run boot version validations in their own executor to avoid blocking the main message thread

headless-services/spring-boot-language-server/src/main/java/org/springframework/ide/vscode/boot/app/BootVersionValidationEngine.java

@@ -0,0 +1,51 @@
+/*******************************************************************************
+ * Copyright (c) 2022 VMware, Inc.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * https://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *     VMware, Inc. - initial API and implementation
+ *******************************************************************************/
+package org.springframework.ide.vscode.boot.app;
+
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+
+import org.springframework.ide.vscode.commons.java.IJavaProject;
+import org.springframework.ide.vscode.commons.languageserver.java.ProjectObserver;
+import org.springframework.stereotype.Component;
+
+@Component
+public class BootVersionValidationEngine {
+
+	private final BootVersionValidator bootVersionValidator;
+	private final ExecutorService validationExecutor = Executors.newFixedThreadPool(3);
+	
+	public BootVersionValidationEngine(ProjectObserver observer, BootVersionValidator bootVersionValidator) {
+		this.bootVersionValidator = bootVersionValidator;
+		
+		observer.addListener(new ProjectObserver.Listener() {
+
+			@Override
+			public void deleted(IJavaProject project) {
+			}
+
+			@Override
+			public void created(IJavaProject project) {
+				validate(project);
+			}
+
+			@Override
+			public void changed(IJavaProject project) {
+
+			}
+		});
+	}
+	
+	public void validate(IJavaProject project) {
+		validationExecutor.submit(() -> bootVersionValidator.validate(project));
+	}
+
+}

headless-services/spring-boot-language-server/src/main/java/org/springframework/ide/vscode/boot/app/BootVersionValidator.java

@@ -14,14 +14,13 @@ import org.eclipse.lsp4j.TextDocumentIdentifier;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.ide.vscode.boot.validation.generations.ProjectVersionDiagnosticProvider;
-import org.springframework.ide.vscode.boot.validation.generations.ProjectVersionDiagnosticProvider.DiagnosticResult;
 import org.springframework.ide.vscode.boot.validation.generations.SpringIoProjectsProvider;
 import org.springframework.ide.vscode.boot.validation.generations.SpringProjectsClient;
 import org.springframework.ide.vscode.boot.validation.generations.SpringProjectsProvider;
 import org.springframework.ide.vscode.boot.validation.generations.VersionValidators;
+import org.springframework.ide.vscode.boot.validation.generations.ProjectVersionDiagnosticProvider.DiagnosticResult;
 import org.springframework.ide.vscode.boot.validation.generations.preferences.VersionValidationPreferences;
 import org.springframework.ide.vscode.commons.java.IJavaProject;
-import org.springframework.ide.vscode.commons.languageserver.java.ProjectObserver;
 import org.springframework.ide.vscode.commons.languageserver.util.SimpleLanguageServer;
 import org.springframework.stereotype.Component;
 
@@ -32,25 +31,9 @@ public class BootVersionValidator {
 	private SimpleLanguageServer server;
 	private BootJavaConfig config;
 	
-	public BootVersionValidator(SimpleLanguageServer server, ProjectObserver observer, BootJavaConfig config) {
+	public BootVersionValidator(SimpleLanguageServer server, BootJavaConfig config) {
 		this.server = server;
 		this.config = config;
-		observer.addListener(new ProjectObserver.Listener() {
-
-			@Override
-			public void deleted(IJavaProject project) {
-			}
-
-			@Override
-			public void created(IJavaProject project) {
-				validate(project);
-			}
-
-			@Override
-			public void changed(IJavaProject project) {
-
-			}
-		});
 	}
 	
 	public void validate(IJavaProject project) {

headless-services/spring-boot-language-server/src/main/java/org/springframework/ide/vscode/boot/java/BootJavaLanguageServerComponents.java

@@ -23,7 +23,7 @@ import org.slf4j.LoggerFactory;
 import org.springframework.context.ApplicationContext;
 import org.springframework.ide.vscode.boot.app.BootJavaConfig;
 import org.springframework.ide.vscode.boot.app.BootLanguageServerParams;
-import org.springframework.ide.vscode.boot.app.BootVersionValidator;
+import org.springframework.ide.vscode.boot.app.BootVersionValidationEngine;
 import org.springframework.ide.vscode.boot.app.SpringSymbolIndex;
 import org.springframework.ide.vscode.boot.java.annotations.AnnotationHierarchyAwareLookup;
 import org.springframework.ide.vscode.boot.java.autowired.AutowiredHoverProvider;
@@ -202,7 +202,7 @@ public class BootJavaLanguageServerComponents implements LanguageServerComponent
 		reconcileEngine = new BootJavaReconcileEngine(projectFinder, new JavaReconciler[] {
 				jdtReconciler,
 				rewriteJavaReconciler
-		}, documents, appContext.getBean(BootVersionValidator.class));
+		}, documents, appContext.getBean(BootVersionValidationEngine.class));
 		
 		codeActionProvider = new BootJavaCodeActionProvider(
 				projectFinder,

headless-services/spring-boot-language-server/src/main/java/org/springframework/ide/vscode/boot/java/handlers/BootJavaReconcileEngine.java

@@ -17,7 +17,6 @@ import java.util.Collection;
 import java.util.Collections;
 import java.util.List;
 import java.util.Map;
-import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.function.Function;
 import java.util.stream.Collectors;
@@ -26,7 +25,7 @@ import java.util.stream.Stream;
 import org.eclipse.lsp4j.TextDocumentIdentifier;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
-import org.springframework.ide.vscode.boot.app.BootVersionValidator;
+import org.springframework.ide.vscode.boot.app.BootVersionValidationEngine;
 import org.springframework.ide.vscode.boot.common.IJavaProjectReconcileEngine;
 import org.springframework.ide.vscode.boot.java.reconcilers.JavaReconciler;
 import org.springframework.ide.vscode.commons.java.IClasspathUtil;
@@ -41,30 +40,24 @@ import org.springframework.ide.vscode.commons.util.text.LanguageId;
 import org.springframework.ide.vscode.commons.util.text.LazyTextDocument;
 import org.springframework.ide.vscode.commons.util.text.TextDocument;
 
-import reactor.core.publisher.Mono;
-import reactor.core.scheduler.Scheduler;
-import reactor.core.scheduler.Schedulers;
-
 /**
  * @author Martin Lippert
  */
 public class BootJavaReconcileEngine implements IReconcileEngine, IJavaProjectReconcileEngine {
 		
 	private static final Logger log = LoggerFactory.getLogger(BootJavaReconcileEngine.class);
-	private Scheduler bootVersionValidationScheduler = Schedulers.newBoundedElastic(3, Integer.MAX_VALUE, "Boot-Version-Validation", 10);
-
 
 	private final SimpleTextDocumentService documents;
 	private final JavaProjectFinder projectFinder; 
 	private JavaReconciler[] javaReconcilers;
 
-	private BootVersionValidator bootVersionValidator;
+	private BootVersionValidationEngine bootVersionValidationEngine;
 	
-	public BootJavaReconcileEngine(JavaProjectFinder projectFinder, JavaReconciler[] javaReconcilers, SimpleTextDocumentService documents, BootVersionValidator bootVersionValidator) {
+	public BootJavaReconcileEngine(JavaProjectFinder projectFinder, JavaReconciler[] javaReconcilers, SimpleTextDocumentService documents, BootVersionValidationEngine bootVersionValidator) {
 		this.documents = documents;
 		this.projectFinder = projectFinder;
 		this.javaReconcilers = javaReconcilers;
-		this.bootVersionValidator = bootVersionValidator;
+		this.bootVersionValidationEngine = bootVersionValidator;
 	}
 
 	@Override
@@ -125,9 +118,10 @@ public class BootJavaReconcileEngine implements IReconcileEngine, IJavaProjectRe
 
 	@Override
 	public void reconcile(IJavaProject project, Function<TextDocument, IProblemCollector> problemCollectorFactory) {
-		if (bootVersionValidator != null) {
-			Mono.fromFuture(CompletableFuture.runAsync(() -> bootVersionValidator.validate(project))).publishOn(bootVersionValidationScheduler).subscribe();
+		if (bootVersionValidationEngine != null) {
+			bootVersionValidationEngine.validate(project);
 		}
+
 		Stream<Path> files = IClasspathUtil.getProjectJavaSourceFolders(project.getClasspath()).flatMap(folder -> {
 			try {
 				return Files.walk(folder.toPath()).filter(Files::isRegularFile);
@@ -135,6 +129,7 @@ public class BootJavaReconcileEngine implements IReconcileEngine, IJavaProjectRe
 				return Stream.empty();
 			}
 		});
+
 		Stream<TextDocumentIdentifier> docIds = files
 				.filter(f -> f.getFileName().toString().endsWith(".java"))
 				.map(f -> new TextDocumentIdentifier(f.toUri().toString()));