Android Studio的Library項目一般默認是生成aar文件，如何生成jar文件，其實也不難

兩步完成

1 在build.gradle中加入以下代碼

// This is the actual solution, as in http://stackoverflow.com/a/19037807/1002054task clearJar(type: Delete) {    delete 'build/libs/myCompiledLibrary.jar'}task makeJar(type: Copy) {    from('build/intermediates/bundles/release/')    into('build/libs/')    include('classes.jar')    rename ('classes.jar', 'myCompiledLibrary.jar')}makeJar.dependsOn(clearJar, build)
注意:classes.jar文件的路徑不一定是'build/intermediates/bundles/release/'，這個根據實際情況來修改
2 在Android Studio的Terminal中運行gradlew makeJar