Java – Cannot compile to android (Unity)

I’m trying to compile my VR project to an Android phone.

But I keep getting the following error:

Failed to compile resources with the following parameters:
-bootclasspath "C:/Program Files (x86)/Android/android-sdk\platforms\android-26\android.jar" -d "C:\Users\**\Documents\**\**\Temp\StagingArea\bin\classes" -source 1.6 -target 1.6 -encoding UTF-8 "com\google\gvr\keyboardsupport\R.java" "com\google\gvr\permissionsupport\R.java" "com\google\vr\cardboard\R.java" "com\google\vr\keyboard\R.java" "com\***\**\ R.java" "com\unity3d\unitygvr\R.java"
warning: [options] source value 1.6 is obsolete and will be removed in a future release
warning: [options] target value 1.6 is obsolete and will be removed in a future release
warning: [options] To suppress warnings about obsolete options, use -Xlint:-options.

I

already have Android Studio and Android SDK installed, and I also have the latest version of the Java SDK

Can anyone tell me what I can do?

More bugs:

    UnityException: Resource compilation failed!
Failed to recompile android resource files. See the Console for details.
UnityEditor.Android.PostProcessor.CancelPostProcess.AbortBuild (System.String title, System.String message, System.Exception ex)
UnityEditor.Android.PostProcessor.CancelPostProcess.AbortBuild (System.String title, System.String message)
UnityEditor.Android.PostProcessor.CancelPostProcess.AbortBuildPointToConsole (System.String title, System.String message)
UnityEditor.Android.PostProcessor.Tasks.BuildResources.CompileResources (UnityEditor.Android.PostProcessor.PostProcessorContext context)
UnityEditor.Android.PostProcessor.Tasks.BuildResources.Execute (UnityEditor.Android.PostProcessor.PostProcessorContext context)
UnityEditor.Android.PostProcessor.PostProcessRunner.RunAllTasks (UnityEditor.Android.PostProcessor.PostProcessorContext context)
UnityEditor.Android.PostProcessAndroidPlayer.PostProcess (BuildTarget target, System.String stagingAreaData, System.String stagingArea, System.String playerPackage, System.String installPath, System.String companyName, System.String productName, BuildOptions options, UnityEditor.RuntimeClassRegistry usedClassRegistry, UnityEditor.BuildReporting.BuildReport report)
UnityEditor.Android.AndroidBuildPostprocessor.PostProcess (BuildPostProcessArgs args)
UnityEditor.PostprocessBuildPlayer.Postprocess (BuildTargetGroup targetGroup, BuildTarget target, System.String installPath, System.String companyName, System.String productName, Int32 width, Int32 height, BuildOptions options, UnityEditor.RuntimeClassRegistry usedClassRegistry, UnityEditor.BuildReporting.BuildReport report) (at C: /buildslave/unity/build/Editor/Mono/BuildPipeline/PostprocessBuildPlayer.cs:263)
UnityEditor.HostView:OnGUI()

    UnityException: Resource compilation failed!
Failed to recompile android resource files. See the Console for details.
UnityEditor.Android.PostProcessor.CancelPostProcess.AbortBuild (System.String title, System.String message, System.Exception ex)
UnityEditor.Android.PostProcessor.CancelPostProcess.AbortBuild (System.String title, System.String message)
UnityEditor.Android.PostProcessor.CancelPostProcess.AbortBuildPointToConsole (System.String title, System.String message)
UnityEditor.Android.PostProcessor.Tasks.BuildResources.CompileResources (UnityEditor.Android.PostProcessor.PostProcessorContext context)
UnityEditor.Android.PostProcessor.Tasks.BuildResources.Execute (UnityEditor.Android.PostProcessor.PostProcessorContext context)
UnityEditor.Android.PostProcessor.PostProcessRunner.RunAllTasks (UnityEditor.Android.PostProcessor.PostProcessorContext context)
UnityEditor.Android.PostProcessAndroidPlayer.PostProcess (BuildTarget target, System.String stagingAreaData, System.String stagingArea, System.String playerPackage, System.String installPath, System.String companyName, System.String productName, BuildOptions options, UnityEditor.RuntimeClassRegistry usedClassRegistry, UnityEditor.BuildReporting.BuildReport report)
UnityEditor.Android.AndroidBuildPostprocessor.PostProcess (BuildPostProcessArgs args)
UnityEditor.PostprocessBuildPlayer.Postprocess (BuildTargetGroup targetGroup, BuildTarget target, System.String installPath, System.String companyName, System.String productName, Int32 width, Int32 height, BuildOptions options, UnityEditor.RuntimeClassRegistry usedClassRegistry, UnityEditor.BuildReporting.BuildReport report) (at C: /buildslave/unity/build/Editor/Mono/BuildPipeline/PostprocessBuildPlayer.cs:263)
UnityEditor.HostView:OnGUI()

I think this is caused by JDK 9. I see the same error on my home computer with JDK 9. I don’t see the error at work, I have JDK 8 installed. (Specifically, I did this using JDK 8 Update 131, 64-bit.) )

If I read the error message correctly, then it looks like something in Unity or the android toolchain is requesting to compile the source files against Java 6.0 (1.6). This is about 11 years old, so it has been marked as deprecated in JDK 9. Downgrading to JDK 8 should fix it temporarily. Eventually, the toolchain will need to be updated to support the new version.