继续上一篇 。
这篇从InProcessBuildActionExecuter.execute开始这一篇的内容。
在正式内容前，首先要讲个gradle构建的流程，这个也是接下来内容的流程。
Load->Configure->Build
大家可以思考下，这3步都主要做了什么事。
另外，从执行流程的事件通知来看，它还分成下面5个通知事件：
buildStarted //开始编译settingsEvaluated //settings处理完毕projectsLoaded //项目loadedprojectsEvaluated //项目处理完毕buildFinished //编译结束
一. InProcessBuildActionExecuter.execute
文件路径：subprojects\launcher\src\main\java\org\gradle\launcher\exec\InProcessBuildActionExecuter.java方法：public Object execute(BuildAction action, BuildRequestContext buildRequestContext, BuildActionParameters actionParameters, ServiceRegistry contextServices) { GradleLauncher gradleLauncher = gradleLauncherFactory.newInstance(action.getStartParameter(), buildRequestContext, contextServices); try { gradleLauncher.addStandardOutputListener(buildRequestContext.getOutputListener()); gradleLauncher.addStandardErrorListener(buildRequestContext.getErrorListener()); GradleBuildController buildController = new GradleBuildController(gradleLauncher); buildActionRunner.run(action, buildController); System.out.println("Sandy buildController.getResult(): " + buildController.getResult()); return buildController.getResult(); } finally { gradleLauncher.stop(); }}文件路径：subprojects\launcher\src\main\java\org\gradle\launcher\exec\InProcessBuildActionExecuter.java方法：public GradleInternal run() { try { System.out.println("Sandy GradleInternal run state: " + state); return (GradleInternal) getLauncher().run().getGradle(); } finally { state = State.Completed; }}文件路径：subprojects\launcher\src\main\java\org\gradle\launcher\exec\ChainingBuildActionRunner.java方法：@Overridepublic void run(BuildAction action, BuildController buildController) { System.out.println("Sandy ChainingBuildActionRunner run runners.size: " + runners.size()); for (BuildActionRunner runner : runners) { System.out.println("runner: " + runner); runner.run(action, buildController); if (buildController.hasResult()) { return; } } throw new UnsupportedOperationException(String.format("Don't know how to run a build action of type %s.", action.getClass().getSimpleName()));}文件路径：subprojects\launcher\src\main\java\org\gradle\tooling\internal\provider\ExecuteBuildActionRunner.java方法：public void run(BuildAction action, BuildController buildController) { System.out.println("ExecuteBuildActionRunner action: " + action + " buildController: " + buildController); if (action instanceof ExecuteBuildAction) { System.out.println("ExecuteBuildActionRunner run.."); buildController.run(); buildController.setResult(null); System.out.println("ExecuteBuildActionRunner result: " + "null"); }}文件路径：subprojects\launcher\src\main\java\org\gradle\launcher\exec\GradleBuildController.java方法:public GradleInternal run() { try { System.out.println("Sandy GradleInternal run state: " + state); return (GradleInternal) getLauncher().run().getGradle(); } finally { state = State.Completed; }} 上面的步骤比较清晰明了，需要注意的是ChainingBuildActionRunner和ExecuteBuildActionRunner，其实他们都是同一个接口BuildActionRunner，所以这里又是喜闻乐见的装饰者模式。
public class ChainingBuildActionRunner implements BuildActionRunner { private final List runners; public ChainingBuildActionRunner(List runners) { this.runners = runners; }}public class ExecuteBuildActionRunner implements BuildActionRunner {} 最后来到ExecuteBuildActionRunner.run方法，它会调用GradleBuildController.run()，顾名思义，它是GradleBuild的控制器，所以马上就要接触到Gradle build步骤了；接下来会调用DefaultGradleLauncher.run()方法。
二. DefaultGradleLauncher
@Overridepublic BuildResult run() { return doBuild(Stage.Build);}private BuildResult doBuild(final Stage upTo) { return buildOperationExecutor.run("Run build", new Factory () { @Override public BuildResult create() { Throwable failure = null; try { System.out.println("buildListener: " + buildListener.getClass() + " gradle: " + gradle.getClass()); 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; } });} 首先来看buildListener.buildStarted(gradle); 这行代码的作用是通知gradle构建已经开始，那既然是通知，接收者是谁呢？
看buildListener赋值的地方：
文件路径：subprojects\core\src\main\java\org\gradle\initialization\DefaultGradleLauncher.java
方法
public DefaultGradleLauncher(GradleInternal gradle, InitScriptHandler initScriptHandler, SettingsLoader settingsLoader, BuildConfigurer buildConfigurer, ExceptionAnalyser exceptionAnalyser, LoggingManagerInternal loggingManager, BuildListener buildListener, ModelConfigurationListener modelConfigurationListener, BuildCompletionListener buildCompletionListener, BuildOperationExecutor operationExecutor, BuildConfigurationActionExecuter buildConfigurationActionExecuter, BuildExecuter buildExecuter, BuildScopeServices buildServices) { ... this.buildListener = buildListener; ...} 继续看调动的地方
文件路径：
subprojects\core\src\main\java\org\gradle\initialization\DefaultGradleLauncherFactory.java
方法：
return new DefaultGradleLauncher( ... gradle.getBuildListenerBroadcaster(), ... );
//文件路径：
subprojects\core\src\main\java\org\gradle\invocation\DefaultGradle.java
public BuildListener getBuildListenerBroadcaster() { return buildListenerBroadcast.getSource();} public DefaultGradle(Gradle parent, StartParameter startParameter, ServiceRegistryFactory parentRegistry) { ... buildListenerBroadcast = getListenerManager().createAnonymousBroadcaster(BuildListener.class); projectEvaluationListenerBroadcast = getListenerManager().createAnonymousBroadcaster(ProjectEvaluationListener.class); buildListenerBroadcast.add(new BuildAdapter() { @Override public void buildStarted(Gradle gradle) { super.buildStarted(gradle); Exception ex = new Exception("Sandy buildStarted"); ex.printStackTrace(); System.out.println("buildListenerBroadcast sandy buildStarted"); } @Override public void settingsEvaluated(Settings settings) { super.settingsEvaluated(settings); Exception ex = new Exception("Sandy settingsEvaluated"); ex.printStackTrace(); System.out.println("buildListenerBroadcast sandy settingsEvaluated"); } @Override public void projectsEvaluated(Gradle gradle) { super.projectsEvaluated(gradle); System.out.println("buildListenerBroadcast sandy projectsEvaluated"); } @Override public void buildFinished(BuildResult result) { super.buildFinished(result); System.out.println("buildListenerBroadcast sandy buildFinished"); } @Override public void projectsLoaded(Gradle gradle) { System.out.println("buildListenerBroadcast sandy projectsLoaded"); rootProjectActions.execute(rootProject); rootProjectActions = null; } }); } 嗯，也就是接受者是在DefaultGradle里面，也就是说通知gradle build已经开始，接下来看doBuildStages(Stage.Build)方法，这个方法很重要，gradle build的主要流程都在这里面。
private void doBuildStages(Stage upTo) { if (stage == Stage.Build) { throw new IllegalStateException("Cannot build with GradleLauncher multiple times"); } if (stage == null) { // Evaluate init scripts initScriptHandler.executeScripts(gradle); // Build `buildSrc`, load settings.gradle, and construct composite (if appropriate) settings = settingsLoader.findAndLoadSettings(gradle); stage = Stage.Load; } if (upTo == Stage.Load) { return; } if (stage == Stage.Load) { // 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); } }); stage = Stage.Configure; } if (upTo == Stage.Configure) { return; } // After this point, the GradleLauncher cannot be reused stage = Stage.Build; // 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); } }); } 还记得最开始说过的gradle构建分成3个步骤吗？Load-> Configure->Build
那这个方法doBuildStages可以很清楚的看到这个流程，大家看下上面的代码即可明白，那接下来我们一步步分析这个过程。
三. Load.executeScripts 初始化脚本
if (stage == null) { // Evaluate init scripts initScriptHandler.executeScripts(gradle); // Build `buildSrc`, load settings.gradle, and construct composite (if appropriate) settings = settingsLoader.findAndLoadSettings(gradle); stage = Stage.Load;} 1. 首先来看第一行
initScriptHandler.executeScripts(gradle);
// Evaluate init scripts 看解释是统计初始化脚本，那具体是干什么呢？
文件路径：
subprojects\core\src\main\java\org\gradle\initialization\InitScriptHandler.java
/** * Finds and executes all init scripts for a given build. */public class InitScriptHandler { ... public void executeScripts(final GradleInternal gradle) { System.out.println("executeScripts"); final List initScripts = gradle.getStartParameter().getAllInitScripts(); if (initScripts.isEmpty()) { return; } BuildOperationDetails operationDetails = BuildOperationDetails.displayName("Run init scripts").progressDisplayName("init scripts").build(); buildOperationExecutor.run(operationDetails, new Runnable() { @Override public void run() { for (File script : initScripts) { System.out.println("InitScriptHandler run processor" + processor); processor.process(new UriScriptSource("initialization script", script), gradle); } } }); }} 从类InitScriptHandler的注释就知道，这个类的作用是找到并且执行初始化脚本，那我们接下来看看：
a. 它说的初始化脚本指的是什么？
b. 怎么执行初始化脚本的？
2. 首先来看getAllInitScripts是在干什么：
subprojects\core\src\main\java\org\gradle\StartParameter.java
public ListgetAllInitScripts() { CompositeInitScriptFinder initScriptFinder = new CompositeInitScriptFinder( new UserHomeInitScriptFinder(getGradleUserHomeDir()), new DistributionInitScriptFinder(gradleHomeDir) ); List scripts = new ArrayList (getInitScripts()); initScriptFinder.findScripts(scripts); return Collections.unmodifiableList(scripts); }
subprojects\core\src\main\java\org\gradle\initialization\UserHomeInitScriptFinder.java
public void findScripts(Collectionscripts) { File userInitScript = new File(userHomeDir, "init.gradle"); if (userInitScript.isFile()) { scripts.add(userInitScript); } findScriptsInDir(new File(userHomeDir, "init.d"), scripts); }
subprojects\core\src\main\java\org\gradle\initialization\DistributionInitScriptFinder.java
public void findScripts(Collectionscripts) { if (gradleHome == null) { return; } findScriptsInDir(new File(gradleHome, "init.d"), scripts); }
3个作用:
a. 尝试找到环境变量'GRADLE_USER_HOME'目录下的init.gradle文件，并加入列表。
如果没有配置环境变量'GRADLE_USER_HOME'，那么目录就是'C:\Users\xxx(你的用户名)\.gradle'
b. 找到环境变量'GRADLE_USER_HOME'下面init.d目录下的 *.gradle配置文件，并加入列表。
c. 找到gradle home目录下init.d目录的 *.gradle配置文件，并加入列表。
我的gradle_user_home和gradle_home分别是：
gradleUserHomeDir=D:\gradle_jar_cachegradleHome=E:\work_space\gradle-source-from-csdn\gradle-3.1\build\distributions\gradle-3.1-snapshot-1
其实如果大家去看下gradle home目录的init.d目录，你会发现里面有个readme.txt文件，里面有这样的描述：
You can add .gradle init scripts to this directory. Each one is executed at the start of the build.
那我们的Gradle 源代码流程分析也验证了这句话。
3. 然后来看看processor.process在干什么
for (File script : initScripts) { processor.process(new UriScriptSource("initialization script", script), gradle);} 首先initScripts是指上面我们统计3个目录下得到的脚本文件集合，那这里就是挨个执行它们。
那UriScriptSource是用来解析传入的script文件，把它的内容读出来。
那继续看process方法
文件路径：
subprojects\core\src\main\java\org\gradle\configuration\DefaultInitScriptProcessor.java
/** * Processes (and runs) an init script for a specified build. Handles defining * the classpath based on the initscript {} configuration closure. */public class DefaultInitScriptProcessor implements InitScriptProcessor { ... public void process(final ScriptSource initScript, GradleInternal gradle) { .... configurer.apply(gradle); }} 文件路径：
subprojects\core\src\main\java\org\gradle\configuration\DefaultScriptPluginFactory.java
public void apply(final Object target) { System.out.println("ScriptPluginImpl apply 1"); ... // Pass 1, extract plugin requests and plugin repositories and execute buildscript {}, ignoring (i.e. not even compiling) anything else Class scriptType = initialPassScriptTarget.getScriptClass(); InitialPassStatementTransformer initialPassStatementTransformer = new InitialPassStatementTransformer(scriptSource, initialPassScriptTarget, documentationRegistry); SubsetScriptTransformer initialTransformer = new SubsetScriptTransformer(initialPassStatementTransformer); String id = INTERNER.intern("cp_" + initialPassScriptTarget.getId()); CompileOperation initialOperation = new FactoryBackedCompileOperation (id, initialTransformer, initialPassStatementTransformer, pluginRequestsSerializer); ScriptRunner initialRunner = compiler.compile(scriptType, initialOperation, baseScope.getExportClassLoader(), Actions.doNothing()); initialRunner.run(target, services); PluginRequests pluginRequests = initialRunner.getData(); PluginManagerInternal pluginManager = initialPassScriptTarget.getPluginManager(); System.out.println("ScriptPluginImpl apply is empty: " + pluginRequests.isEmpty()); pluginRequestApplicator.applyPlugins(pluginRequests, scriptHandler, pluginManager, targetScope); System.out.println("ScriptPluginImpl apply 4"); // Pass 2, compile everything except buildscript {}, pluginRepositories{}, and plugin requests, then run final ScriptTarget scriptTarget = secondPassTarget(target); scriptType = scriptTarget.getScriptClass(); BuildScriptTransformer buildScriptTransformer = new BuildScriptTransformer(scriptSource, scriptTarget); String operationId = scriptTarget.getId(); CompileOperation operation = new FactoryBackedCompileOperation (operationId, buildScriptTransformer, buildScriptTransformer, buildScriptDataSerializer); final ScriptRunner runner = compiler.compile(scriptType, operation, targetScope.getLocalClassLoader(), ClosureCreationInterceptingVerifier.INSTANCE); if (scriptTarget.getSupportsMethodInheritance() && runner.getHasMethods()) { System.out.println("ScriptPluginImpl apply 5"); scriptTarget.attachScript(runner.getScript()); } System.out.println("ScriptPluginImpl apply 6"); if (!runner.getRunDoesSomething()) { System.out.println("ScriptPluginImpl apply 7"); return; } Runnable buildScriptRunner = new Runnable() { public void run() { System.out.println("ScriptPluginImpl apply 8"); runner.run(target, services); } }; System.out.println("ScriptPluginImpl apply 9"); boolean hasImperativeStatements = runner.getData().getHasImperativeStatements(); scriptTarget.addConfiguration(buildScriptRunner, !hasImperativeStatements); } 执行流程:
a. 在DefaultScriptPluginFactory的apply里面主要有两步 pass1/ pass2
在pass1的时候，处理的文件是
'D:\gradle_jar_cache\caches\3.1-snapshot-1\scripts-remapped\settings_brbxf8awmquo5r6nxrgcmg7fq\iaw3k0vmpedkxsp2gv9xvnom\cp_settingsd7eae713beda1bd9e69f8461da734880\metadata\metadata.bin'
b. 在pass2的时候，处理初始化脚本，如果脚本文件里面有配置，则会到走到'ScriptPluginImpl apply 8' 加载这个脚本的属性；
如果脚本里面有配置，只是一个空文件，则从'ScriptPluginImpl apply 7'返回。
总结下这个步骤的内容：
a. 加载gradle_user_home下面init.gradle和init.d/目录下 *.gradle以及gradle home 目录下的init.d/目录下的 *.gradle文件
b. 如果有这些文件，而且内容不为空，那么将会加载它们配置的属性。
比较重要也很令人费解是这行代码：
scriptCompilerFactory.createCompiler(scriptSource);
这行代码粗看没有什么，但是仔细分析后其实大有乾坤！它是在为下一行
initialRunner.run(target, services);
生成可以加载的Java类，最终调用DefaultScriptCompilationHandler.compileToDir来生成类。 生成的类路径如下：
D:\gradle_jar_cache\caches\3.1-snapshot-1\scripts\df5frxe005h8vnbjcuzkr2g0s\cp_settings\cp_settingsd7eae713beda1bd9e69f8461da734880执行堆栈如下：
java.lang.Exception: Sandy compile to dir at org.gradle.groovy.scripts.internal.DefaultScriptCompilationHandler.compileToDir(DefaultScriptCompilationHandler.java:97) at org.gradle.groovy.scripts.internal.FileCacheBackedScriptClassCompiler$CompileToCrossBuildCacheAction.execute(FileCacheBackedScriptClassCompiler.java:160) at org.gradle.groovy.scripts.internal.FileCacheBackedScriptClassCompiler$CompileToCrossBuildCacheAction.execute(FileCacheBackedScriptClassCompiler.java:141) at org.gradle.groovy.scripts.internal.FileCacheBackedScriptClassCompiler$Progre***eportingInitializer.execute(FileCacheBackedScriptClassCompiler.java:185) at org.gradle.groovy.scripts.internal.FileCacheBackedScriptClassCompiler$Progre***eportingInitializer.execute(FileCacheBackedScriptClassCompiler.java:164) at org.gradle.cache.internal.DefaultPersistentDirectoryCache$Initializer.initialize(DefaultPersistentDirectoryCache.java:100) at org.gradle.cache.internal.DefaultCacheAccess$2.run(DefaultCacheAccess.java:116) at org.gradle.cache.internal.DefaultFileLockManager$DefaultFileLock.doWriteAction(DefaultFileLockManager.java:179) at org.gradle.cache.internal.DefaultFileLockManager$DefaultFileLock.writeFile(DefaultFileLockManager.java:169) at org.gradle.cache.internal.DefaultCacheAccess.open(DefaultCacheAccess.java:113) at org.gradle.cache.internal.DefaultPersistentDirectoryStore.open(DefaultPersistentDirectoryStore.java:47) at org.gradle.cache.internal.DefaultPersistentDirectoryStore.open(DefaultPersistentDirectoryStore.java:28) at org.gradle.cache.internal.DefaultCacheFactory.doOpen(DefaultCacheFactory.java:83) at org.gradle.cache.internal.DefaultCacheFactory.open(DefaultCacheFactory.java:51) at org.gradle.cache.internal.DefaultCacheRepository$PersistentCacheBuilder.doOpen(DefaultCacheRepository.java:147) at org.gradle.cache.internal.DefaultCacheRepository$AbstractCacheBuilder.open(DefaultCacheRepository.java:121) at org.gradle.groovy.scripts.internal.FileCacheBackedScriptClassCompiler$RemapBuildScriptsAction.execute(FileCacheBackedScriptClassCompiler.java:365) at org.gradle.groovy.scripts.internal.FileCacheBackedScriptClassCompiler$RemapBuildScriptsAction.execute(FileCacheBackedScriptClassCompiler.java:333) at org.gradle.groovy.scripts.internal.FileCacheBackedScriptClassCompiler$Progre***eportingInitializer.execute(FileCacheBackedScriptClassCompiler.java:185) at org.gradle.groovy.scripts.internal.FileCacheBackedScriptClassCompiler$Progre***eportingInitializer.execute(FileCacheBackedScriptClassCompiler.java:164) at org.gradle.cache.internal.DefaultPersistentDirectoryCache$Initializer.initialize(DefaultPersistentDirectoryCache.java:100) at org.gradle.cache.internal.DefaultCacheAccess$2.run(DefaultCacheAccess.java:116) at org.gradle.cache.internal.DefaultFileLockManager$DefaultFileLock.doWriteAction(DefaultFileLockManager.java:179) at org.gradle.cache.internal.DefaultFileLockManager$DefaultFileLock.writeFile(DefaultFileLockManager.java:169) at org.gradle.cache.internal.DefaultCacheAccess.open(DefaultCacheAccess.java:113) at org.gradle.cache.internal.DefaultPersistentDirectoryStore.open(DefaultPersistentDirectoryStore.java:47) at org.gradle.cache.internal.DefaultPersistentDirectoryStore.open(DefaultPersistentDirectoryStore.java:28) at org.gradle.cache.internal.DefaultCacheFactory.doOpen(DefaultCacheFactory.java:83) at org.gradle.cache.internal.DefaultCacheFactory.open(DefaultCacheFactory.java:51) at org.gradle.cache.internal.DefaultCacheRepository$PersistentCacheBuilder.doOpen(DefaultCacheRepository.java:147) at org.gradle.cache.internal.DefaultCacheRepository$AbstractCacheBuilder.open(DefaultCacheRepository.java:121) at org.gradle.groovy.scripts.internal.FileCacheBackedScriptClassCompiler.compile(FileCacheBackedScriptClassCompiler.java:111) at org.gradle.groovy.scripts.internal.CrossBuildInMemoryCachingScriptClassCache.getOrCompile(CrossBuildInMemoryCachingScriptClassCache.java:46) at org.gradle.groovy.scripts.internal.BuildScopeInMemoryCachingScriptClassCompiler.compile(BuildScopeInMemoryCachingScriptClassCompiler.java:48) at org.gradle.groovy.scripts.DefaultScriptCompilerFactory$ScriptCompilerImpl.compile(DefaultScriptCompilerFactory.java:50) at org.gradle.configuration.DefaultScriptPluginFactory$ScriptPluginImpl.apply(DefaultScriptPluginFactory.java:154) at org.gradle.configuration.project.BuildScriptProcessor.execute(BuildScriptProcessor.java:40) at org.gradle.configuration.project.BuildScriptProcessor.execute(BuildScriptProcessor.java:25) at org.gradle.configuration.project.ConfigureActionsProjectEvaluator.evaluate(ConfigureActionsProjectEvaluator.java:34) at org.gradle.configuration.project.LifecycleProjectEvaluator.evaluate(LifecycleProjectEvaluator.java:55) at org.gradle.api.internal.project.DefaultProject.evaluate(DefaultProject.java:573) at org.gradle.api.internal.project.DefaultProject.evaluate(DefaultProject.java:125) at org.gradle.execution.TaskPathProjectEvaluator.configureHierarchy(TaskPathProjectEvaluator.java:42) at org.gradle.configuration.DefaultBuildConfigurer.configure(DefaultBuildConfigurer.java:38) at org.gradle.initialization.DefaultGradleLauncher$2.run(DefaultGradleLauncher.java:154) at org.gradle.internal.Factories$1.create(Factories.java:22) at org.gradle.internal.progress.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:91) at org.gradle.internal.progress.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:53) at org.gradle.initialization.DefaultGradleLauncher.doBuildStages(DefaultGradleLauncher.java:151) at org.gradle.initialization.DefaultGradleLauncher.access$200(DefaultGradleLauncher.java:33) at org.gradle.initialization.DefaultGradleLauncher$1.create(DefaultGradleLauncher.java:114) at org.gradle.initialization.DefaultGradleLauncher$1.create(DefaultGradleLauncher.java:106) at org.gradle.internal.progress.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:91) at org.gradle.internal.progress.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:63) at org.gradle.initialization.DefaultGradleLauncher.doBuild(DefaultGradleLauncher.java:106) at org.gradle.initialization.DefaultGradleLauncher.run(DefaultGradleLauncher.java:92) at org.gradle.launcher.exec.GradleBuildController.run(GradleBuildController.java:67) at org.gradle.tooling.internal.provider.ExecuteBuildActionRunner.run(ExecuteBuildActionRunner.java:31) at org.gradle.launcher.exec.ChainingBuildActionRunner.run(ChainingBuildActionRunner.java:43) at org.gradle.launcher.exec.InProcessBuildActionExecuter.execute(InProcessBuildActionExecuter.java:42) at org.gradle.launcher.exec.InProcessBuildActionExecuter.execute(InProcessBuildActionExecuter.java:26) at org.gradle.tooling.internal.provider.ContinuousBuildActionExecuter.execute(ContinuousBuildActionExecuter.java:79) at org.gradle.tooling.internal.provider.ContinuousBuildActionExecuter.execute(ContinuousBuildActionExecuter.java:51) at org.gradle.launcher.cli.RunBuildAction.run(RunBuildAction.java:54) at org.gradle.internal.Actions$RunnableActionAdapter.execute(Actions.java:173) at org.gradle.launcher.cli.CommandLineActionFactory$ParseAndBuildAction.execute(CommandLineActionFactory.java:250) at org.gradle.launcher.cli.CommandLineActionFactory$ParseAndBuildAction.execute(CommandLineActionFactory.java:217) at org.gradle.launcher.cli.JavaRuntimeValidationAction.execute(JavaRuntimeValidationAction.java:33) at org.gradle.launcher.cli.JavaRuntimeValidationAction.execute(JavaRuntimeValidationAction.java:24) at org.gradle.launcher.cli.ExceptionReportingAction.execute(ExceptionReportingAction.java:33) at org.gradle.launcher.cli.ExceptionReportingAction.execute(ExceptionReportingAction.java:22) at org.gradle.launcher.cli.CommandLineActionFactory$WithLogging.execute(CommandLineActionFactory.java:210) at org.gradle.launcher.cli.CommandLineActionFactory$WithLogging.execute(CommandLineActionFactory.java:174) at org.gradle.launcher.Main.doAction(Main.java:33) at org.gradle.launcher.bootstrap.EntryPoint.run(EntryPoint.java:45) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:483) at org.gradle.launcher.bootstrap.ProcessBootstrap.runNoExit(ProcessBootstrap.java:60) at org.gradle.launcher.bootstrap.ProcessBootstrap.run(ProcessBootstrap.java:37) at org.gradle.launcher.GradleMain.main(GradleMain.java:24)
接下来，继续往下面看Load步骤的第二个步骤findAndLoadSettings.
// Build `buildSrc`, load settings.gradle, and construct composite (if appropriate)settings = settingsLoader.findAndLoadSettings(gradle);
四. Load.findAndLoadSettings
settings = settingsLoader.findAndLoadSettings(gradle);
首先settingsLoader使用了装饰者模式，从外到内包装顺序是：
public class NotifyingSettingsLoader implements SettingsLoader { private final SettingsLoader settingsLoader; ... @Override public SettingsInternal findAndLoadSettings(GradleInternal gradle) { SettingsInternal settings = settingsLoader.findAndLoadSettings(gradle); gradle.getBuildListenerBroadcaster().settingsEvaluated(settings); buildLoader.load(settings.getRootProject(), settings.getDefaultProject(), gradle, settings.getRootClassLoaderScope()); gradle.getBuildListenerBroadcaster().projectsLoaded(gradle); return settings; }}public class CompositeBuildSettingsLoader implements SettingsLoader { private final SettingsLoader delegate; ... @Override public SettingsInternal findAndLoadSettings(GradleInternal gradle) { SettingsInternal settings = delegate.findAndLoadSettings(gradle); ... }}/** * Handles locating and processing setting.gradle files. Also deals with the buildSrc module, since that modules is * found after settings is located, but needs to be built before settings is processed. */public class DefaultSettingsLoader implements SettingsLoader { ... @Override public SettingsInternal findAndLoadSettings(GradleInternal gradle) { ... SettingsInternal settings = findSettingsAndLoadIfAppropriate(gradle, startParameter); ... ProjectSpec spec = ProjectSpecs.forStartParameter(startParameter, settings); System.out.println(" spec: " + spec); if (spec.containsProject(settings.getProjectRegistry())) { System.out.println("spec.containsProject"); setDefaultProject(spec, settings); return settings; } // Try again with empty settings StartParameter noSearchParameter = startParameter.newInstance(); noSearchParameter.useEmptySettings(); settings = findSettingsAndLoadIfAppropriate(gradle, noSearchParameter); // Set explicit build file, if required if (noSearchParameter.getBuildFile() != null) { ProjectDescriptor rootProject = settings.getRootProject(); rootProject.setBuildFileName(noSearchParameter.getBuildFile().getName()); } setDefaultProject(spec, settings); return settings;} NotifyingSettingsLoader首先会根据装饰者模式逐个的调用进去，所以DefaultSettingsLoader.findAndLoadSettings方法，然后在回头看NotifyingSettingsLoader.findAndLoadSettings的其他代码。
DefaultSettingsLoader根据注释，它是要处理项目目录下的setting.gradle文件，同时处理buildSrc模块，这个好像一般项目没有。
所以，可以先看DefaultSettingsLoader.findAndLoadSettings方法。
1. DefaultSettingsLoader
文件路径：
subprojects\core\src\main\java\org\gradle\initialization\DefaultSettingsLoader.java
@Overridepublic SettingsInternal findAndLoadSettings(GradleInternal gradle) { StartParameter startParameter = gradle.getStartParameter(); System.out.println("DefaultSettingsLoader.findAndLoadSettings startParameter: " + startParameter + " gradle: " + gradle); SettingsInternal settings = findSettingsAndLoadIfAppropriate(gradle, startParameter); System.out.println(" settings: " + settings); ProjectSpec spec = ProjectSpecs.forStartParameter(startParameter, settings); System.out.println(" spec: " + spec); if (spec.containsProject(settings.getProjectRegistry())) { System.out.println("spec.containsProject"); setDefaultProject(spec, settings); return settings; } // Try again with empty settings StartParameter noSearchParameter = startParameter.newInstance(); noSearchParameter.useEmptySettings(); settings = findSettingsAndLoadIfAppropriate(gradle, noSearchParameter); // Set explicit build file, if required if (noSearchParameter.getBuildFile() != null) { ProjectDescriptor rootProject = settings.getRootProject(); rootProject.setBuildFileName(noSearchParameter.getBuildFile().getName()); } setDefaultProject(spec, settings); return settings;} private SettingsInternal findSettingsAndLoadIfAppropriate(GradleInternal gradle, ... return settingsProcessor.process(gradle, settingsLocation, buildSourceClassLoader, startParameter);} 2. 首先看findSettingsAndLoadIfAppropriate 这个方法。看名字应该是寻找Settings并尝试加载它。它调用的是settingsProcessor.process 这个settingsProcessor又使用了装饰者模式，共有3个类。public class NotifyingSettingsProcessor implements SettingsProcessor {}public class PropertiesLoadingSettingsProcessor implements SettingsProcessor { public SettingsInternal process(GradleInternal gradle, SettingsLocation settingsLocation, ClassLoaderScope baseClassLoaderScope, StartParameter startParameter) { System.out.println("PropertiesLoadingSettingsProcessor run"); propertiesLoader.loadProperties(settingsLocation.getSettingsDir()); return processor.process(gradle, settingsLocation, baseClassLoaderScope, startParameter); }}public class ScriptEvaluatingSettingsProcessor implements SettingsProcessor { public SettingsInternal process(GradleInternal gradle, SettingsLocation settingsLocation, ClassLoaderScope baseClassLoaderScope, StartParameter startParameter) { System.out.println("Script Process process"); Clock settingsProcessingClock = new Clock(); Map properties = propertiesLoader.mergeProperties(Collections. emptyMap()); SettingsInternal settings = settingsFactory.createSettings(gradle, settingsLocation.getSettingsDir(), settingsLocation.getSettingsScriptSource(), properties, startParameter, baseClassLoaderScope); applySettingsScript(settingsLocation, settings); LOGGER.debug("Timing: Processing settings took: {}", settingsProcessingClock.getTime()); return settings; }} 真的，gradle源代码使用了很多装饰者模式。
3. 首先看看PropertiesLoadingSettingsProcessor.process方法
文件路径：subprojects\core\src\main\java\org\gradle\initialization\PropertiesLoadingSettingsProcessor.java
public class PropertiesLoadingSettingsProcessor implements SettingsProcessor { ... public SettingsInternal process(GradleInternal gradle, SettingsLocation settingsLocation, ClassLoaderScope baseClassLoaderScope, StartParameter startParameter) { System.out.println("PropertiesLoadingSettingsProcessor run"); propertiesLoader.loadProperties(settingsLocation.getSettingsDir()); return processor.process(gradle, settingsLocation, baseClassLoaderScope, startParameter); }} 文件路径：
subprojects\core\src\main\java\org\gradle\initialization\DefaultGradlePropertiesLoader.java
public static final String SYSTEM_PROP_PREFIX = "systemProp";String ENV_PROJECT_PROPERTIES_PREFIX = "ORG_GRADLE_PROJECT_";String SYSTEM_PROJECT_PROPERTIES_PREFIX = "org.gradle.project.";public void loadProperties(File settingsDir) { loadProperties(settingsDir, startParameter, getAllSystemProperties(), getAllEnvProperties()); } void loadProperties(File settingsDir, StartParameter startParameter, Map systemProperties, Map envProperties) { defaultProperties.clear(); overrideProperties.clear(); addGradleProperties(defaultProperties, new File(settingsDir, Project.GRADLE_PROPERTIES)); addGradleProperties(overrideProperties, new File(startParameter.getGradleUserHomeDir(), Project.GRADLE_PROPERTIES)); setSystemProperties(startParameter.getSystemPropertiesArgs()); overrideProperties.putAll(getEnvProjectProperties(envProperties)); overrideProperties.putAll(getSystemProjectProperties(systemProperties)); for (String key : systemProperties.keySet()) { System.out.println("system properties, key: " + key + " value: " + systemProperties.get(key)); } for (String key : envProperties.keySet()) { System.out.println("env properties, key: " + key + " value: " + envProperties.get(key)); } overrideProperties.putAll(startParameter.getProjectProperties());} private void setSystemProperties(Map properties) { addSystemPropertiesFromGradleProperties(defaultProperties); addSystemPropertiesFromGradleProperties(overrideProperties); System.getProperties().putAll(properties);}private void addSystemPropertiesFromGradleProperties(Map properties) { for (String key : properties.keySet()) { if (key.startsWith(Project.SYSTEM_PROP_PREFIX + '.')) { System.setProperty(key.substring((Project.SYSTEM_PROP_PREFIX + '.').length()), properties.get(key)); } }} 在loadProperties方法里面，它首先调用addGradleProperties方法分别把
a. 项目路径下面的gradle.properties
b. gradle_user_home路径下面的gradle.properties
两个文件分别读取到defaultProperties和overrideProperties两个map中。
比如，像这种属性：
org.gradle.jvmargs=-Xmx1536m# When configured, Gradle will run in incubating parallel mode.# This option should only be used with decoupled projects. More details, visit# http://www.gradle.org/docs/current/userguide/multi_project_builds.html#sec:decoupled_projects# org.gradle.parallel=true
然后调用addSystemProperties方法把项目目录和gradle_user_home目录gradle.properties两个文件里面'systemProp'开头的属性设置到系统属性里面；同时把读取到的系统属性也设置进去。
再然后调用overrideProperties.putAll把环境变量中'ORG_GRADLE_PROJECT_'和系统属性中'org.gradle.project.'开头的变量，存放到overrideProperties map集合中。
最后，把projectProperties属性加入到overrideProperties map集合中。
4. 继续看ScriptEvaluatingSettingsProcessor.process
因为是装饰者模式，所以在调用完PropertiesLoadingSettingsProcessor.process之后，就会继续调用它里面包装的ScriptEvaluatingSettingsProcessor.process，代码如下：
文件路径：subprojects\core\src\main\java\org\gradle\initialization\ScriptEvaluatingSettingsProcessor.java
public class ScriptEvaluatingSettingsProcessor implements SettingsProcessor { ... public SettingsInternal process(GradleInternal gradle, SettingsLocation settingsLocation, ClassLoaderScope baseClassLoaderScope, StartParameter startParameter) { ... Map properties = propertiesLoader.mergeProperties(Collections. emptyMap()); SettingsInternal settings = settingsFactory.createSettings(gradle, settingsLocation.getSettingsDir(), settingsLocation.getSettingsScriptSource(), properties, startParameter, baseClassLoaderScope); applySettingsScript(settingsLocation, settings); ... } ... //文件路径：subprojects\core\src\main\java\org\gradle\initialization\DefaultGradlePropertiesLoader.java public Map mergeProperties(Map properties) { Map result = new HashMap (); result.putAll(defaultProperties); result.putAll(properties); result.putAll(overrideProperties); return result; } private void applySettingsScript(SettingsLocation settingsLocation, final SettingsInternal settings) { ScriptSource settingsScriptSource = settingsLocation.getSettingsScriptSource(); ClassLoaderScope settingsClassLoaderScope = settings.getClassLoaderScope(); ScriptHandler scriptHandler = scriptHandlerFactory.create(settingsScriptSource, settingsClassLoaderScope); ScriptPlugin configurer = configurerFactory.create(settingsScriptSource, scriptHandler, settingsClassLoaderScope, settings.getRootClassLoaderScope(), true); System.out.println("applySettingsScript configurer: " + configurer); configurer.apply(settings); }} 首先呢，把上一步加载好的属性都merge在一起，放到properties里面。
然后调用configurer.apply(settings)设置项目目录下settings.gradle文件属性
那DefaultSettingsLoader.findAndLoadSettings就基本结束了，回过头去看看NotifyingSettingsLoader.findAndLoadSettings的剩余部分代码。
5. 继续看NotifyingSettingsLoader.
public class NotifyingSettingsLoader implements SettingsLoader { ... @Override public SettingsInternal findAndLoadSettings(GradleInternal gradle) { SettingsInternal settings = settingsLoader.findAndLoadSettings(gradle); ... gradle.getBuildListenerBroadcaster().settingsEvaluated(settings); buildLoader.load(settings.getRootProject(), settings.getDefaultProject(), gradle, settings.getRootClassLoaderScope()); gradle.getBuildListenerBroadcaster().projectsLoaded(gradle); return settings; }} 首先发送一个事件通知settingsEvaulated，就是settings配置文件处理完毕。
然后调用buildLoader.load(xxx)
buildLoader又是使用了一个装饰者模式！从外到内包装如下：
public class ProjectPropertySettingBuildLoader implements BuildLoader { ... public void load(ProjectDescriptor rootProjectDescriptor, ProjectDescriptor defaultProject, GradleInternal gradle, ClassLoaderScope classLoaderScope) { buildLoader.load(rootProjectDescriptor, defaultProject, gradle, classLoaderScope); setProjectProperties(gradle.getRootProject(), new CachingPropertyApplicator()); }}public class InstantiatingBuildLoader implements BuildLoader { private final IProjectFactory projectFactory; public InstantiatingBuildLoader(IProjectFactory projectFactory) { this.projectFactory = projectFactory; } /** * Creates the {@link org.gradle.api.internal.GradleInternal} and {@link ProjectInternal} instances for the given root project, ready for the projects to be configured. */ public void load(ProjectDescriptor rootProjectDescriptor, ProjectDescriptor defaultProject, GradleInternal gradle, ClassLoaderScope baseClassLoaderScope) { createProjects(rootProjectDescriptor, gradle, baseClassLoaderScope); attachDefaultProject(defaultProject, gradle); } private void attachDefaultProject(ProjectDescriptor defaultProject, GradleInternal gradle) { gradle.setDefaultProject(gradle.getRootProject().getProjectRegistry().getProject(defaultProject.getPath())); } private void createProjects(ProjectDescriptor rootProjectDescriptor, GradleInternal gradle, ClassLoaderScope baseClassLoaderScope) { ProjectInternal rootProject = projectFactory.createProject(rootProjectDescriptor, null, gradle, baseClassLoaderScope.createChild("root-project"), baseClassLoaderScope); System.out.println("create project, rootProject: " + rootProject); gradle.setRootProject(rootProject); addProjects(rootProject, rootProjectDescriptor, gradle, baseClassLoaderScope); } } 那上面这段代码的作用就是配置gradle project层级关系，比如上层是项目根目录，也就是rootProject。
然后试各个模块，包括主模块app
日志如下：
createProject buildFile: E:\work_space\Android-Prototype\build.gradle parent: nullcreateProject buildFile: E:\work_space\Android-Prototype\app\build.gradle parent: root project 'Android-Prototype'createProject buildFile: E:\work_space\Android-Prototype\pushsdk\build.gradle parent: root project 'Android-Prototype'createProject buildFile: E:\work_space\Android-Prototype\moduletest\build.gradle parent: root project 'Android-Prototype'
然后发送project loaded通知。
gradle.getBuildListenerBroadcaster().projectsLoaded(gradle);
至此，Load步骤结束！
if (stage == null) { // Evaluate init scripts initScriptHandler.executeScripts(gradle); // Build `buildSrc`, load settings.gradle, and construct composite (if appropriate) settings = settingsLoader.findAndLoadSettings(gradle); stage = Stage.Load;} 下一篇文章来继续Configure过程。