--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/make/langtools/tools/anttasks/DumpClassesTask.java	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,81 @@
+/*
+ * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package anttasks;
+
+import java.io.File;
+import java.io.IOException;
+import java.io.UncheckedIOException;
+import java.net.URI;
+import java.net.URISyntaxException;
+import java.nio.file.FileSystem;
+import java.nio.file.FileSystems;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.StandardCopyOption;
+import java.util.Collections;
+import java.util.stream.Stream;
+
+import org.apache.tools.ant.BuildException;
+import org.apache.tools.ant.Task;
+
+public class DumpClassesTask extends Task {
+
+    private String moduleName;
+    private File dir;
+
+    public void setModuleName(String moduleName) {
+        this.moduleName = moduleName;
+    }
+
+    public void setDestDir(File dir) {
+        this.dir = dir;
+    }
+
+    @Override
+    public void execute() {
+        try (FileSystem fs = FileSystems.newFileSystem(new URI("jrt:/"), Collections.emptyMap(), DumpClassesTask.class.getClassLoader())) {
+            Path source = fs.getPath("modules", moduleName);
+            Path target = dir.toPath();
+
+            try (Stream<Path> content = Files.walk(source)) {
+                content.filter(Files :: isRegularFile)
+                       .forEach(p -> {
+                    try {
+                        Path targetFile = target.resolve(source.relativize(p).toString());
+                        if (!Files.exists(targetFile) || Files.getLastModifiedTime(targetFile).compareTo(Files.getLastModifiedTime(source)) < 0) {
+                            Files.createDirectories(targetFile.getParent());
+                            Files.copy(p, targetFile, StandardCopyOption.REPLACE_EXISTING);
+                        }
+                    } catch (IOException ex) {
+                        throw new UncheckedIOException(ex);
+                    }
+                });
+            }
+        } catch (URISyntaxException | IOException | UncheckedIOException ex) {
+            throw new BuildException(ex);
+        }
+    }
+}