了解 Gradle“任务”语法

Question

我很难理解 Gradle“任务”语法。

我按照howto定义了build.gradle，用gradle构建了一个Angular4/SpringBoots项目。

build.gradle 包含多个 task 块：

// add our development build NpmTask named buildClientDev
task buildClientDev(type: NpmTask, dependsOn: 'npmInstall') {
    group = 'build'
    description = 'Compile client side folder for development'
    args = ['run', 'buildDev']
}


task buildClient(type: NpmTask, dependsOn: 'npmInstall') {
    group = 'build'
    description = "Compile client side folder for production"
    args = ['run', 'build']
}

// setup watcher on this ng build to link to our overall java development build.
task buildClientWatch(type: NpmTask, dependsOn: 'npmInstall') {
    group = 'application'
    description = "Build and watches the client side assets for rebuilding"
    args = ['run', 'buildWatch']
}

应用程序通过 gradle 启动，通过执行 Gradle 命令./gradlew bootRun

问题：

• 谁定义了这些任务块的语法？我应用的插件之一？
• 是buildDev, build, buildWatch NPM 还是 Gradle 命令？
• 如果这些是 NPM 命令 - Gradle 的 gradlew bootrun 命令的连接在哪里？ Gradle 怎么知道它们应该在gradlew bootrun 之后执行？

---

完整的 build.gradle：

buildscript {
    ext {
        springBootVersion = '2.0.0.RELEASE'
    }
    repositories {
        jcenter()
        mavenCentral()
        maven {
            url "https://plugins.gradle.org/m2/"
        }
    }
    dependencies {
        classpath("org.springframework.boot:spring-boot-gradle-plugin:${springBootVersion}")
        classpath "com.moowork.gradle:gradle-node-plugin:1.1.1"
    }
}


apply plugin: 'idea'
apply plugin: 'eclipse'
apply plugin: 'org.springframework.boot'
apply plugin: 'io.spring.dependency-management'
apply plugin: 'java'
// enable building wars: gradlew BootWar
apply plugin: 'war'

// fuilding frontend with npm
apply plugin: "com.moowork.node"

// add our development build NpmTask named buildClientDev
task buildClientDev(type: NpmTask, dependsOn: 'npmInstall') {
    group = 'build'
    description = 'Compile client side folder for development'
    args = ['run', 'buildDev']
}


task buildClient(type: NpmTask, dependsOn: 'npmInstall') {
    group = 'build'
    description = "Compile client side folder for production"
    args = ['run', 'build']
}

// setup watcher on this ng build to link to our overall java development build.
task buildClientWatch(type: NpmTask, dependsOn: 'npmInstall') {
    group = 'application'
    description = "Build and watches the client side assets for rebuilding"
    args = ['run', 'buildWatch']
}

bootRun.dependsOn(buildClientDev)
jar.dependsOn(buildClient)

npm_run_build.inputs.dir new File(projectDir, "frontend")
npm_run_build.outputs.dir new File(projectDir, "build/dist")

group = 'de.webapp.spring'
version = '0.0.1-SNAPSHOT'
sourceCompatibility = 1.8
targetCompatibility = 1.8

repositories {
    mavenCentral()
    maven { url "http://repo.spring.io/snapshot" }
    maven { url "http://repo.spring.io/milestone" }
    maven { url 'https://repo.spring.io/libs-snapshot' }
}


dependencies {
    // makes the web application startable
    compile("org.springframework.boot:spring-boot-starter")
    compile("org.springframework.boot:spring-boot-starter-web")
    testCompile('org.springframework.boot:spring-boot-starter-test')

    //data
    compile("org.springframework.boot:spring-boot-starter-data-jpa")
    compile("org.springframework.boot:spring-boot-starter-data-rest")

    // RepositoryRestConfigurerAdapter
    compile "org.springframework.data:spring-data-rest-core"
    compile "org.springframework.data:spring-data-rest-webmvc"
    compile "org.springframework:spring-context"

    // enables HAL browser
    compile "org.springframework.data:spring-data-rest-hal-browser"

    // entity requirements
    compile "com.h2database:h2"
    compile "javax.xml.bind:jaxb-api"
}

更新：

执行链如下，在做gradlew bootRun时

• 分级。 gradlew bootRun 命令 >
• Gradle“moowork”插件。 buildClientDev 任务。因为bootRun.dependsOn(buildClientDev)。 >
• NPM。 “构建开发”任务。因为args = ['run', 'buildDev']>
• 角 CLI。构建。因为在 package.json 中：buildDev": "ng build"

gradlew bootRun 的有向依赖图如下所示：

gradlew tasktree bootRun

> Task :taskTree

------------------------------------------------------------
Root project
------------------------------------------------------------

:bootRun
+--- :buildClientDev
|    +--- :npmInstall
|    |    \--- :npmSetup
|    |         \--- :nodeSetup
|    \--- :npmSetup
|         \--- :nodeSetup
\--- :classes
     +--- :compileJava
     \--- :processResources

Answer 1

谁定义了这些任务块的语法？我应用的插件之一？

任务块中可用的属性和方法由任务的“类型”定义。在这种情况下，它是来自com.moowork.node 插件的NpmTask

是 buildDev、build、buildWatch NPM 还是 Gradle 命令？

它们是 gradle 模型中的任务，类型为 NpmTask（来自 com.moowork.node 插件）

如果这些是 NPM 命令 - Gradle 的 gradlew bootrun 命令的连接在哪里？ Gradle 怎么知道，它们应该在 gradlew bootrun 之后执行？

同样，bootRun 不是核心 Gradle 任务，它是由 org.springframework.boot 插件添加的。它们在 Gradle 的 DAG 中连接在一起。我可以在您的 build.gradle 中看到两个 dependsOn 声明，它们将它们连接在一起

• bootRun.dependsOn(buildClientDev)
• task buildClientDev(type: NpmTask, dependsOn: 'npmInstall')

如果你想可视化 DAG，我建议你添加 task-tree 插件

plugins {
    id "com.dorongold.task-tree" version "1.3"
}

然后你可以运行

./gradlew taskTree bootRun

你会得到一个类似于下面的任务树（注意：这个例子是一个完全不同的任务树）

:build
+---- :assemble
|    \--- :jar
|         \--- :classes
|              +--- :compileJava
|              \--- :processResources
\--- :check
     \--- :test
          +--- :classes
          |    +--- :compileJava
          |    \--- :processResources
          \--- :testClasses
               +--- :compileTestJava
               |    \--- :classes
               |         +--- :compileJava
               |         \--- :processResources
               \--- :processTestResources