--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/demo/management/JTop/JTopPlugin.java	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,119 @@
+/*
+ * Copyright 2006 Sun Microsystems, Inc.  All Rights Reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ *   - Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *
+ *   - 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.
+ *
+ *   - Neither the name of Sun Microsystems nor the names of its
+ *     contributors may be used to endorse or promote products derived
+ *     from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
+ * IS" AND ANY EXPRESS 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 COPYRIGHT OWNER OR
+ * 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.
+ */
+
+/*
+ *
+ * Example of a JConsole Plugin.  This loads JTop as a JConsole tab.
+ *
+ * @author Mandy Chung
+ */
+
+import java.beans.PropertyChangeEvent;
+import java.beans.PropertyChangeListener;
+import java.util.LinkedHashMap;
+import java.util.Map;
+import javax.management.MBeanServerConnection;
+import javax.swing.JPanel;
+import javax.swing.SwingWorker;
+
+import com.sun.tools.jconsole.JConsolePlugin;
+import com.sun.tools.jconsole.JConsoleContext;
+import com.sun.tools.jconsole.JConsoleContext.ConnectionState;
+
+/**
+ * JTopPlugin is a subclass to com.sun.tools.jconsole.JConsolePlugin
+ *
+ * JTopPlugin is loaded and instantiated by JConsole.  One instance
+ * is created for each window that JConsole creates. It listens to
+ * the connected property change so that it will update JTop with
+ * the valid MBeanServerConnection object.  JTop is a JPanel object
+ * displaying the thread and its CPU usage information.
+ */
+public class JTopPlugin extends JConsolePlugin implements PropertyChangeListener
+{
+    private JTop jtop = null;
+    private Map<String, JPanel> tabs = null;
+
+    public JTopPlugin() {
+        // register itself as a listener
+        addContextPropertyChangeListener(this);
+    }
+
+    /*
+     * Returns a JTop tab to be added in JConsole.
+     */
+    public synchronized Map<String, JPanel> getTabs() {
+        if (tabs == null) {
+            jtop = new JTop();
+            jtop.setMBeanServerConnection(
+                getContext().getMBeanServerConnection());
+            // use LinkedHashMap if you want a predictable order
+            // of the tabs to be added in JConsole
+            tabs = new LinkedHashMap<String, JPanel>();
+            tabs.put("JTop", jtop);
+        }
+        return tabs;
+    }
+
+    /*
+     * Returns a SwingWorker which is responsible for updating the JTop tab.
+     */
+    public SwingWorker<?,?> newSwingWorker() {
+        return jtop.newSwingWorker();
+    }
+
+    // You can implement the dispose() method if you need to release
+    // any resource when the plugin instance is disposed when the JConsole
+    // window is closed.
+    //
+    // public void dispose() {
+    // }
+
+    /*
+     * Property listener to reset the MBeanServerConnection
+     * at reconnection time.
+     */
+    public void propertyChange(PropertyChangeEvent ev) {
+        String prop = ev.getPropertyName();
+        if (prop == JConsoleContext.CONNECTION_STATE_PROPERTY) {
+            ConnectionState oldState = (ConnectionState)ev.getOldValue();
+            ConnectionState newState = (ConnectionState)ev.getNewValue();
+            // JConsole supports disconnection and reconnection
+            // The MBeanServerConnection will become invalid when
+            // disconnected. Need to use the new MBeanServerConnection object
+            // created at reconnection time.
+            if (newState == ConnectionState.CONNECTED && jtop != null) {
+                jtop.setMBeanServerConnection(
+                    getContext().getMBeanServerConnection());
+            }
+        }
+    }
+}