Android Gradle使用总结（1）

Gradle是一款优秀的构建系统工具，它的DSL(领域特定语言)基于Groovy实现，可以方便地通过代码控制这些DSL来达到构建的目的。

注：执行gradle命令时，默认加载当前目录下的build.gradle文件，亦可以通过-b 指定要加载的执行文件，如： gradlew -b ./app/build.gradle assemble

Gradle常用基础

1、记得使用帮助

（1）查看所有可执行的任务（Tasks）

gradlew tasks

Gradle会以分组的方式列出task列表，比如构建类的 assemable，帮助类的 help等

------------------------------------------------------------
All tasks runnable from root project
------------------------------------------------------------

Android tasks
-------------
androidDependencies - Displays the Android dependencies of the project.
signingReport - Displays the signing info for each variant.
sourceSets - Prints out all the source sets defined in this project.

Build tasks
-----------
assemble - Assembles all variants of all applications and secondary packages.
assembleAndroidTest - Assembles all the Test applications.
assembleDebug - Assembles all Debug builds.
assembleRelease - Assembles all Release builds.
build - Assembles and tests this project.
buildDependents - Assembles and tests this project and all projects that depend on it.
buildNeeded - Assembles and tests this project and all projects it depends on.
bundleDebug - Creates all Debug bundles.
bundleRelease - Creates all Release bundles.
clean - Deletes the build directory.
cleanBuildCache - Deletes the build cache directory.
compileDebugAndroidTestSources
compileDebugSources
compileDebugUnitTestSources
compileReleaseSources
compileReleaseUnitTestSources

Build Setup tasks
-----------------
init - Initializes a new Gradle build.
wrapper - Generates Gradle wrapper files.

Cleanup tasks
-------------
lintFix - Runs lint on all variants and applies any safe suggestions to the source code.

Help tasks
----------
buildEnvironment - Displays all buildscript dependencies declared in root project 'tapeView'.
components - Displays the components produced by root project 'tapeView'. [incubating]
dependencies - Displays all dependencies declared in root project 'tapeView'.
dependencyInsight - Displays the insight into a specific dependency in root project 'tapeView'.
dependentComponents - Displays the dependent components of components in root project 'tapeView'. [incubating]
help - Displays a help message.
model - Displays the configuration model of root project 'tapeView'. [incubating]
projects - Displays the sub-projects of root project 'tapeView'.
properties - Displays the properties of root project 'tapeView'.
tasks - Displays the tasks runnable from root project 'tapeView' (some of the displayed tasks may belong to subprojects).

Install tasks
-------------
installDebug - Installs the Debug build.
installDebugAndroidTest - Installs the android (on device) tests for the Debug build.
installRelease - Installs the Release build.
uninstallAll - Uninstall all applications.
uninstallDebug - Uninstalls the Debug build.
uninstallDebugAndroidTest - Uninstalls the android (on device) tests for the Debug build.
uninstallRelease - Uninstalls the Release build.

Verification tasks
------------------
check - Runs all checks.
connectedAndroidTest - Installs and runs instrumentation tests for all flavors on connected devices.
connectedCheck - Runs all device checks on currently connected devices.
connectedDebugAndroidTest - Installs and runs the tests for debug on connected devices.
deviceAndroidTest - Installs and runs instrumentation tests using all Device Providers.
deviceCheck - Runs all device checks using Device Providers and Test Servers.
lint - Runs lint on all variants.
lintDebug - Runs lint on the Debug build.
lintRelease - Runs lint on the Release build.
lintVitalRelease - Runs lint on just the fatal issues in the release build.
test - Run unit tests for all variants.
testDebugUnitTest - Run unit tests for the debug build.
testReleaseUnitTest - Run unit tests for the release build.

To see all tasks and more detail, run gradle tasks --all

To see more detail about a task, run gradle help --task <task>

BUILD SUCCESSFUL in 18s
1 actionable task: 1 executed
复制代码

（2）Gradle Help任务

gradle内置的help任务，可以了解每一个Task的使用帮助，用法是 gradlew help --task <taskName> 如： gradlew help --task assemable

2、强制刷新依赖

gradlew --refresh-dependencies assemable

3、多任务执行

只需按顺序以空格分开即可，如 gradlew clean jar ，先执行clean再执行生成jar

4、自定义属性

自定义属性具有更广泛的作用域，可以跨Project，跨Task访问。 只要能访问这些属性所属的对象 ，那么这些属性就可以被访问到。

apply plugin: "java"

ext.age = 18 //自定义一个属性

//自定义多个属性
ext{
	phone = '020'
	address = ''

	dep = [android : "androidan"] //map
}


sourceSets.all{
	ext.resourcesDir = null
}

sourceSets {
	main{
		resourcesDir="main/res"
	}
	test{
		resourcesDir="test/res"
	}
}

task customProperty{
	doLast{
		println "age: ${age}"
		println "phone: $phone"
		println "address: $address"
		println "android: ${dep.android}"

		sourceSets.each{
			println"${it.name}'s resourcesDir is: ${it.resourcesDir}"
		}
	}
	
}
复制代码

5、任务的禁用和开启

任务禁用时，当执行到该任务，会skip掉

task task1{
    doLast{
        println 'xxx'
    }
}

task1.enabled = false; //false:禁用，true:开启
复制代码

6、任务的onlyif 断言

任务有一个onlyIf方法，接收一个闭包作为参数，如果该闭包返回true，则该任务执行，否则跳过

以键值对的形式添加属性：-PK=V，中间不能有空格 ，如： gradle -Pbuild_apps=shoufa build

final String BUILD_APPS_ALL="all";
final String BUILD_APPS_SHOUFA="shoufa";
final String BUILD_APPS_EXCLUDE_SHOUFA="exclude_shoufa";

task QQRelease{
	doLast{
		println "QQRelease"
	}
    
}
task BaiduRelease{
	doLast{
		println "BaiduRelease"
	}
   
}

task build{
	group BasePlugin.BUILD_GROUP
	description '打渠道包'
	dependsOn QQRelease,BaiduRelease
}

QQRelease.onlyIf{
	if (project.hasProperty('build_apps')) {
		Object buildApps = project.property("build_apps")
		if (BUILD_APPS_SHOUFA.equals(buildApps)) {
			return false
		}
	}
	return true;
}

//gradle -Pbuild_apps=shoufa build; //以键值对的形式添加属性：-PK=V，中间不能有空格
复制代码

7、脚本即代码，代码也是脚本

虽然Gradle是个脚本文件，但写的依旧是代码，Groovy是兼容 Java 的，能灵活实现很多功能。如，给生成的apk以当前时间命名：

def buildTime(){
    def date = new Date()
    def formattedDate = data.format('yyyyMMdd')
    return formattedDate
}
复制代码

Groovy基础

1、字符串

单引号和双引号都能定义字符串。区别在于，单引号表示纯粹的字符串常量，而双引号具有运算能力。 如:

def name = "John"
println '单引号${name}' //输出: 单引号${name}
println "双引号${name}"  //输出: 双引号John
println "双引号$name"   //输出: 双引号John
复制代码

一个美元符号紧接着一对花括号，花括号里放表达式，如 ${name} ，当只有一个变量时，可以省略花括号，如 $name ;

2、集合

（1）List

def nums = [1,2,3,4] //定义arrayList
println nums[1]  //下标索引访问
nums.each{
    println it //forEach,其中it变量为正在迭代的元素
}
复制代码

（2）Map

def map = ['width':1024,'height':768] //定义map
println map['width'] //访问
println map.height //访问
map.each{
    println "Key:${it.key},Value:$it.value" //forEach,被变量的是Map.Entry
}
复制代码

（3）方法

• 括号是可以忽略的

method1(2,3) //
method1 2,3 //可忽略括号，
def method1(int a,int b){
    println a+b
}
复制代码

• return 是可以不写的，最后一句代码作为其返回值

def method2(int a,int b){
    if(a>b){
        a //即return a;
    }else {
        b //即return b;
    }
}
复制代码

• 代码块/方法是可以作为参数传递的

//呆板写法
nums.each({println it})

//格式化一些
nums.each({
    println it
})

//Groovy中，如果方法的最后一个参数是 闭包，则可以放到方法外面
nums.each(){
    println it
}

//然后省略括号，则变成常见的样式
nums.each{
    println it
}

//多参数调用
eachMap{k,v->
    println "$k is $v"
}
复制代码

• JavaBean,可以很容易地访问和修改属性值，而不用通过getter/setter，因Groovy内部已帮我们搞定好。

def Person p = new Person()
println "name is $p.name" //输出null
p.name = "John" 
println "name is $p.name" //输出John

class Person {
    private String name
}
复制代码

• 闭包委托 Groovy的闭包有thisObject、owner和delegate三个属性，一般是thisObject>owner>delegate，但可以修改delegate。一般指定delegate为当前it，这样就可以在闭包内对该it进行配置，或调用其方法。

task delegate{
	doLast{
		person{
			name = "cap" //在闭包内对该it进行配置
			age = 20    //在闭包内对该it进行配置
			dumpPersion()  //在闭包内对该it调用其方法
		}
	}


}
def dumpPersion(){
	println "project delegate"
}


class Person{
	private String name
	private int age 

	def dumpPersion(){
		println "name:${name};age:${age}"
	}
}

def person(Closure<Person> closure){
	Person p = new Person()
	closure.delegate = p //设置委托
	closure.setResolveStrategy(Closure.DELEGATE_FIRST)//设置委托优先
	closure(p)
}
复制代码

Gradle 插件

1、Java Gradle 的sourceSets常用属性

sourceSet，即源代码集合（Android的 buildTypes 和这个类似），用来描述和管理源代码和资源存放等功能。提供有sourceSets{}闭包放配置和生成sourceSet，如：

sourceSets{
    main{
        //在这里可以对main sourceSet进行配置
        
        java{
            srcDir 'src/java' //更改了java源代码存放目录，默认是 src/main/java
        }
        resources{
            srcDir 'src/resources' //更改了资源文件存放目录，默认是 src/main/resources
        }
    }
    vip{
        //生成了新的 vip sourceSet
    }
}
复制代码

SourceSet常用属性：

2、Android Gradle插件分类和三个sourceSet

Android Gradle插件的分类是根据Anroid工程的属性分类的，在Android中，有3类：

1. App应用工程插件id: com.android.application
2. Library库工程插件id: com.android.library
3. Test测试工程插件id: com.android.test

注：src目录下的androidTest，main，test分别是3个sourceSet，分别对应，Android单元测试代码，Android app主代码和资源，普通单元测试代码。 在main中，特有AndroidManifest.xml和res这两个Android特有的，用于描述Android App 配置和资源文件。