title: Gradle Build Error - NullPointerException thrown during app:compileDebugJava gradle task
body: <p>I keep receiving this error message everytime I try to make a gradle build. I recently made a build before this and the application was created without any issue. I didn't make any changes to my build.gradle file. What is causing this?</p>
  
  <pre><code>:app:preBuild
   ......
  :app:processDebugResources
  :app:generateDebugSources
  :app:compileDebugJava FAILED
  Error:Execution failed for task ':app:compileDebugJava'.
  &gt; java.lang.NullPointerException
  </code></pre>
  
  <p>I am using Android Studio version 0.8.1</p>
  
  <p>Here is the gradle stacktrace:</p>
  
  <pre><code>* Exception is:
  org.gradle.api.tasks.TaskExecutionException: Execution failed for task ':app:compileDebugJava'.
      at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeActions(ExecuteActionsTaskExecuter.java:69)
      at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.execute(ExecuteActionsTaskExecuter.java:46)
      at org.gradle.api.internal.tasks.execution.PostExecutionAnalysisTaskExecuter.execute(PostExecutionAnalysisTaskExecuter.java:35)
      at org.gradle.api.internal.tasks.execution.SkipUpToDateTaskExecuter.execute(SkipUpToDateTaskExecuter.java:64)
      at org.gradle.api.internal.tasks.execution.ValidatingTaskExecuter.execute(ValidatingTaskExecuter.java:58)
      at org.gradle.api.internal.tasks.execution.SkipEmptySourceFilesTaskExecuter.execute(SkipEmptySourceFilesTaskExecuter.java:42)
      at org.gradle.api.internal.tasks.execution.SkipTaskWithNoActionsExecuter.execute(SkipTaskWithNoActionsExecuter.java:52)
      at org.gradle.api.internal.tasks.execution.SkipOnlyIfTaskExecuter.execute(SkipOnlyIfTaskExecuter.java:53)
      at org.gradle.api.internal.tasks.execution.ExecuteAtMostOnceTaskExecuter.execute(ExecuteAtMostOnceTaskExecuter.java:43)
      at org.gradle.api.internal.AbstractTask.executeWithoutThrowingTaskFailure(AbstractTask.java:289)
      at org.gradle.execution.taskgraph.AbstractTaskPlanExecutor$TaskExecutorWorker.executeTask(AbstractTaskPlanExecutor.java:79)
      at org.gradle.execution.taskgraph.AbstractTaskPlanExecutor$TaskExecutorWorker.processTask(AbstractTaskPlanExecutor.java:63)
      at org.gradle.execution.taskgraph.AbstractTaskPlanExecutor$TaskExecutorWorker.run(AbstractTaskPlanExecutor.java:51)
      at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor.process(DefaultTaskPlanExecutor.java:23)
      at org.gradle.execution.taskgraph.DefaultTaskGraphExecuter.execute(DefaultTaskGraphExecuter.java:86)
      at org.gradle.execution.SelectedTaskExecutionAction.execute(SelectedTaskExecutionAction.java:29)
      at org.gradle.execution.DefaultBuildExecuter.execute(DefaultBuildExecuter.java:61)
      at org.gradle.execution.DefaultBuildExecuter.access$200(DefaultBuildExecuter.java:23)
      at org.gradle.execution.DefaultBuildExecuter$2.proceed(DefaultBuildExecuter.java:67)
      at org.gradle.execution.DryRunBuildExecutionAction.execute(DryRunBuildExecutionAction.java:32)
      at org.gradle.execution.DefaultBuildExecuter.execute(DefaultBuildExecuter.java:61)
      at org.gradle.execution.DefaultBuildExecuter.execute(DefaultBuildExecuter.java:54)
      at org.gradle.initialization.DefaultGradleLauncher.doBuildStages(DefaultGradleLauncher.java:166)
      at org.gradle.initialization.DefaultGradleLauncher.doBuild(DefaultGradleLauncher.java:113)
      at org.gradle.initialization.DefaultGradleLauncher.run(DefaultGradleLauncher.java:81)
      at org.gradle.launcher.exec.InProcessBuildActionExecuter$DefaultBuildController.run(InProcessBuildActionExecuter.java:64)
      at org.gradle.launcher.cli.ExecuteBuildAction.run(ExecuteBuildAction.java:33)
      at org.gradle.launcher.cli.ExecuteBuildAction.run(ExecuteBuildAction.java:24)
      at org.gradle.launcher.exec.InProcessBuildActionExecuter.execute(InProcessBuildActionExecuter.java:35)
      at org.gradle.launcher.exec.InProcessBuildActionExecuter.execute(InProcessBuildActionExecuter.java:26)
      at org.gradle.launcher.cli.RunBuildAction.run(RunBuildAction.java:50)
      at org.gradle.internal.Actions$RunnableActionAdapter.execute(Actions.java:171)
      at org.gradle.launcher.cli.CommandLineActionFactory$ParseAndBuildAction.execute(CommandLineActionFactory.java:201)
      at org.gradle.launcher.cli.CommandLineActionFactory$ParseAndBuildAction.execute(CommandLineActionFactory.java:174)
      at org.gradle.launcher.cli.CommandLineActionFactory$WithLogging.execute(CommandLineActionFactory.java:170)
      at org.gradle.launcher.cli.CommandLineActionFactory$WithLogging.execute(CommandLineActionFactory.java:139)
      at org.gradle.launcher.cli.ExceptionReportingAction.execute(ExceptionReportingAction.java:33)
      at org.gradle.launcher.cli.ExceptionReportingAction.execute(ExceptionReportingAction.java:22)
      at org.gradle.launcher.Main.doAction(Main.java:46)
      at org.gradle.launcher.bootstrap.EntryPoint.run(EntryPoint.java:45)
      at org.gradle.launcher.Main.main(Main.java:37)
      at org.gradle.launcher.bootstrap.ProcessBootstrap.runNoExit(ProcessBootstrap.java:50)
      at org.gradle.launcher.bootstrap.ProcessBootstrap.run(ProcessBootstrap.java:32)
      at org.gradle.launcher.GradleMain.main(GradleMain.java:23)
      at org.gradle.wrapper.BootstrapMainStarter.start(BootstrapMainStarter.java:33)
      at org.gradle.wrapper.WrapperExecutor.execute(WrapperExecutor.java:130)
      at org.gradle.wrapper.GradleWrapperMain.main(GradleWrapperMain.java:48)
  Caused by: java.lang.RuntimeException: java.lang.NullPointerException
      at com.sun.tools.javac.main.Main.compile(Main.java:469)
      at com.sun.tools.javac.api.JavacTaskImpl.call(JavacTaskImpl.java:132)
      at org.gradle.api.internal.tasks.compile.jdk6.Jdk6JavaCompiler.execute(Jdk6JavaCompiler.java:45)
      at org.gradle.api.internal.tasks.compile.jdk6.Jdk6JavaCompiler.execute(Jdk6JavaCompiler.java:38)
      at org.gradle.api.internal.tasks.compile.NormalizingJavaCompiler.delegateAndHandleErrors(NormalizingJavaCompiler.java:96)
      at org.gradle.api.internal.tasks.compile.NormalizingJavaCompiler.execute(NormalizingJavaCompiler.java:49)
      at org.gradle.api.internal.tasks.compile.NormalizingJavaCompiler.execute(NormalizingJavaCompiler.java:35)
      at org.gradle.api.internal.tasks.compile.DelegatingJavaCompiler.execute(DelegatingJavaCompiler.java:29)
      at org.gradle.api.internal.tasks.compile.DelegatingJavaCompiler.execute(DelegatingJavaCompiler.java:20)
      at org.gradle.api.internal.tasks.compile.CleaningJavaCompilerSupport.execute(CleaningJavaCompilerSupport.java:33)
      at org.gradle.api.internal.tasks.compile.CleaningJavaCompilerSupport.execute(CleaningJavaCompilerSupport.java:24)
      at org.gradle.api.tasks.compile.Compile.performCompilation(Compile.java:165)
      at org.gradle.api.tasks.compile.Compile.compile(Compile.java:153)
      at org.gradle.api.tasks.compile.Compile.compile(Compile.java:87)
      at org.gradle.internal.reflect.JavaMethod.invoke(JavaMethod.java:63)
      at org.gradle.api.internal.project.taskfactory.AnnotationProcessingTaskFactory$IncrementalTaskAction.doExecute(AnnotationProcessingTaskFactory.java:236)
      at org.gradle.api.internal.project.taskfactory.AnnotationProcessingTaskFactory$StandardTaskAction.execute(AnnotationProcessingTaskFactory.java:212)
      at org.gradle.api.internal.project.taskfactory.AnnotationProcessingTaskFactory$IncrementalTaskAction.execute(AnnotationProcessingTaskFactory.java:223)
      at org.gradle.api.internal.project.taskfactory.AnnotationProcessingTaskFactory$StandardTaskAction.execute(AnnotationProcessingTaskFactory.java:201)
      at org.gradle.api.internal.AbstractTask$TaskActionWrapper.execute(AbstractTask.java:533)
      at org.gradle.api.internal.AbstractTask$TaskActionWrapper.execute(AbstractTask.java:516)
      at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeAction(ExecuteActionsTaskExecuter.java:80)
      at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeActions(ExecuteActionsTaskExecuter.java:61)
      ... 46 more
  Caused by: java.lang.NullPointerException
      at dagger.internal.codegen.Util.getAnnotation(Util.java:192)
      at dagger.internal.codegen.GraphAnalysisProcessor.process(GraphAnalysisProcessor.java:107)
      at com.sun.tools.javac.processing.JavacProcessingEnvironment.callProcessor(JavacProcessingEnvironment.java:793)
      at com.sun.tools.javac.processing.JavacProcessingEnvironment.access$200(JavacProcessingEnvironment.java:97)
      at com.sun.tools.javac.processing.JavacProcessingEnvironment$DiscoveredProcessors$ProcessorStateIterator.runContributingProcs(JavacProcessingEnvironment.java:644)
      at com.sun.tools.javac.processing.JavacProcessingEnvironment$Round.run(JavacProcessingEnvironment.java:1027)
      at com.sun.tools.javac.processing.JavacProcessingEnvironment.doProcessing(JavacProcessingEnvironment.java:1185)
      at com.sun.tools.javac.main.JavaCompiler.processAnnotations(JavaCompiler.java:1108)
      at com.sun.tools.javac.main.JavaCompiler.compile(JavaCompiler.java:824)
      at com.sun.tools.javac.main.Main.compile(Main.java:439)
      ... 68 more
  </code></pre>
  
  <p>Here is my build.gradle (its a little messy):</p>
  
  <pre><code>buildscript {
      repositories {
          mavenCentral()
          maven { url 'http://download.crashlytics.com/maven' }
      }
  
      dependencies {
          classpath 'com.jakewharton.sdkmanager:gradle-plugin:0.9.+'
          classpath 'com.crashlytics.tools.gradle:crashlytics-gradle:1.+'
      }
  }
  apply plugin: 'android-sdk-manager'
  apply plugin: 'android'
  apply plugin: 'crashlytics'
  
  repositories {
      maven { url 'http://download.crashlytics.com/maven' }
  }
  
  android {
      signingConfigs {
          release {
              storeFile file("")
              storePassword ''
              keyAlias ''
              keyPassword ''
          }
          debug {
              storeFile file('/home/andreperkins/.android/debug.keystore')
          }
      }
      //noinspection GroovyAssignabilityCheck
      compileSdkVersion Integer.parseInt(project.ANDROID_BUILD_SDK_VERSION)
      //noinspection GroovyAssignabilityCheck
      buildToolsVersion project.ANDROID_BUILD_TOOLS_VERSION
      defaultConfig {
          applicationId 'com.liveauctioneers.and'
          //noinspection GroovyAssignabilityCheck
          minSdkVersion Integer.parseInt(project.ANDROID_BUILD_MIN_SDK_VERSION)
          //noinspection GroovyAssignabilityCheck
          targetSdkVersion Integer.parseInt(project.ANDROID_BUILD_TARGET_SDK_VERSION)
          versionCode 7
          versionName '3.0'
          testInstrumentationRunner 'com.google.android.apps.common.testing.testrunner.GoogleInstrumentationTestRunner'
      }
      buildTypes {
          release {
              runProguard false
              proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
              //noinspection GroovyAssignabilityCheck
              signingConfig signingConfigs.release
          }
          debug {
              applicationIdSuffix '.debug'
              versionNameSuffix '-DEBUG'
              zipAlign false
          }
          qa {
              debuggable false
              jniDebugBuild false
              renderscriptDebugBuild false
              runProguard false
              applicationIdSuffix '.qa'
              versionNameSuffix '-QA'
              zipAlign true
              //noinspection GroovyAssignabilityCheck
              signingConfig signingConfigs.release
          }
      }
      productFlavors {
      }
      compileOptions {
          sourceCompatibility JavaVersion.VERSION_1_7
          targetCompatibility JavaVersion.VERSION_1_7
      }
      packagingOptions {
          exclude 'LICENSE.txt'
          exclude 'META-INF/services/javax.annotation.processing.Processor'
      }
  }
  
  dependencies {
      compile fileTree(dir: 'libs', include: ['*.jar'])
      compile project(':facebook')
      provided 'com.squareup.dagger:dagger-compiler:1.2.1'
      //mockito dependencies
      androidTestCompile files('libs/dexmaker-mockito-1.0.jar')
      androidTestCompile 'org.mockito:mockito-core:1.9.5'
      androidTestCompile files('libs/dexmaker-1.0.jar')
      //espresso dependencies
      /*androidTestCompile files('libs/espresso-1.1.jar')
      androidTestCompile files('libs/testrunner-1.1.jar')
      androidTestCompile files('libs/testrunner-runtime-1.1.jar')
      */ androidTestCompile 'com.google.guava:guava:16.0'
      /*androidTestCompile 'org.hamcrest:hamcrest-core:1.1'
      androidTestCompile 'org.hamcrest:hamcrest-integration:1.1'
      androidTestCompile 'org.hamcrest:hamcrest-library:1.1'*/
      androidTestCompile 'com.squareup.spoon:spoon-client:1.1.1'
  
      androidTestCompile('com.jakewharton.espresso:espresso:1.1-r3') {
          exclude group: 'com.squareup.dagger'
      }
      compile 'com.jakewharton:butterknife:4.0.+'
      compile 'com.squareup.dagger:dagger:1.2.1'
      compile 'com.squareup.okhttp:okhttp:1.3.+'
      compile 'com.squareup.retrofit:retrofit:1.5.1'
      compile 'com.google.code.gson:gson:2.2.+'
      compile 'com.crashlytics.android:crashlytics:1.+'
      compile 'com.squareup:otto:1.3.5'
      compile 'javax.annotation:javax.annotation-api:1.2'
      compile 'com.google.code.findbugs:jsr305:1.3.9'
      // You must install or update the Support Repository through the SDK manager to use this dependency.
      compile 'com.android.support:support-v13:19.0.1'
      compile 'com.j256.ormlite:ormlite-android:4.43'
      compile 'com.j256.ormlite:ormlite-core:4.43'
  } 
  </code></pre>