diff --git a/src/main/org/apache/tools/ant/taskdefs/optional/extension/JarLibDisplayTask.java b/src/main/org/apache/tools/ant/taskdefs/optional/extension/JarLibDisplayTask.java
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index 000000000..be5382b59
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+++ b/src/main/org/apache/tools/ant/taskdefs/optional/extension/JarLibDisplayTask.java
@@ -0,0 +1,165 @@
+/*
+ * The Apache Software License, Version 1.1
+ *
+ * Copyright (c) 2002 The Apache Software Foundation.  All rights
+ * reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * 3. The end-user documentation included with the redistribution, if
+ *    any, must include the following acknowlegement:
+ *       "This product includes software developed by the
+ *        Apache Software Foundation (http://www.apache.org/)."
+ *    Alternately, this acknowlegement may appear in the software itself,
+ *    if and wherever such third-party acknowlegements normally appear.
+ *
+ * 4. The names "The Jakarta Project", "Ant", and "Apache Software
+ *    Foundation" must not be used to endorse or promote products derived
+ *    from this software without prior written permission. For written
+ *    permission, please contact apache@apache.org.
+ *
+ * 5. Products derived from this software may not be called "Apache"
+ *    nor may "Apache" appear in their names without prior written
+ *    permission of the Apache Group.
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
+ * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+ * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ * ====================================================================
+ *
+ * This software consists of voluntary contributions made by many
+ * individuals on behalf of the Apache Software Foundation.  For more
+ * information on the Apache Software Foundation, please see
+ * <http://www.apache.org/>.
+ */
+package org.apache.tools.ant.taskdefs.optional.extension;
+
+import java.io.File;
+import java.util.Iterator;
+import java.util.Vector;
+import org.apache.tools.ant.BuildException;
+import org.apache.tools.ant.DirectoryScanner;
+import org.apache.tools.ant.Task;
+import org.apache.tools.ant.types.FileSet;
+
+/**
+ * Display the "Optional Package" and "Package Specification" information
+ * contained within the specified jars.
+ *
+ * <p>Prior to JDK1.3, an "Optional Package" was known as an Extension.
+ * The specification for this mechanism is available in the JDK1.3
+ * documentation in the directory
+ * $JDK_HOME/docs/guide/extensions/versioning.html. Alternatively it is
+ * available online at <a href="http://java.sun.com/j2se/1.3/docs/guide/extensions/versioning.html">
+ * http://java.sun.com/j2se/1.3/docs/guide/extensions/versioning.html</a>.</p>
+ *
+ * @author <a href="mailto:peter@apache.org">Peter Donald</a>
+ * @ant.task name="jarlib-display"
+ */
+public class JarLibDisplayTask
+    extends Task
+{
+    /**
+     * The library to display information about.
+     */
+    private File m_file;
+
+    /**
+     * Filesets specifying all the librarys
+     * to display information about.
+     */
+    private final Vector m_filesets = new Vector();
+
+    /**
+     * The jar library to display information for.
+     *
+     * @param file The jar library to display information for.
+     */
+    public void setFile( final File file )
+    {
+        m_file = file;
+    }
+
+    /**
+     * Adds a set of files about which library data will be displayed.
+     *
+     * @param fileSet a set of files about which library data will be displayed.
+     */
+    public void addFileset( final FileSet fileSet )
+    {
+        m_filesets.addElement( fileSet );
+    }
+
+    public void execute()
+        throws BuildException
+    {
+        validate();
+
+        final LibraryDisplayer displayer = new LibraryDisplayer();
+        // Check if list of files to check has been specified
+        if( !m_filesets.isEmpty() )
+        {
+            final Iterator iterator = m_filesets.iterator();
+            while( iterator.hasNext() )
+            {
+                final FileSet fileSet = (FileSet)iterator.next();
+                final DirectoryScanner scanner = fileSet.getDirectoryScanner( getProject() );
+                final File basedir = scanner.getBasedir();
+                final String[] files = scanner.getIncludedFiles();
+                for( int i = 0; i < files.length; i++ )
+                {
+                    final File file = new File( basedir, files[ i ] );
+                    displayer.displayLibrary( file );
+                }
+            }
+        }
+        else
+        {
+            displayer.displayLibrary( m_file );
+        }
+    }
+
+    /**
+     * Validate the tasks parameters.
+     *
+     * @throws BuildException if invalid parameters found
+     */
+    private void validate()
+        throws BuildException
+    {
+        if( null == m_file && m_filesets.isEmpty() )
+        {
+            final String message = "File attribute not specified.";
+            throw new BuildException( message );
+        }
+        if( null != m_file && !m_file.exists() )
+        {
+            final String message = "File '" + m_file + "' does not exist.";
+            throw new BuildException( message );
+        }
+        if( null != m_file && !m_file.isFile() )
+        {
+            final String message = "\'" + m_file + "\' is not a file.";
+            throw new BuildException( message );
+        }
+    }
+}