Unable to execute dex: Multiple dex files define---一个莫名的bug

运行时报错：

[2016-07-07 16:26:57 - Dex Loader] Unable to execute dex: Multiple dex files define Lcom/alibaba/fastjson/JSONStreamAware;
[2016-07-07 16:26:57 - YoungHeart2.9] Conversion to Dalvik format failed: Unable to execute dex: Multiple dex files define Lcom/alibaba/fastjson/JSONStreamAware;

 

原因：

本项目自身导入了一个jar库，在它依赖的另一个项目里面导入了同一个库，所以报错。。。删掉一个即可