Learn the basics of Gradle build scripts and the basics of Groovy language.

Learn the basics of Gradle build scripts and the basics of Groovy language.

1. What is Gradle

Definition: Gradle It uses a domain-specific language based on Groovy to declare project settings.

1.1 APK Build

Compile resources, compile code, and sign apk.

1.2 Gradle execution command

./gradlew clean

./gradlew projects

./gradlew tasks

1.3 Gradle version changes, upgrades and downgrades

Command line operation: ./gradlew wrapper --gradle-version desired version number

Or directly modify gradle-wrapper.properties in the project directory

2. How to run groovy programs in Android Studio

Refer to this guy’s blog below:

https://blog.csdn.net/Gdeer/article/details/83062523

2.1 Simple syntax

class MyGroovy {
    
    
    static void main(String[] args) {
    
    
        
        //变量
        int a = 10
        def b = 10
        println "a=$a"
        println "b=$b"
        //字符串
        String str = "111aaaaaa1"
        String str2 = str.toUpperCase()
        println "str=$str"
        println "str2=$str2"
        //集合
        def array = [1, 2, 2, 2]
        println "array $array"
        array.add(222)
        array.each {
    
     println it }
        //map
        def map = ["name": "1221", "age": 100]
        println "$map"
        println "${map["age"]}"
        //循环
        for (i in 0..<10) {
    
    
            println i
        }

        hello(1111)
    }
    //方法
    def hello(String name){
    
    
        println name
    }
}

2.2 Advanced syntax

DSL, closures, classes

Closure (function expression): an open anonymous block of code that can accept parameters, have a return value, and can also be assigned to variables.

{[ params -> ] statements }

class MyGroovy {
    
    
    static void main(String[] args) {
    
    
        def c = {
    
    
            println 111
        }
        def c2 = {
    
    
            it -> println it
        }
        c2(123)
        def c3 = {
    
    
            name1, name2 ->
                {
    
    
                    println name1
                    println name2
                }
        }
        c3(111, 222)

        def list = [1, 2, 3, 4, 5]
        list.each {
    
    
            it ->
                println it
        }
    }
}

DSL：

class MyGroovy {
    
    
    static void main(String[] args) {
    
    
        def android = {
    
    
            compileSdkVersion 27
            defaultConfig {
    
    
                versionName "1.0"
            }
        }
        Android a = new Android()
        //将闭包与具体对象关联起来
        android.dehydrate = a
        android.call()
        println ("$a")
    }
}

class DefaultConfig {
    
    
    private String versionName

    def versionName(String versionName) {
    
    
        this.versionName = versionName
    }

    @Override
    String toString() {
    
    
        return "DefaultConfig{ versionName = $versionName}"
    }
}

class Android {
    
    
    private int compileSdkVersion
    private DefaultConfig defaultConfig

    Android() {
    
    
        this.defaultConfig = new DefaultConfig()
    }

    def compileSdkVersion(int compileSdkVersion) {
    
    
        this.compileSdkVersion = compileSdkVersion
    }

    def defaultConfig(Closure closure) {
    
    
        closure.setDelegate(defaultConfig)
        closure.call()
    }

    @Override
    String toString() {
    
    
        return "Android{ compileSdkVersion = $compileSdkVersion,defaultConfig = $defaultConfig }"
    }
}

2.3 Gradle builds common script files

settings.gradle

build.gradle

gradle.properties

2.4 Life cycle, sequence

initialization phase

configuration phase

Execution phase

Test in settings.gradle

gradle.addBuildListener(new BuildListener() {
    
    
    @Override
    void settingsEvaluated(Settings settings) {
    
    
        println "Initialization phase completed"
    }

    @Override
    void projectsLoaded(Gradle gradle) {
    
    
        println "During the configuration loading process"
    }

    @Override
    void projectsEvaluated(Gradle gradle) {
    
    
        println "configuration complete"
    }

    @Override
    void buildFinished(BuildResult buildResult) {
    
    
        println "End of construction"
    }
})

2.4 Important directories, Gradle tasks

Initialization phase - root project

Configuration phase - project

Execution phase - task