1 /*
2  * Copyright (c) 2006, 2011, Oracle and/or its affiliates. All rights reserved.
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  *
8  *   - Redistributions of source code must retain the above copyright
9  *     notice, this list of conditions and the following disclaimer.
10  *
11  *   - Redistributions in binary form must reproduce the above copyright
12  *     notice, this list of conditions and the following disclaimer in the
13  *     documentation and/or other materials provided with the distribution.
14  *
15  *   - Neither the name of Oracle nor the names of its
16  *     contributors may be used to endorse or promote products derived
17  *     from this software without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
20  * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
21  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
23  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
24  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
25  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
26  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
27  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
28  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
29  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 /*
33  * This source code is provided to illustrate the usage of a given feature
34  * or technique and has been deliberately simplified. Additional steps
35  * required for a production-quality application, such as security checks,
36  * input validation and proper error handling, might not be present in
37  * this sample code.
38  */
39 
40 
41 /*
42  *
43  * Example of a JConsole Plugin.  This loads JTop as a JConsole tab.
44  *
45  * @author Mandy Chung
46  */
47 
48 import java.beans.PropertyChangeEvent;
49 import java.beans.PropertyChangeListener;
50 import java.util.LinkedHashMap;
51 import java.util.Map;
52 
53 import javax.swing.JPanel;
54 import javax.swing.SwingWorker;
55 
56 import com.sun.tools.jconsole.JConsoleContext;
57 import com.sun.tools.jconsole.JConsoleContext.ConnectionState;
58 import com.sun.tools.jconsole.JConsolePlugin;
59 
60 /**
61  * JTopPlugin is a subclass to com.sun.tools.jconsole.JConsolePlugin
62  *
63  * JTopPlugin is loaded and instantiated by JConsole.  One instance
64  * is created for each window that JConsole creates. It listens to
65  * the connected property change so that it will update JTop with
66  * the valid MBeanServerConnection object.  JTop is a JPanel object
67  * displaying the thread and its CPU usage information.
68  */
69 public class JTopPlugin extends JConsolePlugin implements PropertyChangeListener
70 {
71     private JTop jtop = null;
72     private Map<String, JPanel> tabs = null;
73 
JTopPlugin()74     public JTopPlugin() {
75         // register itself as a listener
76         addContextPropertyChangeListener(this);
77     }
78 
79     /*
80      * Returns a JTop tab to be added in JConsole.
81      */
82     @Override
getTabs()83     public synchronized Map<String, JPanel> getTabs() {
84         if (tabs == null) {
85             jtop = new JTop();
86             jtop.setMBeanServerConnection(
87                 getContext().getMBeanServerConnection());
88             // use LinkedHashMap if you want a predictable order
89             // of the tabs to be added in JConsole
90             tabs = new LinkedHashMap<String, JPanel>();
91             tabs.put("JTop", jtop);
92         }
93         return tabs;
94     }
95 
96     /*
97      * Returns a SwingWorker which is responsible for updating the JTop tab.
98      */
99     @Override
newSwingWorker()100     public SwingWorker<?,?> newSwingWorker() {
101         return jtop.newSwingWorker();
102     }
103 
104     // You can implement the dispose() method if you need to release
105     // any resource when the plugin instance is disposed when the JConsole
106     // window is closed.
107     //
108     // public void dispose() {
109     // }
110 
111     /*
112      * Property listener to reset the MBeanServerConnection
113      * at reconnection time.
114      */
115     @Override
propertyChange(PropertyChangeEvent ev)116     public void propertyChange(PropertyChangeEvent ev) {
117         String prop = ev.getPropertyName();
118         if (prop == JConsoleContext.CONNECTION_STATE_PROPERTY) {
119             ConnectionState newState = (ConnectionState)ev.getNewValue();
120             // JConsole supports disconnection and reconnection
121             // The MBeanServerConnection will become invalid when
122             // disconnected. Need to use the new MBeanServerConnection object
123             // created at reconnection time.
124             if (newState == ConnectionState.CONNECTED && jtop != null) {
125                 jtop.setMBeanServerConnection(
126                     getContext().getMBeanServerConnection());
127             }
128         }
129     }
130 }
131