I got java.lang.ClassNotFoundException when i try to start activity of another application

[sam liya]

I tried with below example

Activity example

when i run the example and click the button to call other activity it givess me below exception

07-16 10:35:47.150: D/AndroidRuntime(332): Shutting down VM
07-16 10:35:47.150: W/dalvikvm(332): threadid=1: thread exiting with uncaught exception (group=0x40015560)
07-16 10:35:47.170: E/AndroidRuntime(332): FATAL EXCEPTION: main
07-16 10:35:47.170: E/AndroidRuntime(332): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.hmkcode.android/com.hmkcode.android.another.app.AnotherActivity}: java.lang.ClassNotFoundException: com.hmkcode.android.another.app.AnotherActivity in loader dalvik.system.PathClassLoader[/data/app/com.hmkcode.android-1.apk]
07-16 10:35:47.170: E/AndroidRuntime(332): 	at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1569)
07-16 10:35:47.170: E/AndroidRuntime(332): 	at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1663)
07-16 10:35:47.170: E/AndroidRuntime(332): 	at android.app.ActivityThread.access$1500(ActivityThread.java:117)
07-16 10:35:47.170: E/AndroidRuntime(332): 	at android.app.ActivityThread$H.handleMessage(ActivityThread.java:931)
07-16 10:35:47.170: E/AndroidRuntime(332): 	at android.os.Handler.dispatchMessage(Handler.java:99)
07-16 10:35:47.170: E/AndroidRuntime(332): 	at android.os.Looper.loop(Looper.java:123)
07-16 10:35:47.170: E/AndroidRuntime(332): 	at android.app.ActivityThread.main(ActivityThread.java:3683)
07-16 10:35:47.170: E/AndroidRuntime(332): 	at java.lang.reflect.Method.invokeNative(Native Method)
07-16 10:35:47.170: E/AndroidRuntime(332): 	at java.lang.reflect.Method.invoke(Method.java:507)
07-16 10:35:47.170: E/AndroidRuntime(332): 	at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
07-16 10:35:47.170: E/AndroidRuntime(332): 	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
07-16 10:35:47.170: E/AndroidRuntime(332): 	at dalvik.system.NativeStart.main(Native Method)
07-16 10:35:47.170: E/AndroidRuntime(332): Caused by: java.lang.ClassNotFoundException: com.hmkcode.android.another.app.AnotherActivity in loader dalvik.system.PathClassLoader[/data/app/com.hmkcode.android-1.apk]
07-16 10:35:47.170: E/AndroidRuntime(332): 	at dalvik.system.PathClassLoader.findClass(PathClassLoader.java:240)
07-16 10:35:47.170: E/AndroidRuntime(332): 	at java.lang.ClassLoader.loadClass(ClassLoader.java:551)
07-16 10:35:47.170: E/AndroidRuntime(332): 	at java.lang.ClassLoader.loadClass(ClassLoader.java:511)
07-16 10:35:47.170: E/AndroidRuntime(332): 	at android.app.Instrumentation.newActivity(Instrumentation.java:1021)
07-16 10:35:47.170: E/AndroidRuntime(332): 	at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1561)
07-16 10:35:47.170: E/AndroidRuntime(332): 	... 11 more

i run using real phone as well as emulator,but i got same results.when i tried with second app it works fine both emulator and device.

[Ulf Dittmer]

Does the app include that class?

[sam liya]

of course ULF.

[Ulf Dittmer]

Apparently Android doesn't think so, so it's a justified question. The next question, just as obvious: is it correctly declared as being an Activity in the manifest?

Have you tried making it the launch activity - does that work? If you haven't tried, that should be the next step.

[sam liya]

this is my first app main class

package com.hmkcode.android;

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

public class MainActivity extends Activity implements OnClickListener {

	Button btnStartAnotherActivity;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);

		btnStartAnotherActivity = (Button) findViewById(R.id.btnStartAnotherActivity);

		btnStartAnotherActivity.setOnClickListener(this);
	}

	@Override
	public void onClick(View view) {

		// calling an activity using <intent-filter> action name
		Intent inent = new Intent(
				"com.hmkcode.android.another.app.ANOTHER_ACTIVITY");

		startActivity(inent);
	}

}

this is main app layout file

<RelativeLayout 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"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".MainActivity" >
 
    <TextView
        android:id="@+id/textView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/hello_world" />
 
    <Button
        android:id="@+id/btnStartAnotherActivity"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/textView1"
        android:layout_marginTop="26dp"
        android:layout_centerHorizontal="true"
        android:text="Start Another App Activity" />
 
</RelativeLayout>

this is main app manifest file

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.hmkcode.android"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="10"
        android:targetSdkVersion="10" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name="com.hmkcode.android.MainActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity
            android:name="com.hmkcode.android.another.app.AnotherActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="com.hmkcode.android.another.app.ANOTHER_ACTIVITY" />

                <category android:name="android.intent.category.DEFAULT" />
            </intent-filter>
        </activity>
    </application>

</manifest>

this is second app main class

package com.hmkcode.android.another.app;

import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;

public class AnotherActivity extends Activity {

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);
	}

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

}

this is second app layout file

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >
 
    <TextView
        android:id="@+id/textView1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:gravity="center_horizontal"
        android:text="Another App Activity"
        android:textAppearance="?android:attr/textAppearanceLarge" />
 
</LinearLayout>

this is second app manifest file

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.hmkcode.android.another.app"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="10"
        android:targetSdkVersion="10" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name="com.hmkcode.android.another.app.AnotherActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

[Ulf Dittmer]

I'm confused - you have two apps that have this activity? The one trying to launch it, and another one that has just that activity? So are you trying to launch a different app, or a different activity within the same app?

[sam liya]

as in the example below it tries to start an activity in a another application.
http://hmkcode.com/android-start-another-activity-of-another-application/

[Ulf Dittmer]

You changed the intent-filter action - that is not how it is in the article. So the only activity that reacts to "com.hmkcode.android.another.app.ANOTHER_ACTIVITY" is the first app - which you said is not what you want. Why does the first app even have AnotherActivity in its manifest?