将多个jar打成一个jar，适用于SDK

task makeJar(type: Jar, dependsOn: "assembleRelease") {
    doFirst {
        delete fileTree(BUILD_LIBS_PATH) {
            include JAR_NAME_PREFIX + "**.jar"
        }
    }
    archiveName = 'kkcoresdk.jar'
    from('build/intermediates/classes/release')
    from(project.zipTree("libs/app_kookong_data.jar"))
    from(project.zipTree("libs/app_service.jar"))
    from(project.zipTree("libs/xutils.jar"))

    destinationDir = file('build/libs')
//    exclude('com/kookong/sdk/BuildConfig.class')
    exclude('com/kookong/sdk/BuildConfig\$*.class')
    exclude('**/R.class')
    exclude('**/R\$*.class')
}

1.定义打包jar的task

2.设置打包class的目录

3.编译所依赖的jar

4.指定输出路径