Getting an exception when app starts

Question

I am writing a program that calls someone when a button is pressed. However, whenever I start the app, it crashes, before even pressing the button. This is the code:

package com.test;

import android.app.Activity;
import android.content.ActivityNotFoundException;
import android.os.Bundle;
import android.widget.*;
import android.view.*;
import android.view.View.OnClickListener;
import android.content.Intent;
import android.net.Uri;
import android.util.Log;

public class MainActivity extends Activity {

    private OnClickListener mButtonListener = new OnClickListener() {
        public void onClick(View v) {
            try {
                Intent callIntent = new Intent(Intent.ACTION_CALL);
                callIntent.setData(Uri.parse("tel:123456789"));
                startActivity(callIntent);
            }

            catch (ActivityNotFoundException activityException) {
                 Log.e("Test", "Call failed");
            }
        }
    };

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        Button button = (Button)findViewById(R.id.button);
        button.setOnClickListener(mButtonListener);
    }
};

And here is my layout:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
    <Button android:layout_width="wrap_content" android:id="@+id/button" android:layout_height="wrap_content" android:text="@string/callme" />
</LinearLayout>

Here is the error I'm getting (from logcat)

D/AndroidRuntime(  337): >>>>>> AndroidRuntime START com.android.internal.os.RuntimeInit <<<<<<
D/AndroidRuntime(  337): CheckJNI is ON
D/AndroidRuntime(  337): Calling main entry com.android.commands.am.Am
I/ActivityManager(   78): Starting: Intent { act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] flg=0x10000000 cmp=com.test/.MainActivity } from pid 337
I/ActivityManager(   78): Start proc com.test for activity com.test/.MainActivity: pid=345 uid=10035 gids={1015}
D/AndroidRuntime(  337): Shutting down VM
I/AndroidRuntime(  337): NOTE: attach of thread 'Binder Thread #3' failed
D/dalvikvm(  337): GC_CONCURRENT freed 102K, 69% free 319K/1024K, external 0K/0K, paused 2ms+2ms
D/dalvikvm(  337): Debugger has detached; object registry had 1 entries
I/ARMAssembler(   78): generated scanline__00000177:03515104_00001002_00000000 [ 87 ipp] (110 ins) at [0x4456d6f0:0x4456d8a8] in 715314 ns
D/AndroidRuntime(  345): Shutting down VM
W/dalvikvm(  345): threadid=1: thread exiting with uncaught exception (group=0x40015560)
E/AndroidRuntime(  345): FATAL EXCEPTION: main
E/AndroidRuntime(  345): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.test/com.test.MainActivity}: java.lang.ClassCastException: android.widget.TextView
E/AndroidRuntime(  345):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1647)
E/AndroidRuntime(  345):    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1663)
E/AndroidRuntime(  345):    at android.app.ActivityThread.access$1500(ActivityThread.java:117)
E/AndroidRuntime(  345):    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:931)
E/AndroidRuntime(  345):    at android.os.Handler.dispatchMessage(Handler.java:99)
E/AndroidRuntime(  345):    at android.os.Looper.loop(Looper.java:123)
E/AndroidRuntime(  345):    at android.app.ActivityThread.main(ActivityThread.java:3683)
E/AndroidRuntime(  345):    at java.lang.reflect.Method.invokeNative(Native Method)
E/AndroidRuntime(  345):    at java.lang.reflect.Method.invoke(Method.java:507)
E/AndroidRuntime(  345):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
E/AndroidRuntime(  345):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
E/AndroidRuntime(  345):    at dalvik.system.NativeStart.main(Native Method)
E/AndroidRuntime(  345): Caused by: java.lang.ClassCastException: android.widget.TextView
E/AndroidRuntime(  345):    at com.test.MainActivity.onCreate(MainActivity.java:34)
E/AndroidRuntime(  345):    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
E/AndroidRuntime(  345):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1611)
E/AndroidRuntime(  345):    ... 11 more
W/ActivityManager(   78):   Force finishing activity com.test/.MainActivity
W/ActivityManager(   78): Activity pause timeout for HistoryRecord{4059b300 com.test/.MainActivity}
W/ActivityManager(   78): Activity destroy timeout for HistoryRecord{4059b300 com.test/.MainActivity}
I/Process (  345): Sending signal. PID: 345 SIG: 9
I/ActivityManager(   78): Process com.test (pid 345) has died.
W/InputManagerService(   78): Window already focused, ignoring focus gain of: com.android.internal.view.IInputMethodClient$Stub$Proxy@405cdc18

Thanks in advance.

You'll need to give us the exact Exception message. You can find it in the LogCat output. — Lukas Knuth
@Gareth: I'm assume it's just a typo in your code example but the closing brace of your Activity is followed by a semi-colon which shouldn't be there. — Squonk
I removed it and it didn't make a difference. I actually am used to C programming. Also, I saw it somewhere in an example and thought it might fix something. It goes without saying, it didn't. — Serentty
Maybe it's just a case of the generated R class being out of sync with the XML (the reference to a TextView seems truly weird), if you're using Eclipse, try cleaning your project. — dmon
Thank you! It's working now. I've got another error when trying to call, but I'll figure that out separately. — Serentty

Vuki Limani Vuki Limani · Accepted Answer · 2016-02-10T16:12:26

Try to put your button like in the code below and you would get your desired output. Hope it helps!

public class MainActivity extends Activity {

private OnClickListener mButtonListener = new OnClickListener() {
    public void onClick(View v) {
        try {
            Intent callIntent = new Intent(Intent.ACTION_CALL);
            callIntent.setData(Uri.parse("tel:123456789"));
            startActivity(callIntent);
        }

        catch (ActivityNotFoundException activityException) {
            Log.e("Test", "Call failed");
        }
    }
};

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    Button button = (Button) findViewById(R.id.button);
    try {

        button.setOnClickListener(mButtonListener);

    } catch (IOException e) {
        // TODO Auto-generated catch block
        System.out.println("Your Crash :" + e);
        e.printStackTrace();

    }

}
};

Getting an exception when app starts

4 Answers