Paypal Mobile Express Checkout Library Sample App Gives Me Noclassdeffounderror Exception

I'm testing the sample app for Mobile Express Checkout Library with Android. I'm getting java.lang.NoClassDefFoundError: com.paypal.android.pizza.ResultDelegate The error is on th

Solution 1:

There are only three reasons you will ever get this error:

1. The class genuinely doesn't exist. If you are using code from an official example and getting this, make sure you have the latest build of the library
2. You have not added the jar to your build path. To fix this, right click on the jar in Eclipse, and do Build Path ► Add to Build Path.
3. Your jar is not in the /libs folder. This happens when you have added the jar to the build path, but newer versions of ADT need it to be in /libs. Put it there and it will automatically be added to the build path. If it isn't, try doing a Clean build via ant clean or Project ► Clean in eclipse.

Mostly, such errors occur because newer versions of the ADT require all external jars to be in the libs folder.

By looking at the project you linked to, I can see the paypal jar in the project root. Instead, try moving it into a /libs folder. This should solve your problem.

Solution 2:

I think you have not exported library jar from the configure build path section of eclipse.

Solution 3:

create libs directory in project's directory and add move PayPal_MECL.jar to /libs. goto project properties and remove existing PayPal_MECL entry from libraries