| Instrumenting Resources |
| JMX Consoles |
| Tutorials |
The facilities of JMX are a convenient way to provide an administration interface to objects and components in web applications.
| Instrumenting Resources |
Instrumenting resources so JMX can manage them consists of the following steps:
- For a class MyFoo, create an interface MyFooMBean with the management interface.
- Class MyFoo needs to the MyFooMBean interface.
- Register MyFoo with the JMX server.
Instrumenting a servlet
Resin will automatically register any servlet which implement an MBean interface. By default, the JMX name will be:
web-app:j2eeType=Servlet,name=
|
| Attribute | Value |
|---|---|
| j2eeType | Servlet |
| WebModule | the |
| J2EEApplication | the host? |
| J2EEServer | the server-id? |
The domain is , the type property is javax.servlet.Servlet and the name property is the value of <servlet-name>.
JMX clients will use the name to manage the servlet. For example, a client might use the pattern to retrieve all managed servlets.
package test;
public interface MyServletMBean {
public int getCount();
}
|
package test;
import java.io.*;
import javax.servlet.*;
public class MyServlet extends GenericServlet implements MyServletMBean {
private int count;
public int getCount()
{
return count;
}
public void service(ServletRequest request,
ServletResponse response)
throws IOException
{
PrintWriter out = response.getWriter();
count++;
out.println("Hello, world");
}
}
|
| Managing Resources |
Managing resources uses the JMX API, primarily using the MBeanServer object. In Resin, each web-app has its own MBeanServer.
import javax.management.*;
...
MBeanServer server = MBeanServerFactory.createMBeanServer();
ObjectName name = new ObjectName("web-app:j2eeType=javax.servlet.Servlet," +
"name=hello");
Object value = server.getAttribute(name, "Count");
out.println("Count: " + value);
|
/resin-status
The resin-status servlet has a primitive generic JMX management view of JMX managed servlets. By adding a MBean interface to your servlet, you'll automatically get a view of your servlets from /resin-status.
| JMX Consoles |
| Tutorials |
| Copyright © 1998-2006 Caucho Technology, Inc. All rights reserved. Resin® is a registered trademark, and HardCoretm and Quercustm are trademarks of Caucho Technology, Inc. |  |