Prompt user when switching to a locked workspace in Eclipse

Prompts user on attempting to switch to a workspace that is currently
locked by another Eclipse instance, a prompt dialog is now shown
informing the user about the lock details and preventing Eclipse from
exiting

Author: SougandhS

bundles/org.eclipse.e4.ui.workbench.swt/src/org/eclipse/e4/ui/workbench/swt/internal/copy/WorkbenchSWTMessages.java

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2005, 2019 IBM Corporation and others.
+ * Copyright (c) 2005, 2025 IBM Corporation and others.
  *
  * This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License 2.0
@@ -42,6 +42,17 @@ public class WorkbenchSWTMessages extends NLS {
 	public static String InternalError;
 	public static String IDEApplication_versionTitle;
 	public static String IDEApplication_versionMessage;
+	public static String IDEApplication_workspaceLockMessage;
+
+	public static String IDEApplication_workspaceLockOwner;
+
+	public static String IDEApplication_workspaceLockHost;
+
+	public static String IDEApplication_workspaceLockDisplay;
+
+	public static String IDEApplication_workspaceLockPID;
+
+	public static String IDEApplication_workspaceCannotLockMessage2;
 
 	static {
 		// load message values from bundle file

bundles/org.eclipse.e4.ui.workbench.swt/src/org/eclipse/e4/ui/workbench/swt/internal/copy/messages.properties

@@ -1,5 +1,5 @@
 ###############################################################################
-# Copyright (c) 2000, 2019 IBM Corporation and others.
+# Copyright (c) 2000, 2025 IBM Corporation and others.
 #
 # This program and the accompanying materials
 # are made available under the terms of the Eclipse Public License 2.0
@@ -42,3 +42,9 @@ This workspace was written with a different version of the product and needs to
 {0}\n\n\
 Updating the workspace may make it incompatible with other versions of the product.\n\
 Press OK to update the workspace and open it. Press Cancel to select a different workspace.
+IDEApplication_workspaceLockOwner=User:\t\t{0}\n
+IDEApplication_workspaceLockHost=Host:\t\t{0}\n
+IDEApplication_workspaceLockDisplay=Display:\t\t{0}\n
+IDEApplication_workspaceLockPID=Process ID:\t{0}\n
+IDEApplication_workspaceLockMessage=Workspace lock is currently held by:\n{0}
+IDEApplication_workspaceCannotLockMessage2=Could not switch to the selected workspace ''{0}'' because it is currently in use by another Eclipse instance.

bundles/org.eclipse.ui.workbench/eclipseui/org/eclipse/ui/internal/Workbench.java

@@ -35,9 +35,12 @@
 import java.io.InputStream;
 import java.io.StringReader;
 import java.io.StringWriter;
+import java.net.MalformedURLException;
 import java.net.URI;
 import java.net.URISyntaxException;
 import java.net.URL;
+import java.nio.file.Files;
+import java.nio.file.Path;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
@@ -49,6 +52,7 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;
+import java.util.Properties;
 import java.util.Set;
 import java.util.UUID;
 import java.util.concurrent.atomic.AtomicReference;
@@ -80,6 +84,7 @@
 import org.eclipse.core.runtime.SafeRunner;
 import org.eclipse.core.runtime.Status;
 import org.eclipse.core.runtime.SubMonitor;
+import org.eclipse.core.runtime.URIUtil;
 import org.eclipse.core.runtime.dynamichelpers.IExtensionTracker;
 import org.eclipse.core.runtime.jobs.Job;
 import org.eclipse.core.runtime.preferences.ConfigurationScope;
@@ -114,6 +119,7 @@
 import org.eclipse.e4.ui.workbench.modeling.EModelService;
 import org.eclipse.e4.ui.workbench.modeling.EPartService;
 import org.eclipse.e4.ui.workbench.modeling.ISaveHandler;
+import org.eclipse.e4.ui.workbench.swt.internal.copy.WorkbenchSWTMessages;
 import org.eclipse.emf.ecore.EObject;
 import org.eclipse.emf.ecore.resource.Resource;
 import org.eclipse.emf.ecore.util.EcoreUtil;
@@ -2699,7 +2705,8 @@ private static String buildCommandLine(String workspace) {
 	 * as the workspace location.
 	 *
 	 * @param workspacePath the new workspace location
-	 * @return {@link IApplication#EXIT_OK} or {@link IApplication#EXIT_RELAUNCH}
+	 * @return {@link IApplication#EXIT_OK} or {@link IApplication#EXIT_RELAUNCH} or
+	 *         <code>null</code>
 	 */
 	@SuppressWarnings("restriction")
 	public static Object setRestartArguments(String workspacePath) {
@@ -2714,12 +2721,88 @@ public static Object setRestartArguments(String workspacePath) {
 		if (command_line == null) {
 			return IApplication.EXIT_OK;
 		}
+		Path selectedWorkspace = Path.of(workspacePath);
+		try {
+			String workspaceLock = getWorkspaceLockDetails(selectedWorkspace.toUri().toURL());
+			if (workspaceLock != null && !workspaceLock.isEmpty()) {
+				String lockMessage = NLS.bind(WorkbenchSWTMessages.IDEApplication_workspaceCannotLockMessage2,
+						workspacePath);
+				String wsLockedError = lockMessage + System.lineSeparator() + System.lineSeparator()
+						+ NLS.bind(WorkbenchSWTMessages.IDEApplication_workspaceLockMessage,
+						workspaceLock);
+
+				MessageDialog.openError(PlatformUI.getWorkbench().getActiveWorkbenchWindow().getShell(),
+						WorkbenchSWTMessages.IDEApplication_workspaceCannotLockTitle,
+						wsLockedError);
+				return null;
+			}
+		} catch (MalformedURLException e) {
+			return null;
+		}
 
 		System.setProperty(Workbench.PROP_EXIT_CODE, IApplication.EXIT_RELAUNCH.toString());
 		System.setProperty(IApplicationContext.EXIT_DATA_PROPERTY, command_line);
 		return IApplication.EXIT_RELAUNCH;
 	}
 
+	/**
+	 * Extract the lock details of the selected workspace if it is locked by another
+	 * Eclipse application
+	 *
+	 * @param workspaceUrl the <code>URL</code> of selected workspace
+	 * @return <code>String</code> details of lock owned workspace,
+	 *         <code>null or Empty</code> if not locked
+	 */
+	@SuppressWarnings("restriction")
+	private static String getWorkspaceLockDetails(URL workspaceUrl) {
+		Path lockFile = getLockInfoFile(workspaceUrl);
+		if (lockFile != null && Files.exists(lockFile)) {
+			StringBuilder lockDetails = new StringBuilder();
+			Properties properties = new Properties();
+			try (InputStream is = Files.newInputStream(lockFile)) {
+				properties.load(is);
+				String prop = properties.getProperty("user"); //$NON-NLS-1$
+				if (prop != null) {
+					lockDetails.append(NLS.bind(WorkbenchSWTMessages.IDEApplication_workspaceLockOwner, prop));
+				}
+				prop = properties.getProperty("host"); //$NON-NLS-1$
+				if (prop != null) {
+					lockDetails.append(NLS.bind(WorkbenchSWTMessages.IDEApplication_workspaceLockHost, prop));
+				}
+				prop = properties.getProperty("display"); //$NON-NLS-1$
+				if (prop != null) {
+					lockDetails.append(NLS.bind(WorkbenchSWTMessages.IDEApplication_workspaceLockDisplay, prop));
+				}
+				prop = properties.getProperty("process-id"); //$NON-NLS-1$
+				if (prop != null) {
+					lockDetails.append(NLS.bind(WorkbenchSWTMessages.IDEApplication_workspaceLockPID, prop));
+				}
+
+			} catch (IOException e) {
+				WorkbenchPlugin.log(e);
+			}
+			return lockDetails.toString();
+		}
+		return null;
+	}
+
+	/**
+	 * Returns the lock file.
+	 *
+	 * @param workspaceUrl the <code>URL</code> of selected workspace
+	 * @return the path to the <code>.lock_info</code> file within the specified
+	 *         workspace, or <code> null</code> if the workspace URL cannot be
+	 *         converted to a valid URI
+	 */
+	private static Path getLockInfoFile(URL workspaceUrl) {
+		Path lockFile = Path.of(".metadata", ".lock_info"); //$NON-NLS-1$ //$NON-NLS-2$
+		try {
+			return Path.of(URIUtil.toURI(workspaceUrl)).resolve(lockFile);
+		} catch (URISyntaxException e) {
+			return null;
+		}
+	}
+
 	/**
 	 * Returns the ids of all plug-ins that extend the
 	 * <code>org.eclipse.ui.startup</code> extension point.