in Android, Java

mockable-24-android.jar : Sometime too large

As a TA of the course “Mobile Application App”, I recently run into a problem. The teacher asks students to upload their homework to LATTE, our university’s course management platform. However, the size limit of LATTE platform is 20 MB, and



As Professor Chaturvadi suggests that we’d better stick on Latte for homework submission, I tried to load the apk. Actually, it does work on my AVD. But the thing is, although apk is actually zip, many files are turned into binary. Android Studio 2.2, which is released on 9/19, has a tool to decompile the code. However, I bet none of us want to read decompiled code like this:

If we want to stick on LATTE, we can definitely ask students to remove $rootDir/build/mockable-android-24.jar. The conclusion comes from Android Studio’s document regarding their new build system:


Multiple modules (e.g. app and lib) now share the same mockable android.jar (for unit testing) which is generated only once. Delete $rootDir/build to regenerate it.


They implies the whole build/ directory can be removed.

In a word, we can safely remove it since this file is for Unit Test. Even if we want to do Unit Test (which I assume we won’t do), it can be regenerated automatically.

Source code for generating the mockable jar is here, and here for the gradle task when building. We can see that it generates corresponding mockable jar according to android.jar. It just become too large for API version 24.



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