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引言：通过上一篇的论述，我们知道gradle脚本是如假包换的groovy代码，但是这个groovy代码是运行在他的上下文环境里面的，学名叫语义模型。这一篇我们就来看看他的语义模型到底是什么。

gradle下载安装

gradle的下载安装并没有什么出乎意料的东西，进入他的官网（http://gradle.org/），下载gradle压缩包，解压，配置bin路径到Path即可。

我安装在c盘下，进入目录C:\gradle-2.4\docs\userguide，打开userguide.pdf文件，这个就是gradle的官方帮助文档。

gradle 初涉

我们试下第六章的hello world，创建一个文件夹，在里面创建一个文件build.gradle.输入以下的代码：

task hello {
    doLast {
        println ‘Hello world!‘
    }
}

命令行输入gradle -q hello，打印 Hello world!

看文档对这个Demo的说明：We call this build.gradle file a build script, although strictly speaking it is a build configuration script, as we will see later. The build script defines a project and its tasks.按照帮助文档的内容，大概可以猜测出来，每一个build.gradle文件都可以实例一个project类。用谷歌搜索下gradle和project就可以应证这个判断。

我们打开C:\gradle-2.4\docs\javadoc\org\gradle\api找到Project.html，这里可以找到更多的信息。

This interface is the main API you use to interact with Gradle from your build file.         你的build.gradle就是来配置这个接口的！看下文档对Project生命周期的

project生命周期

There is a one-to-one relationship between a Project and a "build.gradle" file. During build initialisation, Gradle assembles a Project object for each project which is to participate in the build, as follows:

• Create a Settings instance for the build.        首先创建一个Settings的实例。
• Evaluate the "settings.gradle" script, if present, against the Settings object to configure it.        如果当前目录有settings.gradle,那么用这个文件来配置Settings实例。
• Use the configured Settings object to create the hierarchy of Project instances.        用Settings实例来创建Project的继承关系。
• Finally, evaluate each Project by executing its "build.gradle" file, if present, against the project. The projects are evaluated in breadth-wise order, such that a project is evaluated before its child projects. This order can be overridden by calling evaluationDependsOnChildren() or by adding an explicit evaluation dependency usingevaluationDependsOn(String).        最后，如果项目中存在build.gradle就通过它来执行每个Project。项目中，项目分别依次横向执行，以此子项目一定在父项目之后执行。这个规则可以通过调用evaluationdependsonchildren()或加入一个明确的依赖usingevaluationdependson（String）。

至此，project中所有的方法，理论上我们在gradle脚本中都可以调用。我们试着编译一个java方法，打开帮助文档chaper 7。

创建一个build.gradle文件，和一个src文件。build.gradle文件中输入：

apply plugin:‘java‘

src中创建com/test/Main.java,输入java代码：

package com.test;

public class Main {

	public static void main(String[] args) {
		System.out.println("hello gradle!");
	}
}

在命令行中输入 gradle build

13051041@CNHQ-13051041T /cygdrive/d/gradleDemo/javaDemo
# gradle build
:compileJava UP-TO-DATE
:processResources UP-TO-DATE
:classes UP-TO-DATE
:jar
:assemble
:compileTestJava UP-TO-DATE
:processTestResources UP-TO-DATE
:testClasses UP-TO-DATE
:test UP-TO-DATE
:check UP-TO-DATE
:build

BUILD SUCCESSFUL

Total time: 2.562 secs

已经可以编译成功了！我们先看下apply是个什么函数，在project的帮助文档中搜索下，发现这是另外一个接口PluginAware提供的方法，详情如下：

apply
void apply(Map<String,?> options)
Applies a plugin or script, using the given options provided as a map. Does nothing if the plugin has already been applied.
The given map is applied as a series of method calls to a newly created ObjectConfigurationAction. That is, each key in the map is expected to be the name of a method ObjectConfigurationAction and the value to be compatible arguments to that method.

The following options are available:

from: A script to apply. Accepts any path supported by Project.uri(Object).
plugin: The id or implementation class of the plugin to apply.
to: The target delegate object or objects. The default is this plugin aware object. Use this to configure objects other than this object.
Parameters:
options - the options to use to configure and ObjectConfigurationAction before “executing” it

看的出是导入了一个叫java的插件，project中对插件的定义是：插件可以用于模块化和重用项目配置。

gradle脚本运行环境分析（gradle的语义模型）

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原文地址：http://www.cnblogs.com/chenjie0949/p/4757702.html