/AndroidRuntime(621):  at android.view.View$PerformClick.run(View.java:16966)
12-21 10:06:53.840: E/AndroidRuntime(621):  at android.os.Handler.handleCallback(Handler.java:615)
12-21 10:06:53.840: E/AndroidRuntime(621):  at android.os.Handler.dispatchMessage(Handler.java:92)
12-21 10:06:53.840: E/AndroidRuntime(621):  at android.os.Looper.loop(Looper.java:137)
12-21 10:06:53.840: E/AndroidRuntime(621):  at android.app.ActivityThread.main(ActivityThread.java:4745)
12-21 10:06:53.840: E/AndroidRuntime(621):  at java.lang.reflect.Method.invokeNative(Native Method)
12-21 10:06:53.840: E/AndroidRuntime(621):  at java.lang.reflect.Method.invoke(Method.java:511)
12-21 10:06:53.840: E/AndroidRuntime(621):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
12-21 10:06:53.840: E/AndroidRuntime(621):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
12-21 10:06:53.840: E/AndroidRuntime(621):  at dalvik.system.NativeStart.main(Native Method)
12-21 10:06:53.840: E/AndroidRuntime(621): Caused by: java.lang.reflect.InvocationTargetException
12-21 10:06:53.840: E/AndroidRuntime(621):  at java.lang.reflect.Method.invokeNative(Native Method)
12-21 10:06:53.840: E/AndroidRuntime(621):  at java.lang.reflect.Method.invoke(Method.java:511)
12-21 10:06:53.840: E/AndroidRuntime(621):  at android.view.View$1.onClick(View.java:3586)
12-21 10:06:53.840: E/AndroidRuntime(621):  ... 11 more
12-21 10:06:53.840: E/AndroidRuntime(621): Caused by: java.lang.NullPointerException
12-21 10:06:53.840: E/AndroidRuntime(621):  at com.example.myfirstapp.MainActivity.sendMessage(MainActivity.java:61)
12-21 10:06:53.840: E/AndroidRuntime(621):  ... 14 more

score 5 · Accepted Answer · answered Dec 21 '12 at 09:13

5

Change this line

EditText editText = (EditText) view.findViewById(R.id.edit_message);

to

EditText editText = (EditText)findViewById(R.id.edit_message);

answered Dec 21 '12 at 09:13

Chirag

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1

It won't let me for another 43 seconds – m0rv4i Dec 21 '12 at 09:25

score 0 · Answer 2 · answered Dec 21 '12 at 09:15

here in sendMessage method, view parameter is the Button being clicked, and EditText is not child of this view, so you need to call findViewById from the activity content view, which you call by

EditText editText = (EditText) findViewById(R.id.edit_message);

Android - NullPointerException on EditText field

2 Answers2