Gradle系列之从init.gradle提及

从maven提及

用过maven的开发都知道，在maven里一些信息能够定义在全局的配置文件中，好比把一些仓库信息定义在用户目录/.m2/setting.xml文件中，这样就不用每一个项目都配置这些相同的配置了。对于Andorid开发者来讲，使用gradle比使用maven更常见，在开发中说不定你会在每个项目中配置一遍公司的仓库地址，定义一些相同的配置，那么在gradle中有没有相似maven的这么一个配置文件能够定义一些全局信息呢？

答案固然是有，那就是init.gradle。

init.gradle的做用

先来简单介绍一下init.gradle这个文件的做用。

• 它能够用来创建公司内部的配置,如定义公司内部的仓库地址。
• 它能够用来配置一些全局属性,好比配置持续集成服务器的地址等配置。
• 它能够用来提供构建所须要的用户的我的信息,如仓库或数据库的用户名和密码。
• 它能够用来定义开发者机器的环境,好比定义jdk安装在什么位置，android sdk安装在什么位置等等。
• 最重要的功能之一，它能够用来注册一些监听器。好比监听Gradle事件的发生，作一些额外的操做，例如须要对某个项目构建前和构建后作一些操做，又例如对项目的依赖作检测，检测是否含有snapshot包，在release构建中通常来讲是禁止依赖snapshot包的，因此这时候就能够扔出一个异常。
• 重定向日志。咱们能够将gradle默认的日志进行重定向，甚至咱们能够不输出默认日志，自定义如何输出gradle产生的日志信息。

init.gradle的加载顺序

再来讲说init.gradle文件的加载顺序（不必定命名为init.gradle）。Gradle会依次对一些目录进行检测，按照优先级加载这些目录下的文件，若是一个目录下有多个文件被找到，则按照英文字母的顺序依次加载。加载优先级以下：

• 经过 -I 或者 –init-script 参数在构建开始时指定路径，如
gradle --init-script init.gradle clean

gradle --I init.gradle assembleDebug

• 加载USER_HOME/.gradle/init.gradle文件
• 加载USER_HOME/.gradle/init.d/目录下的以.gradle结尾的文件
• 加载GRADLE_HOME/init.d/目录下的以.gradle结尾的文件

那么USER_HOME和GRADLE_HOME能够怎么获得呢，其实USER_HOME通常来讲就是当前用户目录下的.gradle目录，而GRADLE_HOME目录通常来讲是gradle的可执行目录，若是你配置了环境变量，且你使用的是环境变量中的可执行文件，则这个目录会执向你配置了环境变量的目录，好比，我配置了gradle的环境变量指向/Library/gradle，这两个目录在我电脑上的值为:

gradleHomeDir:/Library/gradle gradleUserHomeDir:/Users/lizhangqu/.gradle

 

可是若是我使用项目中的gradlew去执行任务，则这两个值为

gradleHomeDir:/Users/lizhangqu/.gradle/wrapper/dists/gradle-2.10-all/a4w5fzrkeut1ox71xslb49gst/gradle-2.10 gradleUserHomeDir:/Users/lizhangqu/.gradle

 

咱们能够在init.gradle中使用gradle实例来得到这两个目录，甚至能够得到gradle的版本，以及gradle启动时所携带的参数。具体脚本以下：

//gradle的可执行目录 gradle.println "gradleHomeDir:${gradle.gradleHomeDir}" //gradle的用户目录,用于缓存一些下载好的资源,编译好的构建脚本等 gradle.println "gradleUserHomeDir:${gradle.gradleUserHomeDir}" //gradle的版本号 gradle.println "gradleVersion:${gradle.gradleVersion}" //gralde当前构建的启动参数 gradle.println "startParameter:${gradle.startParameter}"

 

在init.gradle使用三方库

若是咱们须要在init.gradle中使用第三方库的功能，好比我须要使用apache的commons-math库中的某个函数，则可使用initscript定义仓库地址，而后将依赖加入，以下脚本：

initscript {
    //定义init.gradle所须要的仓库地址 repositories { jcenter() mavenCentral() mavenLocal() }  //加入依赖 dependencies { classpath 'org.apache.commons:commons-math:2.0' } } //使用函数 println org.apache.commons.math.fraction.Fraction.ONE_FIFTH.multiply(2)

 

以上代码会输出2/5

在init.gradle中定义全局的仓库

在公司中，我所见到的仓库的定义都是定义在每个项目中，没有一个全局的仓库配置，这样显得有点冗余，而在init.gradle中就能够定义一个公司的仓库地址，以后全部的gradle项目均可以使用这个仓库。而且对于一些实时在改变的库，咱们能够定义其全局的更新策略（虽然这个策略在个人电脑上一直没有生效，但这是gradle官方标准的作法，即便用cacheChangingModulesFor属性，将其时间设为0，没有生效显然是一个bug）。

//init.gralde能够配置一些全局的配置，好比仓库的地址等 import java.util.concurrent.TimeUnit allprojects { Project project -> buildscript { repositories { maven { url "htttp://url/to/maven" } jcenter() mavenCentral() mavenLocal() } } repositories { maven { url "htttp://url/to/maven" } jcenter() mavenCentral() mavenLocal() } configurations.all { resolutionStrategy { // cache dynamic versions for 10 minutes cacheDynamicVersionsFor 10 * 60, TimeUnit.SECONDS // don't cache changing modules at all cacheChangingModulesFor 0, TimeUnit.SECONDS } } } 

 

在init.gradle中自定义插件并使用

在咱们的项目中，咱们会使用apply plugin来引用一些插件来加强一些功能，固然在init.gradle也能够这么作，咱们就之前面定义公司的仓库和依赖的更新策略来作演示，将其修改成一个插件而后使用。以下：

//对于一些仓库的全局定义，也可使用插件的方式定义，如 apply plugin: EnterpriseRepositoryPlugin class EnterpriseRepositoryPlugin implements Plugin<Gradle> { private static String REPOSITORY_URL = "htttp://url/to/maven" void apply(Gradle gradle) { gradle.allprojects { project -> project.buildscript { repositories { maven { url REPOSITORY_URL } jcenter() mavenCentral() mavenLocal() } dependencies { //能够定义全局的android gradle插件 classpath 'com.android.tools.build:gradle:2.1.2' } } project.repositories { maven { url REPOSITORY_URL } jcenter() mavenCentral() mavenLocal() } project.configurations.all { resolutionStrategy { // cache dynamic versions for 10 minutes cacheDynamicVersionsFor 10 * 60, TimeUnit.SECONDS // don't cache changing modules at all cacheChangingModulesFor 0, TimeUnit.SECONDS } } } } }

 

使用init.gradle重写日志

默认的若是我使用gradle assembleDebug来执行构建，控制台会输出一系列的log，相似下面的内容

./gradlew --I init.gradle assembleDebug
Incremental java compilation is an incubating feature.
:app:preBuild UP-TO-DATE :app:preDebugBuild UP-TO-DATE :app:checkDebugManifest :app:preReleaseBuild UP-TO-DATE :app:prepareComAndroidSupportAnimatedVectorDrawable2411Library :app:prepareComAndroidSupportAppcompatV72411Library :app:prepareComAndroidSupportSupportV42411Library :app:prepareComAndroidSupportSupportVectorDrawable2411Library :app:prepareDebugDependencies :app:compileDebugAidl :app:compileDebugRenderscript :app:generateDebugBuildConfig :app:mergeDebugShaders :app:compileDebugShaders :app:generateDebugAssets :app:mergeDebugAssets :app:generateDebugResValues UP-TO-DATE :app:generateDebugResources :app:mergeDebugResources :app:processDebugManifest :app:processDebugResources :app:generateDebugSources :app:incrementalDebugJavaCompilationSafeguard :app:compileDebugJavaWithJavac :app:compileDebugJavaWithJavac - is not incremental (e.g. outputs have changed, no previous execution, etc.). :app:compileDebugNdk UP-TO-DATE :app:compileDebugSources :app:prePackageMarkerForDebug :app:transformClassesWithDexForDebug Merged dex #1 (5 defs/15.3KiB) Merged dex #2 (355 defs/574.2KiB) Merged dex #3 (819 defs/997.1KiB) Merged dex #4 (17 defs/48.5KiB) Merged dex #5 (29 defs/89.4KiB) Merged dex #6 (363 defs/280.8KiB) Merged dex #7 (46 defs/7.4KiB) Result is 1634 defs/2438.7KiB. Took 0.5s :app:mergeDebugJniLibFolders :app:transformNative_libsWithMergeJniLibsForDebug :app:processDebugJavaRes UP-TO-DATE :app:transformResourcesWithMergeJavaResForDebug :app:validateDebugSigning :app:packageDebug :app:zipalignDebug :app:assembleDebug BUILD SUCCESSFUL Total time: 29.62 secs 

 

对于这些log，咱们可使用gradle.useLogger()函数从新定义须要输出什么内容。好比咱们让控制台按咱们的意思进行输出，则能够定义一个类，实现BuildListener接口和TaskExecutionListener接口。再调用useLogger函数传入这个类的实例，以下：

gradle.useLogger(new CustomEventLogger()) //自定义的log输出 class CustomEventLogger implements BuildListener, TaskExecutionListener { @Override void buildStarted(Gradle gradle) { println "buildStarted" } @Override void settingsEvaluated(Settings settings) { println "settingsEvaluated" } @Override void projectsLoaded(Gradle gradle) { println "projectsLoaded" } @Override void projectsEvaluated(Gradle gradle) { println "projectsEvaluated" } public void beforeExecute(Task task) { println "beforeExecute:[$task.name]" } public void afterExecute(Task task, TaskState state) { println "afterExecute:[$task.name]" } public void buildFinished(BuildResult result) { println 'buildFinished' if (result.failure != null) { result.failure.printStackTrace() } } }

 

 

以后控制台的输出就会大变样，变成下面的内容

./gradlew --I init.gradle assembleDebug settingsEvaluated projectsLoaded Incremental java compilation is an incubating feature. projectsEvaluated beforeExecute:[preBuild] afterExecute:[preBuild] beforeExecute:[preDebugBuild] afterExecute:[preDebugBuild] beforeExecute:[checkDebugManifest] afterExecute:[checkDebugManifest] beforeExecute:[preReleaseBuild] afterExecute:[preReleaseBuild] beforeExecute:[prepareComAndroidSupportAnimatedVectorDrawable2411Library] afterExecute:[prepareComAndroidSupportAnimatedVectorDrawable2411Library] beforeExecute:[prepareComAndroidSupportAppcompatV72411Library] afterExecute:[prepareComAndroidSupportAppcompatV72411Library] beforeExecute:[prepareComAndroidSupportSupportV42411Library] afterExecute:[prepareComAndroidSupportSupportV42411Library] beforeExecute:[prepareComAndroidSupportSupportVectorDrawable2411Library] afterExecute:[prepareComAndroidSupportSupportVectorDrawable2411Library] beforeExecute:[prepareDebugDependencies] afterExecute:[prepareDebugDependencies] beforeExecute:[compileDebugAidl] afterExecute:[compileDebugAidl] beforeExecute:[compileDebugRenderscript] afterExecute:[compileDebugRenderscript] beforeExecute:[generateDebugBuildConfig] afterExecute:[generateDebugBuildConfig] beforeExecute:[mergeDebugShaders] afterExecute:[mergeDebugShaders] beforeExecute:[compileDebugShaders] afterExecute:[compileDebugShaders] beforeExecute:[generateDebugAssets] afterExecute:[generateDebugAssets] beforeExecute:[mergeDebugAssets] afterExecute:[mergeDebugAssets] beforeExecute:[generateDebugResValues] afterExecute:[generateDebugResValues] beforeExecute:[generateDebugResources] afterExecute:[generateDebugResources] beforeExecute:[mergeDebugResources] afterExecute:[mergeDebugResources] beforeExecute:[processDebugManifest] afterExecute:[processDebugManifest] beforeExecute:[processDebugResources] afterExecute:[processDebugResources] beforeExecute:[generateDebugSources] afterExecute:[generateDebugSources] beforeExecute:[incrementalDebugJavaCompilationSafeguard] afterExecute:[incrementalDebugJavaCompilationSafeguard] beforeExecute:[compileDebugJavaWithJavac] :app:compileDebugJavaWithJavac - is not incremental (e.g. outputs have changed, no previous execution, etc.). afterExecute:[compileDebugJavaWithJavac] beforeExecute:[compileDebugNdk] afterExecute:[compileDebugNdk] beforeExecute:[compileDebugSources] afterExecute:[compileDebugSources] beforeExecute:[prePackageMarkerForDebug] afterExecute:[prePackageMarkerForDebug] beforeExecute:[transformClassesWithDexForDebug] Merged dex #1 (5 defs/15.3KiB) Merged dex #2 (355 defs/574.2KiB) Merged dex #3 (819 defs/997.1KiB) Merged dex #4 (17 defs/48.5KiB) Merged dex #5 (29 defs/89.4KiB) Merged dex #6 (363 defs/280.8KiB) Merged dex #7 (46 defs/7.4KiB) Result is 1634 defs/2438.7KiB. Took 0.7s afterExecute:[transformClassesWithDexForDebug] beforeExecute:[mergeDebugJniLibFolders] afterExecute:[mergeDebugJniLibFolders] beforeExecute:[transformNative_libsWithMergeJniLibsForDebug] afterExecute:[transformNative_libsWithMergeJniLibsForDebug] beforeExecute:[processDebugJavaRes] afterExecute:[processDebugJavaRes] beforeExecute:[transformResourcesWithMergeJavaResForDebug] afterExecute:[transformResourcesWithMergeJavaResForDebug] beforeExecute:[validateDebugSigning] afterExecute:[validateDebugSigning] beforeExecute:[packageDebug] afterExecute:[packageDebug] beforeExecute:[zipalignDebug] afterExecute:[zipalignDebug] beforeExecute:[assembleDebug] afterExecute:[assembleDebug] buildFinished 

 

对于useLogger函数来说，其传入的参数是一个Object类型，咱们让其能够实现任何一个addListener方法传入的参数的接口便可，一旦调用了useLogger方法,默认的gradle事件的日志会被替换,也就是会被替换成咱们自定义的日志输出，而这些接口以下：

• org.gradle.BuildListener
• org.gradle.api.execution.TaskExecutionGraphListener
• org.gradle.api.ProjectEvaluationListener
• org.gradle.api.execution.TaskExecutionListener
• org.gradle.api.execution.TaskActionListener
• org.gradle.api.logging.StandardOutputListener
• org.gradle.api.tasks.testing.TestListener
• org.gradle.api.tasks.testing.TestOutputListener
• org.gradle.api.artifacts.DependencyResolutionListener

使用init.gradle注册构建监听

上面咱们提到了不少接口，这些接口可使用gradle.addBuildListener方法或者gradle.addListener方法注册到整个构建过程。

• BuildListener

BuildListener在整个构建过程当中的特定点会回调特定的函数，如构建开始时会回调buildStarted，setting.gradle加载和评估完成后会回调settingsEvaluated，全部项目加载进来后会回调projectsLoaded，全部项目配置评估完成会回调projectsEvaluated，构建完成会回调buildFinished，具体例子以下：

//构建监听 gradle.addBuildListener(new BuildListener() { @Override void buildStarted(Gradle gradle) { //init.gradle被执行前,构建已经发生,且buildStarted已经被回调, // 所以后续加入的BuildListener都不会再调用buildStarted gradle.println("=========BuildListener:buildStarted=========") } @Override void settingsEvaluated(Settings settings) { //setting.gradle加载和评估配置阶段完成 gradle.println("=========BuildListener:settingsEvaluated=========") } @Override void projectsLoaded(Gradle gradle) { //项目加载完成 gradle.println("=========BuildListener:projectsLoaded=========") } @Override void projectsEvaluated(Gradle gradle) { //项目评估配置阶段结束 gradle.println("=========BuildListener:projectsEvaluated=========") } @Override void buildFinished(BuildResult result) { //构建完成 gradle.println("=========BuildListener:buildFinished=========") } })

 

可是buildStarted这个回调有点特殊，在构建开始后，init.gradle执行前，buildStarted方法就会被回调，所以在init.gradle加入的监听器buildStarted是不会被回调的，只有gradle内部注册的才会回调。这一细节能够从gradle的源码中看到。

import javafx.stage.Stage private BuildResult doBuild(final Stage upTo) { return buildOperationExecutor.run("Run build", new Factory<BuildResult>() { @Override public BuildResult create() { Throwable failure = null; try { //回调buildStarted，但此时init.gradle没有被执行，时机太早 buildListener.buildStarted(gradle); doBuildStages(upTo); } catch (Throwable t) { failure = exceptionAnalyser.transform(t); } BuildResult buildResult = new BuildResult(upTo.name(), gradle, failure); buildListener.buildFinished(buildResult); if (failure != null) { throw new ReportedException(failure); } return buildResult; } }); } private void doBuildStages(Stage upTo) { //执行init.gradle,此时buildStarted已经被回调，以后都不会再次回调，因此init.gradle中加入的监听器buildStarted都不会被回调 // Evaluate init scripts initScriptHandler.executeScripts(gradle); // Calculate projects settingsLoader.findAndLoadSettings(gradle); // Configure build buildOperationExecutor.run("Configure build", new Runnable() { @Override public void run() { buildConfigurer.configure(gradle); if (!gradle.getStartParameter().isConfigureOnDemand()) { buildListener.projectsEvaluated(gradle); } modelConfigurationListener.onConfigure(gradle); } }); if (upTo == Stage.Configure) { return; } // Populate task graph buildOperationExecutor.run("Calculate task graph", new Runnable() { @Override public void run() { buildConfigurationActionExecuter.select(gradle); if (gradle.getStartParameter().isConfigureOnDemand()) { buildListener.projectsEvaluated(gradle); } } }); // Execute build buildOperationExecutor.run("Run tasks", new Runnable() { @Override public void run() { buildExecuter.execute(gradle); } }); assert upTo == Stage.Build; }

ProjectEvaluationListener

ProjectEvaluationListener主要用于监听项目的配置评估阶段，配置评估开始前和完成后会回调。以下：

//配置评估监听 gradle.addProjectEvaluationListener(new ProjectEvaluationListener() { @Override void beforeEvaluate(Project project) { //项目配置评估前回调 gradle.println("=========ProjectEvaluationListener:beforeEvaluate ${project.getName()}=========") } @Override void afterEvaluate(Project project, ProjectState state) { //项目配置评估后回调 //若是失败,则failure不为null gradle.println("=========ProjectEvaluationListener:afterEvaluate ${state.executed} ${state.failure}=========") } }) 

 

TaskExecutionGraphListener

TaskExecutionGraphListener这个监听器能够在项目评估完成后得到须要构建的任务的全部依赖，好比下面的代码就能够得到我所执行的task的全部依赖。

gradle.addListener(new TaskExecutionGraphListener() { @Override void graphPopulated(TaskExecutionGraph graph) { gradle.println "=========from gradle.addListener graphPopulated=========" graph.allTasks.each { Task task -> gradle.println "=========TaskExecutionGraph:${task.getName()}=========" } } }

 

输出的内容以下：

./gradlew --I init.gradle assembleDebug
=========from gradle.addListener graphPopulated========= =========TaskExecutionGraph:preBuild========= =========TaskExecutionGraph:preDebugBuild========= =========TaskExecutionGraph:checkDebugManifest========= =========TaskExecutionGraph:preReleaseBuild========= =========TaskExecutionGraph:prepareComAndroidSupportAnimatedVectorDrawable2411Library========= =========TaskExecutionGraph:prepareComAndroidSupportAppcompatV72411Library========= =========TaskExecutionGraph:prepareComAndroidSupportSupportV42411Library========= =========TaskExecutionGraph:prepareComAndroidSupportSupportVectorDrawable2411Library========= =========TaskExecutionGraph:prepareDebugDependencies========= =========TaskExecutionGraph:compileDebugAidl========= =========TaskExecutionGraph:compileDebugRenderscript========= =========TaskExecutionGraph:generateDebugBuildConfig========= =========TaskExecutionGraph:mergeDebugShaders========= =========TaskExecutionGraph:compileDebugShaders========= =========TaskExecutionGraph:generateDebugAssets========= =========TaskExecutionGraph:mergeDebugAssets========= =========TaskExecutionGraph:generateDebugResValues========= =========TaskExecutionGraph:generateDebugResources========= =========TaskExecutionGraph:mergeDebugResources========= =========TaskExecutionGraph:processDebugManifest========= =========TaskExecutionGraph:processDebugResources========= =========TaskExecutionGraph:generateDebugSources========= =========TaskExecutionGraph:incrementalDebugJavaCompilationSafeguard========= =========TaskExecutionGraph:compileDebugJavaWithJavac========= =========TaskExecutionGraph:compileDebugNdk========= =========TaskExecutionGraph:compileDebugSources========= =========TaskExecutionGraph:prePackageMarkerForDebug========= =========TaskExecutionGraph:transformClassesWithDexForDebug========= =========TaskExecutionGraph:mergeDebugJniLibFolders========= =========TaskExecutionGraph:transformNative_libsWithMergeJniLibsForDebug========= =========TaskExecutionGraph:processDebugJavaRes========= =========TaskExecutionGraph:transformResourcesWithMergeJavaResForDebug========= =========TaskExecutionGraph:validateDebugSigning========= =========TaskExecutionGraph:packageDebug========= =========TaskExecutionGraph:zipalignDebug========= =========TaskExecutionGraph:assembleDebug========= 

 

TaskExecutionListener

TaskExecutionListener这个监听器能够用来监听构建过程当中全部task构建前和构建后。每个任务执行前会回调beforeExecute方法，执行完成后会回调afterExecute，执行的结果保存在入参TaskState中。

//等同gradle.taskGraph.addTaskExecutionListener
gradle.addListener(new TaskExecutionListener() {
    @Override void beforeExecute(Task task) { gradle.println "=========from gradle.addListener beforeExecute=========" gradle.println "=========TaskExecutionListener:beforeExecute:${task.getName()}=========" } @Override void afterExecute(Task task, TaskState state) { gradle.println "=========from gradle.addListener afterExecute=========" gradle.println "=========TaskExecutionListener:afterExecute:${task.getName()}=========" gradle.println "=========TaskState:[executed]${state.executed}=========" gradle.println "=========TaskState:[didWork]${state.didWork}=========" gradle.println "=========TaskState:[failure]${state.failure}=========" gradle.println "=========TaskState:[skipMessage]${state.skipMessage}=========" gradle.println "=========TaskState:[skipped]${state.skipped}=========" gradle.println "=========TaskState:[upToDate]${state.upToDate}=========" } })

 

DependencyResolutionListener

DependencyResolutionListener这个监听器能够用来监听构建过程当中依赖的关系，好比可使用这个监听器来检测release构建中是否包含snapshot包，若是包含则扔出异常中止构建。

//依赖监听
gradle.addListener(new DependencyResolutionListener() { @Override void beforeResolve(ResolvableDependencies resolvableDependencies) { gradle.println "DependencyResolutionListener:beforeResolve:=====${dependencies}=====" } @Override void afterResolve(ResolvableDependencies resolvableDependencies) { gradle.println "DependencyResolutionListener:afterResolve:=====${dependencies}=====" def projectPath = resolvableDependencies.path.toLowerCase() if (projectPath.contains("releasecompile")) { gradle.println "[DependencyResolutionListener] release detect:${resolvableDependencies.path}" resolvableDependencies.resolutionResult.allDependencies.each { dependency -> if (dependency instanceof org.gradle.api.internal.artifacts.result.DefaultUnresolvedDependencyResult) { gradle.println "DefaultUnresolvedDependencyResult reason: ${dependency.reason}" gradle.println "DefaultUnresolvedDependencyResult failure: ${dependency.failure}" } else if (dependency instanceof org.gradle.api.internal.artifacts.result.DefaultResolvedDependencyResult) { String selected = dependency.selected def from = dependency.from gradle.println "[DependencyResolutionListener] current dependency:${selected} which is from:${from}" if (selected != null && (selected.toLowerCase().contains("snapshot") || selected.toLowerCase().contains("beta"))) { String errorMessage = "[DependencyResolutionListener] [Error] ${selected} from ${from} contains a snapshot or beta version. you must fix it." gradle.println errorMessage throw new IllegalStateException(errorMessage) } } } } } })

 

StandardOutputListener

StandardOutputListener这个监听器能够获得控制台输出的log，除了输出到控制台后，能够对其进行重定向，好比输出到文件中去，以下：

//log输出的监听,能够将log输出到其余文件中去 gradle.addListener(new StandardOutputListener() { static File logFile = new File("log.txt"); static { if (logFile.exists()) { logFile.delete() } logFile.createNewFile() } @Override void onOutput(CharSequence output) { try { FileWriter writer = new FileWriter(logFile, true); writer.write(output.toString()); writer.close(); } catch (IOException e) { e.printStackTrace(); } } })

TaskActionListener

在一个Task中可能会有不少action，好比咱们经过doFirst和doLast加入的闭包都是action，TaskActionListener监听器就能够在这些actions执行前和执行完成后获得回调，以下：

//TaskAction监听器,Task.doFirst,Task.doLast等传入的闭包都是Action gradle.addListener(new TaskActionListener() { @Override void beforeActions(Task task) { //在全部action执行前回调 gradle.println "**********beforeActions:${task}**********" task.getActions().each { Action action -> gradle.println "**********${action}**********" } } @Override void afterActions(Task task) { //在全部action执行后回调 gradle.println "**********afterActions:${task}**********" task.getActions().each { Action action -> gradle.println "**********${action}**********" } } })

TestListener和TestOutputListener

这两个监听器主要是用于执行测试相关的task使用的，好比保存测试报告，可是实际测试中发现TestOutputListener中的方法怎么都不会回调，缘由未知，以下脚本：

//测试监听器
gradle.addListener(new TestListener() {
    @Override void beforeSuite(TestDescriptor suite) { gradle.println "beforeSuite:=====${suite.className} ${suite.name}=====" } @Override void afterSuite(TestDescriptor suite, TestResult result) { gradle.println "afterSuite:=====${suite.className} ${suite.name} ${result}=====" } @Override void beforeTest(TestDescriptor testDescriptor) { gradle.println "beforeTest:=====${testDescriptor.className} ${testDescriptor.name}=====" } @Override void afterTest(TestDescriptor testDescriptor, TestResult result) { gradle.println "afterTest:=====${testDescriptor.className} ${testDescriptor.name} ${result}=====" } }) //测试的输出监听,实际测试并无回调 gradle.addListener(new TestOutputListener() { @Override void onOutput(TestDescriptor testDescriptor, TestOutputEvent outputEvent) { gradle.println "onOutput:=====${testDescriptor} ${outputEvent}=====" gradle.println "message:${outputEvent.message}" gradle.println "destination:${outputEvent.destination}" } })

使用闭包

除了以上监听器以外，咱们还可使用闭包来监听构建的过程当中的事件回调，好比我只对构建完成这一事件感兴趣，则可使用

gradle.buildFinished { gradle.println "=========buildFinished=========" }

 

 

除了这一闭包，还可使用其余几个相关的闭包对感兴趣的事件进行注册，注册后对应的事件发生便会回调该闭包。

/** * 同上BuildListener和ProjectEvaluationListener */ gradle.buildStarted { gradle.println "=========buildStarted=========" } gradle.settingsEvaluated { gradle.println "=========settingsEvaluated=========" } gradle.projectsLoaded { gradle.println "=========projectsLoaded=========" } gradle.projectsEvaluated { gradle.println "=========projectsEvaluated=========" } gradle.buildFinished { gradle.println "=========buildFinished=========" } gradle.beforeProject { gradle.println "=========beforeProject=========" } gradle.afterProject { gradle.println "=========afterProject=========" }

 

其余

对于Task的依赖关系的得到，除了上面的注册TaskExecutionGraphListener监听器，还有其余的方式，即经过gradle.taskGraph来得到，具体的脚步以下：

//当前构建的任务依赖关系图
gradle.taskGraph.whenReady { TaskExecutionGraph taskGraph -> taskGraph.allTasks.each { Task task -> gradle.println "=========whenReady:taskGraph:${task.getName()}=========" } taskGraph.beforeTask { Task task -> gradle.println "=========whenReady:beforeTask:${task.getName()}=========" } taskGraph.afterTask { Task task -> gradle.println "=========whenReady:afterTask:${task.getName()}=========" } } //等同于上面的whenReady闭包中的内容 gradle.taskGraph.addTaskExecutionGraphListener(new TaskExecutionGraphListener() { @Override void graphPopulated(TaskExecutionGraph graph) { gradle.println "=========TaskExecutionGraphListener:graphPopulated=========" graph.allTasks.each { Task task -> gradle.println "=========TaskExecutionGraph:${task.getName()}=========" } } }) //等同于上面的whenReady闭包中的内容 gradle.taskGraph.addTaskExecutionListener(new TaskExecutionListener() { @Override void beforeExecute(Task task) { gradle.println "=========TaskExecutionListener:beforeExecute:${task.getName()}=========" } @Override void afterExecute(Task task, TaskState state) { gradle.println "=========TaskExecutionListener:afterExecute:${task.getName()}=========" gradle.println "=========TaskState:[executed]${state.executed}=========" gradle.println "=========TaskState:[didWork]${state.didWork}=========" gradle.println "=========TaskState:[failure]${state.failure}=========" gradle.println "=========TaskState:[skipMessage]${state.skipMessage}=========" gradle.println "=========TaskState:[skipped]${state.skipped}=========" gradle.println "=========TaskState:[upToDate]${state.upToDate}=========" } }) //得到root project gradle.taskGraph.addTaskExecutionGraphListener(new TaskExecutionGraphListener() { @Override void graphPopulated(TaskExecutionGraph graph) { gradle.println "========${gradle.rootProject}========" } })

 

监听器的应用（构建时间的监听）

对于监听器，咱们可使用它来计算各个task所执行的时间，而后输出控制台，以下:

class TimeListener implements TaskExecutionListener, BuildListener { private Clock clock private times = [] @Override void beforeExecute(Task task) { clock = new org.gradle.util.Clock() } @Override void afterExecute(Task task, TaskState taskState) { def ms = clock.timeInMs times.add([ms, task.path]) task.project.logger.warn "${task.path} spend ${ms}ms" } @Override void buildFinished(BuildResult result) { println "Task spend time:" for (time in times) { if (time[0] >= 50) { printf "%7sms %s\n", time } } } @Override void buildStarted(Gradle gradle) {} @Override void projectsEvaluated(Gradle gradle) {} @Override void projectsLoaded(Gradle gradle) {} @Override void settingsEvaluated(Settings settings) {} } gradle.addListener(new TimeListener())

 

监听器的补充 
其实关于监听器，并不是必定要在init.gradle中进行注册，咱们也能够彻底在咱们项目中注册监听，只不过在init.gradle中能够注册一些全局的公共功能的监听器，就像上面的构建时间的计算。

总结

Gradle和init.gradle相关的内容大概就这么多，总结起来，其有用的东西就是各类各样的监听器，可用于构建过程当中的hook，作一些本身的事情，还有就是能够进行全局的配置等。具体如何使用，可根据本身的需求进行定制。

 

转载自：https://blog.csdn.net/sbsujjbcy/article/details/52079413