java.lang.NoClassDefFoundError: Could not initialize class XXX

Question

public class PropHolder {
  public static Properties prop;

  static {
    //code for loading properties from file
  }
}

// Referencing the class somewhere else:
Pr         


        

Answer 1

I had the same exception, this is how I solved the problem:

Preconditions:

1. Junit class (and test), that extended another class.

2. ApplicationContext initialized using spring, that init the project.

3. The Application context was initialized in @Before method

Solution:

Init the application context from @BeforeClass method, since the parent class also required some classes that were initialized from within the application context.

Hope this will help.

Answer 2

I had the same exception - but only while running in debug mode, this is how I solved the problem (after 3 whole days): in the build.gradle i had : "multiDexEnabled true" set in the defaultConfig section.

        defaultConfig {
    applicationId "com.xxx.yyy"
    minSdkVersion 15
    targetSdkVersion 28
    versionCode 5123
    versionName "5123"
    // Enabling multidex support.
    multiDexEnabled true
}

but apparently this wasn't enough. but when i changed:

public class MyAppClass  extends Application 

to:

public class MyAppClass  extends MultiDexApplication 

this solved it. hope this will help someone

Answer 3

If you're working on an Android project, make sure you aren't calling any static methods on any Android classes. I'm only using JUnit + Mockito, so maybe some other frameworks might help you avoid the problem altogether, I'm not sure.

My problem was calling Uri.parse(uriString) as part of a static initializer for a unit test. The Uri class is an Android API, which is why the unit test build couldn't find it. I changed this value to null instead and everything went back to normal.

Answer 4

As mentioned above, this could be a number of things. In my case I had a statically initialized variable which relied on a missing entry in my properties file. Added the missing entry to the properties file and the problem was solved.