[kjkoster]

Dear All,

The question of programatically restarting a Tomcat connector came up twice on the Tomcat mailing lists, in recent weeks. I guess that that is a feature that is really wanted.

I sat down and wrote a little JSP page that does precisely that. I hope you find the code useful. Please feel free to comment on it and correct me.

To make this work, open a file named (for example) reset-connector.jsp in one of your webapps and paste the code below into it.

Kees Jan

<!--
  A small piece of code to programatically reset a Tomcat connector using JMX.

  Written by Kees Jan Koster and published on Java-monitor.com/forum
-->

<jsp:directive.page import="java.util.*" />
<jsp:directive.page import="javax.management.*" />

<%
  // Here, we specify the JMX object name of the connector you'd like to reset.
  // Think of the object name not as a human name (Alice, Bob), but as a query.
  // You can find this object name using jconsole. We used a bunch of wildcards,
  // so that this code will work in any of Tomcat, JBoss and SpringSource dm
  // Server or any of the may other projects that have Tomcat embedded.
  
  // In prose, this object name is something like "any mbean that was registered
  // to have type 'Connector' and port number 8080, but can have more attributes
  // that we don't really care about at this point".
  final ObjectName objectNameQuery = new ObjectName("*:type=Connector,port=8080,*");

  // We now have to find the right MBean server. A running VM typically contains
  // two or so MBean servers. We just root through all of them, to see which one
  // has an MBean matching our query. We also get the precise object name for
  // the connector MBean. We will need that precise name later.
  MBeanServer mbeanServer = null;
  ObjectName objectName = null;
  for (final MBeanServer server : (List<MBeanServer>) MBeanServerFactory.findMBeanServer(null)) {
      if (server.queryNames(objectNameQuery, null).size() > 0) {
          mbeanServer = server;
          objectName = (ObjectName) server.queryNames(objectNameQuery, null).toArray()[0];
          
          // we found it, bail out
          break;
      }
  }

  // now we restart the connector that we just found. We sleep a little, but I am
  // not actually sure 1) how long we should sleep for or 2) if sleeping is
  // necessary at all.
  mbeanServer.invoke(objectName, "stop", null, null);
  Thread.sleep(20000);
  mbeanServer.invoke(objectName, "start", null, null);
  
  // while it is restarting, consider the security implications of this code... :-)
%>