Added restart java language server command

Signed-off-by: Alexander Chen <[email protected]>

README.md

@@ -106,6 +106,7 @@ The following commands are available:
 - `Java: List All Java Source Paths`: lists all the Java source paths recognized by the Java Language Server workspace.
 - `Java: Show Build Job Status`: shows the Java Language Server job status in Visual Studio Code terminal.
 - `Java: Go to Super Implementation`: goes to the super implementation for the current selected symbol in editor.
+- `Java: Restart Java Language Server`: restarts the Java language server.
 
 Supported VS Code settings
 ==========================

package.json

@@ -1031,6 +1031,11 @@
         "command": "java.action.changeBaseType",
         "title": "%java.action.changeBaseType%",
         "category": "Java"
+      },
+      {
+        "command": "java.language.server.restart",
+        "title": "%java.language.server.restart%",
+        "category": "Java"
       }
     ],
     "keybindings": [

package.nls.json

@@ -21,5 +21,6 @@
 	"java.action.showClassHierarchy": "Show Class Hierarchy",
 	"java.action.showSupertypeHierarchy": "Show Supertype Hierarchy",
 	"java.action.showSubtypeHierarchy": "Show Subtype Hierarchy",
-	"java.action.changeBaseType": "Base on this Type"
+	"java.action.changeBaseType": "Base on this Type",
+	"java.language.server.restart": "Restart Java Language Server"
 }

src/commands.ts

@@ -259,6 +259,10 @@ export namespace Commands {
      * Command to switch between standard mode and lightweight mode.
      */
     export const SWITCH_SERVER_MODE = 'java.server.mode.switch';
+	/**
+     * Command to restart client connection to language server.
+     */
+	export const RESTART_LANGUAGE_SERVER = 'java.language.server.restart';
 
     export const LEARN_MORE_ABOUT_REFACTORING = '_java.learnMoreAboutRefactorings';
 

src/extension.ts

@@ -8,7 +8,7 @@ import { workspace, extensions, ExtensionContext, window, commands, ViewColumn,
 import { ExecuteCommandParams, ExecuteCommandRequest, LanguageClientOptions, RevealOutputChannelOn, ErrorHandler, Message, ErrorAction, CloseAction, DidChangeConfigurationNotification, CancellationToken, CodeActionRequest, CodeActionParams, Command } from 'vscode-languageclient';
 import { LanguageClient } from 'vscode-languageclient/node';
 import { collectJavaExtensions, isContributedPartUpdated } from './plugin';
-import { HEAP_DUMP_LOCATION, prepareExecutable } from './javaServerStarter';
+import { DEBUG, HEAP_DUMP_LOCATION, prepareExecutable } from './javaServerStarter';
 import * as requirements from './requirements';
 import { initialize as initializeRecommendation } from './recommendation';
 import { Commands } from './commands';
@@ -167,6 +167,7 @@ export function activate(context: ExtensionContext): Promise<ExtensionAPI> {
 	context.subscriptions.push(commands.registerCommand(Commands.NOT_COVERED_EXECUTION, async () => {
 		markdownPreviewProvider.show(context.asAbsolutePath(path.join('document', `_java.notCoveredExecution.md`)), 'Not Covered Maven Plugin Execution', "", context);
 	}));
+	registerRestartJavaLanguageServerCommand(context);
 
 	storagePath = context.storagePath;
 	context.subscriptions.push(commands.registerCommand(Commands.MEATDATA_FILES_GENERATION, async () => {
@@ -271,7 +272,7 @@ export function activate(context: ExtensionContext): Promise<ExtensionAPI> {
 							range: client.code2ProtocolConverter.asRange(range),
 							context: client.code2ProtocolConverter.asCodeActionContext(context)
 						};
-						const showAt  = getJavaConfiguration().get<string>("quickfix.showAt");
+						const showAt = getJavaConfiguration().get<string>("quickfix.showAt");
 						if (showAt === 'line' && range.start.line === range.end.line && range.start.character === range.end.character) {
 							const textLine = document.lineAt(params.range.start.line);
 							if (textLine !== null) {
@@ -508,7 +509,7 @@ async function workspaceContainsBuildFiles(): Promise<boolean> {
 	const inclusionPatterns: string[] = getBuildFilePatterns();
 	const inclusionPatternsFromNegatedExclusion: string[] = getInclusionPatternsFromNegatedExclusion();
 	if (inclusionPatterns.length > 0 && inclusionPatternsFromNegatedExclusion.length > 0 &&
-			(await workspace.findFiles(convertToGlob(inclusionPatterns, inclusionPatternsFromNegatedExclusion), null, 1 /*maxResults*/)).length > 0) {
+		(await workspace.findFiles(convertToGlob(inclusionPatterns, inclusionPatternsFromNegatedExclusion), null, 1 /*maxResults*/)).length > 0) {
 		return true;
 	}
 
@@ -545,7 +546,7 @@ async function ensureNoBuildToolConflicts(context: ExtensionContext, clientOptio
 			clientOptions.initializationOptions.settings.java.import.maven.enabled = false;
 			context.workspaceState.update(ACTIVE_BUILD_TOOL_STATE, "gradle");
 		} else {
-			throw new Error ("Unknown build tool: " + activeBuildTool); // unreachable
+			throw new Error("Unknown build tool: " + activeBuildTool); // unreachable
 		}
 	}
 
@@ -801,7 +802,7 @@ function openLogFile(logFile, openingFailureWarning: string, column: ViewColumn
 			if (!doc) {
 				return false;
 			}
-			return window.showTextDocument(doc, {viewColumn: column, preview: false})
+			return window.showTextDocument(doc, { viewColumn: column, preview: false })
 				.then(editor => !!editor);
 		}, () => false)
 		.then(didOpen => {
@@ -1048,7 +1049,7 @@ async function cleanJavaWorkspaceStorage() {
 				}
 			}
 		});
-    }
+	}
 }
 
 function registerOutOfMemoryDetection(storagePath: string) {
@@ -1065,3 +1066,41 @@ function registerOutOfMemoryDetection(storagePath: string) {
 		showOOMMessage();
 	});
 }
+
+function registerRestartJavaLanguageServerCommand(context: ExtensionContext) {
+	context.subscriptions.push(commands.registerCommand(Commands.RESTART_LANGUAGE_SERVER, async () => {
+		// Can be replaced with `await languageClient.restart()` with vscode-languageclient ^8.0.1,
+		switch (getJavaServerMode()) {
+			case (ServerMode.STANDARD):
+				// Standard server restart
+				await standardClient.stop();
+				if (DEBUG) {
+					await new Promise((resolve) => setTimeout(resolve, 2000));
+				}
+				standardClient.start();
+				break;
+			case (ServerMode.LIGHTWEIGHT):
+				// Syntax server restart
+				await syntaxClient.stop();
+				if (DEBUG) {
+					await new Promise((resolve) => setTimeout(resolve, 2000));
+				}
+				syntaxClient.start();
+				break;
+			case (ServerMode.HYBRID):
+				if (syntaxClient.isAlive()) {
+					await syntaxClient.stop();
+					if (DEBUG) {
+						await new Promise((resolve) => setTimeout(resolve, 2000));
+					}
+					syntaxClient.start();
+				}
+				await standardClient.stop();
+				if (DEBUG) {
+					await new Promise((resolve) => setTimeout(resolve, 2000));
+				}
+				standardClient.start();
+				break;
+		}
+	}));
+}

src/javaServerStarter.ts

@@ -13,7 +13,7 @@ import { workspace, ExtensionContext, window } from 'vscode';
 import { addLombokParam, isLombokSupportEnabled } from './lombokSupport';
 
 declare var v8debug;
-const DEBUG = (typeof v8debug === 'object') || startedInDebugMode();
+export const DEBUG = (typeof v8debug === 'object') || startedInDebugMode();
 
 /**
  * Argument that tells the program where to generate the heap dump that is created when an OutOfMemoryError is raised and `HEAP_DUMP` has been passed