<html><head><META http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"><title>Jython MBean</title><link href="styles.css" type="text/css" rel="stylesheet"><meta content="DocBook XSL Stylesheets V1.78.1" name="generator"><link rel="home" href="index.html" title="MX4J English Documentation"><link rel="up" href="ch06.html" title="Chapter 6. MX4J Tools"><link rel="prev" href="ch06s04.html" title="Mailer MBean"><link rel="next" href="ch07.html" title="Chapter 7. MX4J Examples"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table summary="Navigation header" width="100%"><tr><th align="center" colspan="3">Jython MBean</th></tr><tr><td align="left" width="20%"><a accesskey="p" href="ch06s04.html">Prev</a> </td><th align="center" width="60%">Chapter 6. MX4J Tools</th><td align="right" width="20%"> <a accesskey="n" href="ch07.html">Next</a></td></tr></table><hr></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="N10DDB"></a>Jython MBean</h2></div></div></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="N10DDE"></a>Introduction</h3></div></div></div><p>
The JythonRunner MBean can be used to execute jython scripts. The main objective is
to use them for management tasks which are easiliy handled as scripts and that could be
modified and deployed at runtime.
The MBean's class is
<code class="classname">mx4j.tools.jython.JythonRunner</code>.
</p><p>
You can use it in two ways:
</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p>
By calling the runScript method
</p></li><li class="listitem"><p>
By listening notifications, for instance from a Timer or Monitor
</p></li></ul></div><p>
</p><p>
The usage of the MBean requires that you have jython installed. You can get a copy
at
<a class="ulink" href="http://www.jython.org" target="_top">http://www.jython.org</a>. Jython is distributed
(as version 2.1) on a class file which is the installer and once execute will install the
jython distribution, e.g. at /usr/local/jython-2.1 or C:\Java\jython-2.1. Jython can be run in
two different ways depending on whether you want to use the jython standard library.
</p><p>If you want to use the standard librarie, add the jython.jar as in the installation dir to the classpath. e.g.
</p><p>java -cp /usr/local/jython-2.1/jython.jar:mx4j-jmx.jar:mx4j-tools.jar</p><p>
In this way jython will be able to find the install dir and load the libraries from there. You can get the same effect by
passing a python.path variable as:
</p><p>java -Dpython.path=/usr/local/jython-2.1 -cp jython.jar:mx4j-jmx.jar:mx4j-tools.jar</p><p>
</p><p>
</p><p>If you don't need the standard libraries (and that can be the case for many JMX tasks, it is enough to have the jython.jar
in your system classpath</p><p>
</p></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="N10E02"></a>Configuration</h3></div></div></div><p>
The MBean has a few parameters which can be used to configure the MBean. This includes the
ObservedObjectName and Notification Name used to configure the MBean to listen for notifications.
The Script and ScriptFile parameters point to the content of the script. For simple scripts
you could just use the Script parameter. For morke comple scripts you are better of pointing to a file.
The ScriptFile is actually a URL and therefore can point to http locations
</p></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="N10E07"></a>Built-in functions</h3></div></div></div><p>
To ease the script constructions some variables, class and functions are readily
available to your script. The most important one is
<span class="emphasis"><em>server</em></span> which point
to the current MBean server. The server variable IS a MBeanServer object and all methods
are valid. You can write scripts like:
</p><pre class="programlisting">
# write all the "test:name=test" mbean operations
[print operation for operation in server.getMBeanInfo(ObjectName("test:name=test")).operations]
</pre><p>
Aditionally all the javax.management.* class are imported making objects like ObjectName
or Attribute already available.
</p><p>
There are also some utility functions and classes:
</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p>
<code class="classname">proxy</code> The proxy class wraps a objectname making it easier
to access (It is equivalent to the MBeanServerInvocationHandler class). You can directly retrieve and modify attributes and invoke mathods. For instance:
</p><pre class="programlisting">
#
# Assume the MBean with ObjectName Test:name=jython has name and time attributes and a method start()
#
o = ObjectName("Test:name=jython")
p = proxy(o)
# you can access functions directly
print p.name
p.time = 12343
# also works with functions
p.start()
</pre><p>
</p></li><li class="listitem"><p>
<code class="function">mbeans(query)</code> Returns a list of the mbeans in the server which
are in the query. The query is of the form "*:*". It can be omited and the function will
return all the mbeans
</p></li><li class="listitem"><p>
<code class="function">instances(classname, query)</code> Returns a list of the mbeans in the server which
are instances of classname. The server accepts also an optional query method.
</p></li></ul></div><p>
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