External clean build gets jdt.ls out-of-sync

As reported by @xuaveneg in #306, during the execution of a build task (using maven), The errors showing in the output console are:

[Error - 10:27:32] 2 oct. 2017 10:26:41 JavaBuilder handling CoreException
File not found: [filename].
org.eclipse.core.runtime.CoreException: File not found: [filename].
	at org.eclipse.core.internal.filesystem.Policy.error(Policy.java:45)
	at org.eclipse.core.internal.filesystem.local.LocalFile.openInputStream(LocalFile.java:406)
	at org.eclipse.core.internal.localstore.FileSystemResourceManager.read(FileSystemResourceManager.java:849)
	at org.eclipse.core.internal.resources.File.getContents(File.java:277)
	at org.eclipse.jdt.internal.core.util.Util.getResourceContentsAsByteArray(Util.java:1135)
	at org.eclipse.jdt.internal.core.builder.IncrementalImageBuilder.writeClassFileCheck(IncrementalImageBuilder.java:889)
	at org.eclipse.jdt.internal.core.builder.IncrementalImageBuilder.writeClassFileContents(IncrementalImageBuilder.java:831)
	at org.eclipse.jdt.internal.core.builder.AbstractImageBuilder.writeClassFile(AbstractImageBuilder.java:860)
	at org.eclipse.jdt.internal.core.builder.AbstractImageBuilder.acceptResult(AbstractImageBuilder.java:191)
	at org.eclipse.jdt.internal.compiler.Compiler.processCompiledUnits(Compiler.java:593)
	at org.eclipse.jdt.internal.compiler.Compiler.compile(Compiler.java:462)
	at org.eclipse.jdt.internal.compiler.Compiler.compile(Compiler.java:417)
	at org.eclipse.jdt.internal.core.builder.AbstractImageBuilder.compile(AbstractImageBuilder.java:368)
	at org.eclipse.jdt.internal.core.builder.IncrementalImageBuilder.compile(IncrementalImageBuilder.java:330)
	at org.eclipse.jdt.internal.core.builder.AbstractImageBuilder.compile(AbstractImageBuilder.java:305)
	at org.eclipse.jdt.internal.core.builder.IncrementalImageBuilder.build(IncrementalImageBuilder.java:135)
	at org.eclipse.jdt.internal.core.builder.JavaBuilder.buildDeltas(JavaBuilder.java:267)
	at org.eclipse.jdt.internal.core.builder.JavaBuilder.build(JavaBuilder.java:195)
	at org.eclipse.core.internal.events.BuildManager$2.run(BuildManager.java:735)
	at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42)
	at org.eclipse.core.internal.events.BuildManager.basicBuild(BuildManager.java:206)
	at org.eclipse.core.internal.events.BuildManager.basicBuild(BuildManager.java:246)
	at org.eclipse.core.internal.events.BuildManager$1.run(BuildManager.java:301)
	at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42)
	at org.eclipse.core.internal.events.BuildManager.basicBuild(BuildManager.java:304)
	at org.eclipse.core.internal.events.BuildManager.basicBuildLoop(BuildManager.java:360)
	at org.eclipse.core.internal.events.BuildManager.build(BuildManager.java:383)
	at org.eclipse.core.internal.events.AutoBuildJob.doBuild(AutoBuildJob.java:142)
	at org.eclipse.core.internal.events.AutoBuildJob.run(AutoBuildJob.java:232)
	at org.eclipse.core.internal.jobs.Worker.run(Worker.java:56)
Caused by: java.io.FileNotFoundException: [filename] (Le chemin d’accès spécifié est introuvable)
	at java.io.FileInputStream.open0(Native Method)
	at java.io.FileInputStream.open(FileInputStream.java:195)
	at java.io.FileInputStream.<init>(FileInputStream.java:138)
	at org.eclipse.core.internal.filesystem.local.LocalFile.openInputStream(LocalFile.java:401)
	... 28 more

Running a clean build from CLI, causes a discrepancy between the jdt.ls server state and the file system. We need to handle that better.

Commencez par reproduire une compilation Maven clean depuis la CLI pendant que jdt.ls s’exécute, en utilisant la JavaBuilder CoreException signalée comme échec observé. Suivez la manière dont le serveur gère les modifications du système de fichiers pendant la compilation externe ; c’est terminé lorsque l’état de jdt.ls reste synchronisé avec le système de fichiers et que l’erreur n’apparaît plus.