Why can't I launch my LibGDX project on html?

Question

So, I made a libgdx project trough the gradle setup and programmed my game. When i launch it on desktop, everything is ok, but when I try to run the html I get the following error:

  :html:draftCompileGwt FAILED

  FAILURE: Build failed with an exception.

  * What went wrong:
  Execution failed for task ':html:draftCompileGwt'.
  > Process 'command 'C:\Program Files\Java\jdk1.8.0_25\bin\java.exe''
  finished with non-zero exit value 1

  * Try:
  Run with --stacktrace option to get the stack trace. Run with --info
  or --debug option to get more log output.

  BUILD FAILED

  Total time: 16.256 secs
  Process 'command 'C:\Program Files\Java\jdk1.8.0_25\bin\java.exe'' 
  finished with non-zero exit value 1

  17:40:11: External task execution finished 'superDev'.

I have searched the internet, but I haven't found anything useful.

What could be the cause of the problem?

Update:

Running with --stacktrace:

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':html:draftCompileGwt'.
> Process 'command 'C:\Program Files\Java\jdk1.8.0_25\bin\java.exe''finished with non-zero exit value 1

* Try:
Run with --info or --debug option to get more log output.

* Exception is:
org.gradle.api.tasks.TaskExecutionException: Execution failed for task ':html:draftCompileGwt'.
    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:305)
    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.tooling.internal.provider.BuildModelAction.run(BuildModelAction.java:43)
    at org.gradle.tooling.internal.provider.BuildModelAction.run(BuildModelAction.java:30)
    at org.gradle.tooling.internal.provider.ConfiguringBuildAction.run(ConfiguringBuildAction.java:119)
    at org.gradle.launcher.exec.InProcessBuildActionExecuter.execute(InProcessBuildActionExecuter.java:36)
    at org.gradle.launcher.exec.InProcessBuildActionExecuter.execute(InProcessBuildActionExecuter.java:26)
    at org.gradle.launcher.daemon.server.exec.ExecuteBuild.doBuild(ExecuteBuild.java:47)
    at org.gradle.launcher.daemon.server.exec.BuildCommandOnly.execute(BuildCommandOnly.java:34)
    at org.gradle.launcher.daemon.server.exec.DaemonCommandExecution.proceed(DaemonCommandExecution.java:119)
    at org.gradle.launcher.daemon.server.exec.WatchForDisconnection.execute(WatchForDisconnection.java:35)
    at org.gradle.launcher.daemon.server.exec.DaemonCommandExecution.proceed(DaemonCommandExecution.java:119)
    at org.gradle.launcher.daemon.server.exec.ResetDeprecationLogger.execute(ResetDeprecationLogger.java:24)
    at org.gradle.launcher.daemon.server.exec.DaemonCommandExecution.proceed(DaemonCommandExecution.java:119)
    at org.gradle.launcher.daemon.server.exec.StartStopIfBuildAndStop.execute(StartStopIfBuildAndStop.java:33)
    at org.gradle.launcher.daemon.server.exec.DaemonCommandExecution.proceed(DaemonCommandExecution.java:119)
    at org.gradle.launcher.daemon.server.exec.ForwardClientInput$2.call(ForwardClientInput.java:71)
    at org.gradle.launcher.daemon.server.exec.ForwardClientInput$2.call(ForwardClientInput.java:69)
    at org.gradle.util.Swapper.swap(Swapper.java:38)
    at org.gradle.launcher.daemon.server.exec.ForwardClientInput.execute(ForwardClientInput.java:69)
    at org.gradle.launcher.daemon.server.exec.DaemonCommandExecution.proceed(DaemonCommandExecution.java:119)
    at org.gradle.launcher.daemon.server.exec.LogToClient.doBuild(LogToClient.java:60)
    at org.gradle.launcher.daemon.server.exec.BuildCommandOnly.execute(BuildCommandOnly.java:34)
    at org.gradle.launcher.daemon.server.exec.DaemonCommandExecution.proceed(DaemonCommandExecution.java:119)
    at org.gradle.launcher.daemon.server.exec.EstablishBuildEnvironment.doBuild(EstablishBuildEnvironment.java:70)
    at org.gradle.launcher.daemon.server.exec.BuildCommandOnly.execute(BuildCommandOnly.java:34)
    at org.gradle.launcher.daemon.server.exec.DaemonCommandExecution.proceed(DaemonCommandExecution.java:119)
    at org.gradle.launcher.daemon.server.exec.DaemonHygieneAction.execute(DaemonHygieneAction.java:39)
    at org.gradle.launcher.daemon.server.exec.DaemonCommandExecution.proceed(DaemonCommandExecution.java:119)
    at org.gradle.launcher.daemon.server.exec.StartBuildOrRespondWithBusy$1.run(StartBuildOrRespondWithBusy.java:46)
    at org.gradle.launcher.daemon.server.DaemonStateCoordinator$1.run(DaemonStateCoordinator.java:246)
    at org.gradle.internal.concurrent.DefaultExecutorFactory$StoppableExecutorImpl$1.run(DefaultExecutorFactory.java:64)
Caused by: org.gradle.process.internal.ExecException: Process 'command 'C:\Program Files\Java\jdk1.8.0_25\bin\java.exe'' finished with non-zero exit value 1
    at org.gradle.process.internal.DefaultExecHandle$ExecResultImpl.assertNormalExitValue(DefaultExecHandle.java:365)
    at org.gradle.process.internal.DefaultJavaExecAction.execute(DefaultJavaExecAction.java:31)
    at org.gradle.api.internal.file.DefaultFileOperations.javaexec(DefaultFileOperations.java:145)
    at org.gradle.api.internal.project.AbstractProject.javaexec(AbstractProject.java:784)
    at org.gradle.api.internal.project.AbstractProject.javaexec(AbstractProject.java:780)
    at de.richsource.gradle.plugins.gwt.AbstractGwtActionTask.exec(AbstractGwtActionTask.java:72)
    at org.gradle.internal.reflect.JavaMethod.invoke(JavaMethod.java:63)
    at org.gradle.api.internal.project.taskfactory.AnnotationProcessingTaskFactory$StandardTaskAction.doExecute(AnnotationProcessingTaskFactory.java:218)
    at org.gradle.api.internal.project.taskfactory.AnnotationProcessingTaskFactory$StandardTaskAction.execute(AnnotationProcessingTaskFactory.java:211)
    at org.gradle.api.internal.project.taskfactory.AnnotationProcessingTaskFactory$StandardTaskAction.execute(AnnotationProcessingTaskFactory.java:200)
    at org.gradle.api.internal.AbstractTask$TaskActionWrapper.execute(AbstractTask.java:579)
    at org.gradle.api.internal.AbstractTask$TaskActionWrapper.execute(AbstractTask.java:562)
    at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeAction(ExecuteActionsTaskExecuter.java:80)
    at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeActions(ExecuteActionsTaskExecuter.java:61)
    ... 55 more


BUILD FAILED

Answer 1

Try to run the task with --debug, as suggested by P.T., but save all output into a file. Then open the output file in some text editor and search for "Error". The error itself could be far away from the end of the file. So, your terminal application could not have enough buffers to save it completely, that is why there is the need for a file.

For example for me GWT was not able to compile some classes, because of missing implementation of some java methods in GWT itself. It just silently continue to compile, however strict mode for compiler was enabled (maybe there is a bug in gradle-gwt). And at the end there was no readable output. But the above instruction helped me.

Answer 2

I had the same problem. In my case, I had an extra package located in a different folder of the main java class. The solution was edit the .gwt.xml file and add my other source package.

The original code was:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE module PUBLIC "-//Google Inc.//DTD Google Web Toolkit trunk//EN" "http://google-web-toolkit.googlecode.com/svn/trunk/distro-source/core/src/gwt-module.dtd">
<module>
    <source path="com/jds/domino" />
</module>

And I added:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE module PUBLIC "-//Google Inc.//DTD Google Web Toolkit trunk//EN" "http://google-web-toolkit.googlecode.com/svn/trunk/distro-source/core/src/gwt-module.dtd">
<module>
    <source path="com/jds/domino" />
    <source path="com/jds/splash" />
</module>