为什么我不能使用Google Classroom API？

Question

I have a problem with Google Developer Console and is that I can't use the new API of Google Classroom. I don't understand this because Google has given me early access to this API. When I try to do the Java Quickstart Guide that appears in the documentation, the project execution fails. In the command line appears this:

/home/usuario/eclipseWorkspace/pruebasDeClassroom/src/main/java/ClassroomQuickstart.java:41: error: cannot find symbol
    Arrays.asList(ClassroomScopes.CLASSROOM_COURSES_READONLY);
                  ^
symbol:   variable ClassroomScopes
location: class ClassroomQuickstart

1 error

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':compileJava'.
> Compilation failed; see the compiler error output for details.

And the stacktrace of the exception:

org.gradle.api.tasks.TaskExecutionException: Execution failed for task ':compileJava'.
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:306)
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:88)
at org.gradle.execution.SelectedTaskExecutionAction.execute(SelectedTaskExecutionAction.java:29)
at org.gradle.execution.DefaultBuildExecuter.execute(DefaultBuildExecuter.java:62)
at org.gradle.execution.DefaultBuildExecuter.access$200(DefaultBuildExecuter.java:23)
at org.gradle.execution.DefaultBuildExecuter$2.proceed(DefaultBuildExecuter.java:68)
at org.gradle.execution.DryRunBuildExecutionAction.execute(DryRunBuildExecutionAction.java:32)
at org.gradle.execution.DefaultBuildExecuter.execute(DefaultBuildExecuter.java:62)
at org.gradle.execution.DefaultBuildExecuter.execute(DefaultBuildExecuter.java:55)
at org.gradle.initialization.DefaultGradleLauncher.doBuildStages(DefaultGradleLauncher.java:149)
at org.gradle.initialization.DefaultGradleLauncher.doBuild(DefaultGradleLauncher.java:106)
at org.gradle.initialization.DefaultGradleLauncher.run(DefaultGradleLauncher.java:86)
at org.gradle.launcher.exec.InProcessBuildActionExecuter$DefaultBuildController.run(InProcessBuildActionExecuter.java:80)
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:36)
at org.gradle.launcher.exec.InProcessBuildActionExecuter.execute(InProcessBuildActionExecuter.java:26)
at org.gradle.launcher.cli.RunBuildAction.run(RunBuildAction.java:51)
at org.gradle.internal.Actions$RunnableActionAdapter.execute(Actions.java:169)
at org.gradle.launcher.cli.CommandLineActionFactory$ParseAndBuildAction.execute(CommandLineActionFactory.java:237)
at org.gradle.launcher.cli.CommandLineActionFactory$ParseAndBuildAction.execute(CommandLineActionFactory.java:210)
at org.gradle.launcher.cli.JavaRuntimeValidationAction.execute(JavaRuntimeValidationAction.java:35)
at org.gradle.launcher.cli.JavaRuntimeValidationAction.execute(JavaRuntimeValidationAction.java:24)
at org.gradle.launcher.cli.CommandLineActionFactory$WithLogging.execute(CommandLineActionFactory.java:206)
at org.gradle.launcher.cli.CommandLineActionFactory$WithLogging.execute(CommandLineActionFactory.java:169)
at org.gradle.launcher.cli.ExceptionReportingAction.execute(ExceptionReportingAction.java:33)
at org.gradle.launcher.cli.ExceptionReportingAction.execute(ExceptionReportingAction.java:22)
at org.gradle.launcher.Main.doAction(Main.java:33)
at org.gradle.launcher.bootstrap.EntryPoint.run(EntryPoint.java:45)
at org.gradle.launcher.bootstrap.ProcessBootstrap.runNoExit(ProcessBootstrap.java:54)
at org.gradle.launcher.bootstrap.ProcessBootstrap.run(ProcessBootstrap.java:35)
at org.gradle.launcher.GradleMain.main(GradleMain.java:23)
Caused by:
org.gradle.api.internal.tasks.compile.CompilationFailedException: Compilation failed; see the compiler error output for details.
at org.gradle.api.internal.tasks.compile.JdkJavaCompiler.execute(JdkJavaCompiler.java:44)
at org.gradle.api.internal.tasks.compile.JdkJavaCompiler.execute(JdkJavaCompiler.java:35)
at org.gradle.api.internal.tasks.compile.NormalizingJavaCompiler.delegateAndHandleErrors(NormalizingJavaCompiler.java:97)
at org.gradle.api.internal.tasks.compile.NormalizingJavaCompiler.execute(NormalizingJavaCompiler.java:50)
at org.gradle.api.internal.tasks.compile.NormalizingJavaCompiler.execute(NormalizingJavaCompiler.java:36)
at org.gradle.api.internal.tasks.compile.CleaningJavaCompilerSupport.execute(CleaningJavaCompilerSupport.java:34)
at org.gradle.api.internal.tasks.compile.CleaningJavaCompilerSupport.execute(CleaningJavaCompilerSupport.java:25)
at org.gradle.api.tasks.compile.JavaCompile.performCompilation(JavaCompile.java:156)
at org.gradle.api.tasks.compile.JavaCompile.compile(JavaCompile.java:136)
at org.gradle.api.tasks.compile.JavaCompile.compile(JavaCompile.java:90)
at org.gradle.internal.reflect.JavaMethod.invoke(JavaMethod.java:63)
at org.gradle.api.internal.project.taskfactory.AnnotationProcessingTaskFactory$IncrementalTaskAction.doExecute(AnnotationProcessingTaskFactory.java:235)
at org.gradle.api.internal.project.taskfactory.AnnotationProcessingTaskFactory$StandardTaskAction.execute(AnnotationProcessingTaskFactory.java:211)
at org.gradle.api.internal.project.taskfactory.AnnotationProcessingTaskFactory$IncrementalTaskAction.execute(AnnotationProcessingTaskFactory.java:222)
at org.gradle.api.internal.project.taskfactory.AnnotationProcessingTaskFactory$StandardTaskAction.execute(AnnotationProcessingTaskFactory.java:200)
at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeAction(ExecuteActionsTaskExecuter.java:80)
at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeActions(ExecuteActionsTaskExecuter.java:61)
... 44 more

I think that this happens because the Classroom API isn't available yet in Google Developers Console but I'm not sure. In fact, if you go to your Google Developers Console > APIs, and you search the API classroom you will not find nothing to enable. I try the Java Quickstart Guide of Gmail too and it works correctly (the Gmail API is available and I enabled for the test).

I need to know if there is a solution for this issue. Thank you for your time.

Answer 1

This problem was due to a missing import statement in the sample code:

import com.google.api.services.classroom.ClassroomScopes;

The sample is now fixed. Thanks for bringing this to our attention.

Answer 2

The scopes for the various API methods are defined in the documentation for the various REST APIs. From that documentation, it is possible to easily construct a replacement for the file:

public final class ClassroomScopes {
   // Read only access to the courses, for use in the "courses.list"
   // and "courses.get" API methods. See the documentation here:
   // https://developers.google.com/classroom/reference/rest/v1/courses/list
   // https://developers.google.com/classroom/reference/rest/v1/courses/get
   public static final String CLASSROOM_COURSES_READONLY = 
       "https://www.googleapis.com/auth/classroom.courses.readonly";

   // Prevent instantiation
   private ClassroomScopes() {}
}

... though I would encourage you to use the "SEND FEEDBACK" link on the QuickStart Java page to indicate that this wasn't working out of the box (either the file does not exist or the file exists but is not in the same package and there is a missing import for it) so that this gets fixed.