NoClassDefFoundError for code in an Java library on Android

android noclassdeffounderror
kjoelbro picture kjoelbro · Dec 30, 2011 · Viewed 109.1k times · Source

I am experiencing an error quite often among my users. The app crashes during startup. When the MainActivity is supposed to be loaded the VM apparently cannot find the class. I cannot figure out why. The architecture of the app is that there is a common project that both my free and pro version are using. Don't know if it is relevant. See the stack trace below. Any thoughts?

java.lang.NoClassDefFoundError: com.android.common.MainActivity
at com.mycompany.myapp.Splash.onCreate(Splash.java:23)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1615)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1667)
at android.app.ActivityThread.access$1500(ActivityThread.java:117)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:935)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:130)
at android.app.ActivityThread.main(ActivityThread.java:3687)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:507)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:842)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:600)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.ClassNotFoundException: com.android.common.MainActivity in loader     dalvik.system.PathClassLoader[/system/framework/com.google.android.maps.jar:/data/app/com.android.pro-1.apk]

Edit: Thanks for the comment below, Richard. Now I have changed com.android.Splash to something else. It wasn't the real classname anyway. My bad...!

Answer

Sabo picture Sabo · Oct 3, 2012

I had the same issue, I did the following to fix the problem.

  1. Go to "Properties" of the project.
  2. Select "Java Build Path"
  3. Select "Order and Export" Tab
  4. You should see the selected project's "src" and "gen" paths and dependencies here.
  5. The order how they listed were first "src" and then "gen" path
  6. I switch them, so that "gen" folder is build before the "src"

gen - automated code in project (from dependencies and references)
src - source code in project

There was no need to restart the Eclipse. It just started working.

Honestly I have never tried "Android Tools > Fix Project Properties", sometimes it might be doing the same thing. I do not know, I just did above after seen the error message, thinking something is wrong with the build paths.

Edit

Later on it was not sufficient, I was getting the error again. Then I "checked" all the dependencies listed in that view. Now it works again. So far so good. I will keep this updated if it fails again.

FYI: in my last attempt, I tried "Android Tools > Fix Project Properties", but it didn't work out for me.

Related questions

Android java.lang.NoClassDefFoundError

I have an Android project in eclipse IDE which was working. After some imports and tests, I get the error: java.lang.NoClassDefFoundError. In my project I have two packages: the main one and the second one with some classes. …

Read More
Unable instantiate android.gms.maps.MapFragment

I try to do a demo with google maps android v2 with very simple activity, just copy code from google page: https://developers.google.com/maps/documentation/android/start#adding_the_api_key_to_your_application for activity: package com.…

Read More
Adding Joda Time

I am building an app that uses time. I decided to use Joda time. I am trying to add joda time to my app. I have no experience with adding .jar files to the libs. I followed these steps(see …

Read More