There was a requirement of my work. It requires me to integrated my current project with Facebook SDK for measuring. However this came into my sights.
Jar mismatch! Fix your dependencies
The fact is that Both my project and my library project which the former refers to have used android-support-v4.jar. However I realize the two android-support-v4.jar are different after making the md5 hash. My solution: I use the android-support-v4.jar in my project as the right one. And then replace the one in Facebook SDK with my project one. And then it works. But my question remains; why it asks me for fix the dependencies to use the same lib jar file? I guess android will keep only one file for all the references so this will ask developers to make all the same lib all the same. Sorry for the codeless post.