Question

am getting this exception:

java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{business.premium/business.premium.Problemio}: 
java.lang.ClassNotFoundException: business.premium.Problemio
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1880)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1981)
        at android.app.ActivityThread.access$600(ActivityThread.java:123)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1147)
        at android.os.Handler.dispatchMessage(Handler.java:99)
        at android.os.Looper.loop(Looper.java:137)
        at android.app.ActivityThread.main(ActivityThread.java:4424)
        at java.lang.reflect.Method.invokeNative(Native Method)
        at java.lang.reflect.Method.invoke(Method.java:511)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
        at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.ClassNotFoundException: business.premium.Problemio
        at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:61)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:501)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:461)
        at android.app.Instrumentation.newActivity(Instrumentation.java:1023)
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1871)
        ... 11 more
java.lang.ClassNotFoundException: business.premium.Problemio
        at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:61)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:501)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:461)
        at android.app.Instrumentation.newActivity(Instrumentation.java:1023)
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1871)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1981)
        at android.app.ActivityThread.access$600(ActivityThread.java:123)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1147)
        at android.os.Handler.dispatchMessage(Handler.java:99)
        at android.os.Looper.loop(Looper.java:137)
        at android.app.ActivityThread.main(ActivityThread.java:4424)
        at java.lang.reflect.Method.invokeNative(Native Method)
        at java.lang.reflect.Method.invoke(Method.java:511)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
        at dalvik.system.NativeStart.main(Native Method)

it says that class is not there, but it IS there. I tried to configure things in my project’s build path, but not too sure what to tweak there.

And here is how I start my Manifest file:

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

    <supports-screens  android:largeScreens="true"   android:normalScreens="true"  android:smallScreens="true"/> 

    <uses-sdk android:minSdkVersion="4" android:targetSdkVersion="15"/>
    <uses-permission android:name="android.permission.INTERNET" />

    <application
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name" 
        android:theme="@style/CustomTheme" 
        android:name="MyApplication"
        android:debuggable="true">
        <activity
            android:name=".Problemio"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

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

Any thoughts on how to solve this, or what to look into? Thanks!

Answer 1

Its because you specified the “android:name” attribute in the application node in the manifest file.

Do not use the android:name attribute!

It, misleadingly, does not have anything to do with the name of your app and is actually the name of an extra class to load before loading your application. That’s why you are getting the ClassNotFoundException.

Remove it and it should work:

<application 
    android:icon="@drawable/icon" 
    android:label="@string/app_name" 
    android:description="@string/help_text" >

This answer is taken from: java.lang.ClassNotFoundException on working app