Android Studio：错误Execution failed for task ':app:compileDebugNdk'

在Android Studio2.2.3中开发时，因为引用了第三方.so库，在Project --> app --> src --> main 下新建了jniLibs文件夹，并将.so复制在下面，编译时出错如下：

Error:Execution failed for task ':app:compileDebugNdk'.
> Error: Your project contains C++ files but it is not using a supported native build system.
Consider using CMake or ndk-build integration with the stable Android Gradle plugin:
 https://developer.android.com/studio/projects/add-native-code.html
or use the experimental plugin:
 http://tools.android.com/tech-docs/new-build-system/gradle-experimental.

解决方法：

在Project --> app --> build.gradle文件中android {}中添加如下代码后，同步Gradle文件即可。

android {      ......    sourceSets.main {        jniLibs.srcDir 'libs'        jni.srcDirs = []    }}