第六十一章. Gradle 包装器

Gradle Wrapper（下称“包装器”）是启动 Gradle 构建的首选方法。包装器在 Windows 上是一个批处理脚本，而在其他操作系统上是个 shell 脚本。当你通过包装器启动 Gradle 构建时，将自动下载 Gradle 并用于运行构建。
The Gradle Wrapper (henceforth referred to as the “wrapper”) is the preferred way of starting a Gradle build. The wrapper is a batch script on Windows, and a shell script for other operating systems. When you start a Gradle build via the wrapper, Gradle will be automatically downloaded and used to run the build.

你 应该 将包装器纳入版本控制。通过将包装器分发到项目中，任何人都可以在未安装 Gradle 的情况下使用它。更好的效果是能让用户使用这个构建所设计的 Gradle 版本。当然，这对于 连续集成 服务器（即定期构建项目的服务器）也很重要，因为它不需要在服务器上进行配置。
The wrapper is something you should check into version control. By distributing the wrapper with your project, anyone can work with it without needing to install Gradle beforehand. Even better, users of the build are guaranteed to use the version of Gradle that the build was designed to work with. Of course, this is also great for continuous integration servers (i.e. servers that regularly build your project) as it requires no configuration on the server.

你可以通过在你的构建脚本中添加一个 Wrapper 任务并配置，然后执行它。
You install the wrapper into your project by adding and configuring a Wrapper task in your build script, and then executing it.

task wrapper(type: Wrapper) {
    gradleVersion = '1.4'
}

执行之后，你会在你的项目目录中发现以下新生成或更新的文件（在使用的 wrapper 任务为默认配置的情况下）。
After such an execution you find the following new or updated files in your project directory (in case the default configuration of the wrapper task is used).

simple/
  gradlew
  gradlew.bat
  gradle/wrapper/
    gradle-wrapper.jar
    gradle-wrapper.properties

所有这些文件都 应该 提交到版本控制系统中。这只需要做一次。在将这些文件添加到项目之后，应该使用所添加的 gradlew 命令来构建项目。gradlew 命令可以和 gradle 命令完全一样地使用。
All of these files should be submitted to your version control system. This only needs to be done once. After these files have been added to the project, the project should then be built with the added gradlew command. The gradlew command can be used exactly the same way as the gradle command.

如果要切换到新版本的 Gradle，不用重新运行包装器任务，只要修改 gradle-wrapper.properties 文件中的相应属性就可以了。但是，如果有例如 gradle 包装器功能提升的情况的话，你还是需要重新生成包装器文件。
If you want to switch to a new version of Gradle you don't need to rerun the wrapper task. It is good enough to change the respective entry in the gradle-wrapper.properties file. But if there is for example an improvement in the gradle-wrapper functionality you need to regenerate the wrapper files.