Rework CoreUtility.deleteContent() for Java 25 compatibility and symlink safety

ui/org.eclipse.pde.core/src/org/eclipse/pde/internal/core/util/CoreUtility.java

@@ -34,7 +34,6 @@
 import org.eclipse.core.runtime.IPath;
 import org.eclipse.core.runtime.IProgressMonitor;
 import org.eclipse.core.runtime.Platform;
-import org.eclipse.core.runtime.SubMonitor;
 import org.eclipse.pde.internal.core.PDECore;
 
 public class CoreUtility {
@@ -125,26 +124,7 @@ public static void deleteContent(File fileToDelete) {
 	 * @param monitor progress monitor for reporting and cancellation, can be <code>null</code>
 	 */
 	public static void deleteContent(File fileToDelete, IProgressMonitor monitor) {
-		// can be symlinks
-		if (!fileToDelete.exists()) {
-			fileToDelete.delete();
-		}
-		if (fileToDelete.exists()) {
-			SubMonitor subMon = SubMonitor.convert(monitor, 100);
-
-			if (fileToDelete.isDirectory()) {
-				File[] children = fileToDelete.listFiles();
-				if (children != null && children.length > 0) {
-					SubMonitor childMon = SubMonitor.convert(subMon.split(90), children.length);
-					for (File element : children) {
-						deleteContent(element, childMon.split(1));
-					}
-				}
-			}
-			fileToDelete.delete();
-
-			subMon.done();
-		}
+		DeleteContentWalker.deleteDirectory(fileToDelete.toPath(), monitor);
 	}
 
 	public static boolean jarContainsResource(File file, String resource, boolean directory) {

ui/org.eclipse.pde.core/src/org/eclipse/pde/internal/core/util/DeleteContentWalker.java

@@ -0,0 +1,135 @@
+/*******************************************************************************
+ * Copyright (c) 2025 Dieter Mai and others.
+ *
+ * This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License 2.0
+ * which accompanies this distribution, and is available at
+ * https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ *     Dieter Mai - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.pde.internal.core.util;
+
+import java.io.IOException;
+import java.nio.file.FileVisitResult;
+import java.nio.file.FileVisitor;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.attribute.BasicFileAttributes;
+import java.util.Objects;
+
+import org.eclipse.core.runtime.IProgressMonitor;
+import org.eclipse.core.runtime.NullProgressMonitor;
+import org.eclipse.core.runtime.Platform;
+import org.eclipse.core.runtime.SubMonitor;
+
+/**
+ * Deletes content of a directory recursively.
+ */
+public class DeleteContentWalker implements FileVisitor<Path> {
+
+	/**
+	 * Deletes the given root directory and its content. If the deletion fails
+	 * or is canceled by the user, the method returns silently.
+	 *
+	 * @param root
+	 *            The root directory to delete.
+	 * @param monitor
+	 *            The monitor to report progress to. Can be null.
+	 */
+	public static void deleteDirectory(Path root, IProgressMonitor monitor) {
+		// if there is no file, no need to proceed
+		if (root == null || !Files.exists(root)) {
+			return;
+		}
+
+		IProgressMonitor submonitor = createSubMonitor(root, monitor);
+
+		try {
+			Files.walkFileTree(root, new DeleteContentWalker(root, submonitor));
+		} catch (IOException e) {
+			// noting to do
+		} finally {
+			submonitor.done();
+		}
+	}
+
+	private static IProgressMonitor createSubMonitor(Path root, IProgressMonitor monitor) {
+		IProgressMonitor submonitor;
+		if (monitor == null || monitor instanceof NullProgressMonitor) {
+			submonitor = SubMonitor.convert(monitor);
+		} else {
+			try (var stream = Files.list(root)) {
+				// only use the root content for progress. anything else would
+				// be overkill.
+				long count = stream.count();
+				submonitor = SubMonitor.convert(monitor, (int) count);
+			} catch (IOException e) {
+				// In case of error, just ignore the monitor;
+				submonitor = SubMonitor.convert(monitor);
+			}
+		}
+		return submonitor;
+	}
+
+	private final Path root;
+	private final IProgressMonitor monitor;
+
+	private DeleteContentWalker(Path root, IProgressMonitor monitor) {
+		this.root = root;
+		this.monitor = monitor;
+	}
+
+	@Override
+	public FileVisitResult preVisitDirectory(Path path, BasicFileAttributes attrs) throws IOException {
+		if (Platform.OS.isWindows()) {
+			Files.setAttribute(path, "dos:readonly", false); //$NON-NLS-1$
+		}
+		return resultIfNotCanceled(FileVisitResult.CONTINUE);
+	}
+
+	@Override
+	public FileVisitResult visitFile(Path path, BasicFileAttributes attrs) throws IOException {
+		if (Platform.OS.isWindows()) {
+			Files.setAttribute(path, "dos:readonly", false); //$NON-NLS-1$
+		}
+		Files.deleteIfExists(path);
+
+		if (Objects.equals(path.getParent(), root)) {
+			monitor.worked(1);
+		}
+		return resultIfNotCanceled(FileVisitResult.CONTINUE);
+	}
+
+	@Override
+	public FileVisitResult visitFileFailed(Path file, IOException exc) throws IOException {
+		if (exc != null) {
+			throw exc;
+		}
+		return resultIfNotCanceled(FileVisitResult.CONTINUE);
+	}
+
+	@Override
+	public FileVisitResult postVisitDirectory(Path path, IOException exc) throws IOException {
+		Files.deleteIfExists(path);
+
+		if (Objects.equals(path.getParent(), root)) {
+			monitor.worked(1);
+		}
+		return resultIfNotCanceled(FileVisitResult.CONTINUE);
+	}
+
+	/**
+	 * Returns the given result if not canceled. If canceled
+	 * {@link FileVisitResult#TERMINATE} is returned.
+	 */
+	private FileVisitResult resultIfNotCanceled(FileVisitResult result) {
+		if (monitor.isCanceled()) {
+			return FileVisitResult.TERMINATE;
+		}
+		return result;
+	}
+}