第六十一章. Gradle包装器

Gradle 包装器（下称“包装器”）是启动 Gradle 构建的首选方法。这个包装器是Windows上的一个批处理脚本和以及用于其他操作系统的shell 脚本。当你通过包装器启动 Gradle 构建时，Gradle 将被自动下载并用于运行这个构建。
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.

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. 甚至还有更好的效果，能保证用户在构建中所使用的Gradle版本一致。当然，也方便用于 持续集成 服务器（即有规律地构建你的项目的服务器），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及配置一个 Wrapper 任务，然后执行它来把包装器安装到你的项目中。
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'
}

在这样执行之后，你会在你的项目目录中发现以下新生成的或更新的文件（在所使用的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 被提交到你的版本控制系统中。这只需要做一次。在这些文件都已经被添加到项目中之后，这个项目以后应该使用所添加的 gradlew命令进行构建。这个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.

如果你想要切换到一个新的Gradle版本，你不需要重新运行wrapper任务。只需要修改gradle wrapper.properties文件中的相应属性就够了。但如果有例如gradle包装器功能的提升的话，你还是需要重新生成包装器的文件。
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.