Thanks for your advice! I try with that and it works right now!
I delete the java-diff.jar and rebuild the module that you have show above .
finally, it success!
So the problem is that the package java-diff.jar in maven central repository is different with it in the xwiki respository!
Because of the network speed,After I follow the link that you had gave above and configure , then I rebuild source code, but i can not download the package java-diff.jar at the beginning. So I change the repository to maven repository and it works !
Now it is clear! The java-diff.jar package in the maven central repository and xwiki respository is different ! Did someone change the package?I have try two pakcage of different version, its category is same!
Finally, thanks for your help！
Respect ! 
