android编译报错Error:Execution failed for task ':app:compileDebugJavaWithJavac'.

Android studio编译时报错：Error:Execution failed for task ':app:compileDebugJavaWithJavac'.

> Failed to create MD5 hash for file 'E:\workspace\smartdevice\Robot\YIShuo_Robot_v0.0.1\app\android_api_3.7.1.1.jar'.

原因：

        找不到E:\workspace\smartdevice\Robot\YIShuo_Robot_v0.0.1\app\android_api_3.7.1.1.jar文件

解决：

     build.gradle Module.app dependencies中compile files('android_api_3.7.1.1.jar')少了libs/

compile files('libs/android_api_3.7.1.1.jar')