Fix the error 'Invalid project description' caused by incorrect glob patterns for Windows paths

org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/managers/EclipseProjectImporter.java

@@ -48,7 +48,15 @@ public boolean applies(IProgressMonitor monitor) throws CoreException {
 					.addExclusions("**/bin");//default Eclipse build dir
 			for (IProject project : ProjectUtils.getAllProjects(false)) {
 				File projectFile = project.getLocation().toFile();
-				eclipseDetector.addExclusions(projectFile.getAbsolutePath());
+				/**
+				 * The exclusion pattern will be used as a regular expression
+				 * that matches the files or folders to be excluded. On Windows,
+				 * the path separator (\) is a special character in regular
+				 * expressions, so it needs to be escaped with another backslash (\)
+				 * to be treated literally. For example, to exclude the folder
+				 * C:\Users\Hello, the exclusion pattern should be C:\\Users\\Hello.
+				 */
+				eclipseDetector.addExclusions(projectFile.getAbsolutePath().replace("\\", "\\\\"));
 			}
 			directories = eclipseDetector.scan(monitor);
 		}

org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/managers/GradleProjectImporter.java

@@ -148,7 +148,7 @@ public boolean applies(IProgressMonitor monitor) throws CoreException {
 			for (IProject project : ProjectUtils.getAllProjects()) {
 				if (!ProjectUtils.isGradleProject(project)) {
 					String path = project.getLocation().toOSString();
-					gradleDetector.addExclusions(path);
+					gradleDetector.addExclusions(path.replace("\\", "\\\\"));
 				}
 			}
 			directories = gradleDetector.scan(monitor);
@@ -552,15 +552,11 @@ private static boolean checkGradlePersistence(IProject project, File projectDir)
 			if (persistentFile.exists()) {
 				long modified = persistentFile.lastModified();
 				if (projectDir.exists()) {
-					File[] files = projectDir.listFiles(new FilenameFilter() {
-
-						@Override
-						public boolean accept(File dir, String name) {
-							if (name != null && GradleBuildSupport.GRADLE_FILE_EXT.matcher(name).matches()) {
-								return new File(dir, name).lastModified() > modified;
-							}
-							return false;
+					File[] files = projectDir.listFiles((FilenameFilter) (dir, name) -> {
+						if (name != null && GradleBuildSupport.GRADLE_FILE_EXT.matcher(name).matches()) {
+							return new File(dir, name).lastModified() > modified;
 						}
+						return false;
 					});
 					shouldSynchronize = files != null && files.length > 0;
 				}

org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/managers/MavenProjectImporter.java

@@ -99,7 +99,7 @@ public boolean applies(IProgressMonitor monitor) throws OperationCanceledExcepti
 			for (IProject project : ProjectUtils.getAllProjects()) {
 				if (!ProjectUtils.isMavenProject(project)) {
 					String path = project.getLocation().toOSString();
-					mavenDetector.addExclusions(path);
+					mavenDetector.addExclusions(path.replace("\\", "\\\\"));
 				}
 			}
 			directories = mavenDetector.scan(monitor);

org.eclipse.jdt.ls.tests/src/org/eclipse/jdt/ls/core/internal/managers/EclipseProjectImporterTest.java

@@ -281,6 +281,18 @@ public void testNullAnalysis() throws Exception {
 		}
 	}
 
+	@Test
+	public void DoNotDuplicateImportProject() throws Exception {
+		String name = "hello";
+		importProjects("eclipse/"+name);
+		IProject project = getProject(name );
+		assertIsJavaProject(project);
+		EclipseProjectImporter importer = new EclipseProjectImporter();
+		importer.initialize(project.getLocation().toFile());
+		boolean hasUnimportedProjects = importer.applies(new NullProgressMonitor());
+		assertFalse(hasUnimportedProjects);
+	}
+
 	@After
 	public void after() {
 		importer = null;

org.eclipse.jdt.ls.tests/src/org/eclipse/jdt/ls/core/internal/managers/GradleProjectImporterTest.java

@@ -565,6 +565,23 @@ public void avoidImportDuplicatedProjects() throws Exception {
 		}
 	}
 
+	@Test
+	public void avoidImportDuplicatedProjects2() throws Exception {
+		try {
+			this.preferences.setImportGradleEnabled(false);
+			importProjects("multi-buildtools");
+			IProject project = getProject("multi-build-tools");
+			assertIsJavaProject(project);
+			GradleProjectImporter importer = new GradleProjectImporter();
+			importer.initialize(project.getLocation().toFile());
+
+			this.preferences.setImportGradleEnabled(true);
+			assertFalse(importer.applies(null));
+		} finally {
+			this.preferences.setImportGradleEnabled(true);
+		}
+	}
+
 	@Test
 	public void testProtoBufSupport() throws Exception {
 		try {

org.eclipse.jdt.ls.tests/src/org/eclipse/jdt/ls/core/internal/managers/MavenProjectImporterTest.java

@@ -378,6 +378,23 @@ public void avoidImportDuplicatedProjects() throws Exception {
 		}
 	}
 
+	@Test
+	public void avoidImportDuplicatedProjects2() throws Exception {
+		try {
+			this.preferences.setImportMavenEnabled(false);
+			importProjects("multi-buildtools");
+			IProject project = WorkspaceHelper.getProject("multi-buildtools");
+			assertIsJavaProject(project);
+			MavenProjectImporter importer = new MavenProjectImporter();
+			importer.initialize(project.getLocation().toFile());
+
+			this.preferences.setImportMavenEnabled(true);
+			assertFalse(importer.applies(null));
+		} finally {
+			this.preferences.setImportMavenEnabled(true);
+		}
+	}
+
 	// https://github.com/redhat-developer/vscode-java/issues/2712
 	@Test
 	public void testNullAnalysisDisabled() throws Exception {