下载并复制你的。jar文件到libs文件夹，然后添加这些行到build.gradle:

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation 'com.google.code.gson:gson:2.3.1'
}

别忘了按“立即同步”

Easy steps to add external library in Android Studio If you are in Android View in project explorer, change it to Project view as below Right click the desired module where you would like to add the external library, then select New > Directroy and name it as 'libs' Now copy the blah_blah.jar into the 'libs' folder Right click the blah_blah.jar, Then select 'Add as Library..'. This will automatically add and entry in build.gradle as compile files('libs/blah_blah.jar') and sync the gradle. And you are done Please Note : If you are using 3rd party libraries then it is better to use dependencies where Gradle script automatically downloads the JAR and the dependency JAR when gradle script run. Ex : compile 'com.google.android.gms:play-services-ads:9.4.0' Read more about Gradle Dependency Mangement

在Mac OS X上:

将jar添加为库(将jar拖到libs，右键单击添加为库) 在build.grade中添加compile语句 安装gradle v1.6(使用自制软件) Brew install gradle gradle - v 如果不是v1.6，升级homebrew Gradle清洁(重建android不工作)

这让我理清了思路。

所有这些解决方案都过时了。现在在Android Studio中非常简单:

文件>新模块…

下一个屏幕看起来很奇怪，就像你选择了一些小部件或其他东西，但保留了它 在第一张图片和下面滚动，找到“Import JAR or .AAR Package”

然后从文件菜单中选择项目结构。从打开的窗口中选择app，然后选择依赖项，然后按绿色加号按钮，选择模块依赖项，然后选择导入的模块，然后按OK

下面是将本地jar文件作为库添加到模块的说明:

Create a 'libs' folder in the top level of the module directory (the same directory that contains the 'src' directory) In the build.gradle file add the following so that your dependencies closure has: dependencies { // ... other dependencies compile files('libs/<your jar's name here>') } Android Studio should have already setup a gradlew wrapper. From the command line, navigate to the top level of your project (the directory that has a gradlew file). Run ./gradlew assemble. This should compile the project with the library. You may need to fix errors in your build.gradle file as necessary. In order to have Android Studio recognize the local jar files as libraries for support while coding in the IDE, you need to take a few more steps: 4.1. Right click on the module in the left hand panel and choose Open Library Settings. 4.2. On the left panel of the dialog, choose Libraries. 4.3. Click the + sign above the panel second from the left -> Java 4.4. Select your local jar and add it to the project. You may need to run the above ./gradlew command one more time

从网站下载图书馆文件 从窗口复制 从项目资源管理器粘贴到lib文件夹 Ctrl+Alt+Shift+S打开项目结构 选择Dependencies选项卡，使用+添加文件 工具栏通过按钮将项目与gradle文件同步

这解决了我的问题。试试，如果有人想知道更多细节，请告诉我。