为Android Studio编写自定义Gradle插件的教程

Google已经建议Android开发全部转向Android Studio开发，Android Studio 是使用gradle编译、打包的，那么问题来了，gradle可是有一堆东西...，为了彻底了解gradle，今天就来学习下如何写自己的gradle插件（当然插件源码是使用groovy写的），先看如下代码目录：

如上图所示，plugin目录是插件源码目录，sample是用来测试插件的。

1、在目录plugin/src/main/groovy/com/micky/gradle/下新建插件类MyCustomPlugin.groovy

package com.micky.gradle; 
 
import org.gradle.api.*; 
 
class MyCustomPlugin implements Plugin { 
  void apply(Project project) { 
    project.task('myTask') << { 
      println "Hi this is micky's plugin" 
    } 
  } 
} 

看看Plugin的源码，其实就是一接口

public interface Plugin { 
  /** 
   * Apply this plugin to the given target object. 
   * 
   * @param target The target object 
   */ 
  void apply(T target); 
} 

2、在目录plugin/src/main/resources/META-INF/gradle-plugins/下创建文件com.micky.mycustom.properties用来指定插件实现类

implementation-class=com.micky.gradle.MyCustomPlugin 

 

   特别注意下：文件名“com.micky.mycustom”即是以后我们在使用插件时的apply plugin 'java' 的java，这里我也是折腾了半天才得出的结果，坑啊。

3、一般情况下，我们还需要指定插件项目名称，在plugin目录下新建settings.gradle

rootProject.name='gradle-micky' 

 

4、万事具备，就差编译了，编译需要在plugin目录下新建build.gradle

apply plugin: 'groovy' 
apply plugin: 'maven' 
 
dependencies { 
  compile gradleApi() 
  compile localGroovy() 
} 
 
repositories { 
  mavenCentral() 
} 
 
group='com.micky' 
version='1.0.0' 
 
uploadArchives { 
  repositories { 
    mavenDeployer { 
      repository(url: uri('../repo')) 
    } 
  } 
} 

在这个脚本里使用groovy插件编译groovy源码，声明gradleAPI作为即时编译依赖，apply plugin: 'maven' 是用来创建一个插件jar文件并且存储在本地maven库里，本地maven库即我们在脚本里创建的"../repo"目录
执行命令:  

gradle uploadArchives

5、以上4个步骤已经编译插件并上传到了本地库中，接下来就看看怎么使用插件，在sample目录下，新建build.gradle

buildscript { 
  repositories { 
    maven { 
      url uri('../repo') 
    } 
  } 
 
  dependencies { 
    classpath group: 'com.micky', 
      name: 'gradle-micky', 
      version: '1.0.0' 
  } 
} 
 
apply plugin: 'com.micky.mycustom' 

6、执行命令

myTask即我们在MyCustomPlugin.groovy代码中创建的任务。

7、自定义Task

（1）copy一份改名CustomPluginTask

在plugin\src\main\groovy\com\micky\gradle目录创建源文件 MyCustomTask.groovy

package com.micky.gradle; 
 
import org.gradle.api.DefaultTask 
import org.gradle.api.tasks.TaskAction 
 
class MyCustomTask extends DefaultTask { 
  @TaskAction 
  void output() { 
    println "Hello this is my custom task output" 
  } 
} 

（2）修改MyCustomPlugin.groovy

package com.micky.gradle; 
 
import org.gradle.api.*; 
 
class MyCustomPlugin implements Plugin { 
  void apply(Project project) { 
    project.task('customTask', type: MyCustomTask) 
  } 
} 

（3）修改plugin目录下的build.gradle，修改版本号

apply plugin: 'groovy' 
apply plugin: 'maven' 
 
dependencies { 
  compile gradleApi() 
  compile localGroovy() 
} 
 
repositories { 
  mavenCentral() 
} 
 
group='com.micky' 
version='1.0.1' 
 
uploadArchives { 
  repositories { 
    mavenDeployer { 
      repository(url: uri('../repo')) 
    } 
  } 
} 

执行gradle uploadArchives 编译插件包
        
（4）sample目录下的build.gradle

buildscript { 
  repositories { 
    maven { 
      url uri('../repo') 
    } 
  } 
 
  dependencies { 
    classpath group: 'com.micky', 
      name: 'gradle-micky', 
      version: '1.0.1' 
  } 
} 
apply plugin: 'com.micky.mycustom'  

执行gradle customTask 结果如下：

8、向Plugin Task 传递参数
（1）拷贝一份上面的代码，改名为CustomPluginTaskWithParam，修改plugin\src\main\groovy\com\micky\gradle\MyCustomPlugin.groovy

package com.micky.gradle; 
 
import org.gradle.api.*; 
 
class MyCustomPluginExtension { 
  def message = "From MyCustomPluginExtention" 
  def sender = "MyCustomPluin" 
} 
 
class MyCustomPlugin implements Plugin { 
  void apply(Project project) { 
    project.extensions.create('myArgs', MyCustomPluginExtension) 
    project.task('customTask', type: MyCustomTask) 
  } 
} 

（2）修改plugin\src\main\groovy\com\micky\gradle\MyCustomTask.groovy

package com.micky.gradle; 
 
import org.gradle.api.DefaultTask 
import org.gradle.api.tasks.TaskAction 
 
class MyCustomTask extends DefaultTask { 
  @TaskAction 
  void output() { 
    println "Sender is ${project.myArgs.sender},\nmessage: ${project.myArgs.message}" 
  } 
} 

       
（3）修改plugin/build.gradle

apply plugin: 'groovy' 
apply plugin: 'maven' 
 
dependencies { 
  compile gradleApi() 
  compile localGroovy() 
} 
 
repositories { 
  mavenCentral() 
} 
 
group='com.micky' 
version='1.0.2' 
 
uploadArchives { 
  repositories { 
    mavenDeployer { 
      repository(url: uri('../repo')) 
    } 
  } 
} 

        执行gradle uploadArchives 编译插件包    

（4）修改sample/build.gradle

buildscript { 
  repositories { 
    maven { 
      url uri('../repo') 
    } 
  } 
 
  dependencies { 
    classpath group: 'com.micky', 
      name: 'gradle-micky', 
      version: '1.0.2' 
  } 
} 
 
apply plugin: 'com.micky.mycustom' 

（5）执行gradle customTask，结果如下：

（6）在gradle文件配置参数

buildscript { 
  repositories { 
    maven { 
      url uri('../repo') 
    } 
  } 
 
  dependencies { 
    classpath group: 'com.micky', 
      name: 'gradle-micky', 
      version: '1.0.2' 
  } 
} 
 
apply plugin: 'com.micky.mycustom' 
 
myArgs { 
  sender='Micky Liu' 
  message='Gradle is so simple.' 
} 

 
（7）执行gradle customTask，结果如下：

8、向Plugin Task 传递嵌套试复杂参数
（1）拷贝一份上面的代码，改名为CustomPluginTaskWithNestParam，修改plugin\src\main\groovy\com\micky\gradle\MyCustomPlugin.groovy

package com.micky.gradle; 
 
import org.gradle.api.*; 
 
class MyNestPluginExtension { 
  def receiver = "Kate Zhou" 
  def email = "[email protected]" 
} 
 
class MyCustomPluginExtension { 
  def message = "From MyCustomPluginExtention" 
  def sender = "MyCustomPluin" 
} 
 
class MyCustomPlugin implements Plugin { 
  void apply(Project project) { 
    project.extensions.create('myArgs', MyCustomPluginExtension) 
    project.myArgs.extensions.create('nestArgs', MyNestPluginExtension) 
    project.task('customTask', type: MyCustomTask) 
  } 
} 

（2）修改MyCustomPlugin.groovy

package com.micky.gradle; 
 
import org.gradle.api.DefaultTask 
import org.gradle.api.tasks.TaskAction 
 
class MyCustomTask extends DefaultTask { 
  @TaskAction 
  void output() { 
    println "Sender is ${project.myArgs.sender} \nmessage: ${project.myArgs.message}" 
    println "Receiver is ${project.myArgs.nestArgs.receiver} \nemail: ${project.myArgs.nestArgs.email}" 
  } 
} 

 

（3）修改plugin/build.gradle

apply plugin: 'groovy' 
apply plugin: 'maven' 
 
dependencies { 
  compile gradleApi() 
  compile localGroovy() 
} 
 
repositories { 
  mavenCentral() 
} 
 
group='com.micky' 
version='1.0.3' 
 
uploadArchives { 
  repositories { 
    mavenDeployer { 
      repository(url: uri('../repo')) 
    } 
  } 
} 

（4）执行gradle uploadArchives 编译插件包
（5）修改sample/build.gradle

buildscript { 
  repositories { 
    maven { 
      url uri('../repo') 
    } 
  } 
 
  dependencies { 
    classpath group: 'com.micky', 
      name: 'gradle-micky', 
      version: '1.0.3' 
  } 
} 
 
apply plugin: 'com.micky.mycustom' 
 
myArgs { 
  sender='Micky Liu' 
  message='Gradle is so simple.' 
} 

          
（6）执行执行gradle customTask，结果如下：

（7）在gradle文件配置参数

buildscript { 
  repositories { 
    maven { 
      url uri('../repo') 
    } 
  } 
 
  dependencies { 
    classpath group: 'com.micky', 
      name: 'gradle-micky', 
      version: '1.0.3' 
  } 
} 
 
apply plugin: 'com.micky.mycustom' 
 
myArgs { 
  sender='Micky Liu' 
  message='Gradle is so simple.' 
  nestArgs { 
    receiver='David Chen' 
    email='[email protected]' 
  } 
 
} 

（8）执行gradle customTask，结果如下：

  源码地址：https://github.com/mickyliu945/GradleCustomPlugin