title: How to solve "javax.management.InstanceNotFoundException" when accessing JBoss 5.1.0.GA 's mbeans?
body: <p>I have the following error when accessing JBoss 5.1.0.GA's mebeans.</p>
  
  <pre><code>     Exception in thread "main" javax.management.InstanceNotFoundException: jboss.system:type=ServerInfo
  at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.getMBean(DefaultMBeanServerInterceptor.java:1094)
  at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.getAttribute(DefaultMBeanServerInterceptor.java:662)
  at com.sun.jmx.mbeanserver.JmxMBeanServer.getAttribute(JmxMBeanServer.java:638)
  at javax.management.remote.rmi.RMIConnectionImpl.doOperation(RMIConnectionImpl.java:1404)
  at javax.management.remote.rmi.RMIConnectionImpl.access$200(RMIConnectionImpl.java:72)
  at javax.management.remote.rmi.RMIConnectionImpl$PrivilegedOperation.run(RMIConnectionImpl.java:1265)
  at javax.management.remote.rmi.RMIConnectionImpl.doPrivilegedOperation(RMIConnectionImpl.java:1360)
  at javax.management.remote.rmi.RMIConnectionImpl.getAttribute(RMIConnectionImpl.java:600)
  at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
  at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
  at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
  at java.lang.reflect.Method.invoke(Method.java:597)
  at sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:305)
  at sun.rmi.transport.Transport$1.run(Transport.java:159)
  at java.security.AccessController.doPrivileged(Native Method)
  at sun.rmi.transport.Transport.serviceCall(Transport.java:155)
  at sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:535)
  at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(TCPTransport.java:790)
  at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:649)
  at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
  at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
  at java.lang.Thread.run(Thread.java:662)
  at sun.rmi.transport.StreamRemoteCall.exceptionReceivedFromServer(StreamRemoteCall.java:255)
  at sun.rmi.transport.StreamRemoteCall.executeCall(StreamRemoteCall.java:233)
  at sun.rmi.server.UnicastRef.invoke(UnicastRef.java:142)
  at com.sun.jmx.remote.internal.PRef.invoke(Unknown Source)
  at javax.management.remote.rmi.RMIConnectionImpl_Stub.getAttribute(Unknown Source)
  at javax.management.remote.rmi.RMIConnector$RemoteMBeanServerConnection.getAttribute(RMIConnector.java:878)
  at test.mbean.JBossJMXClient.main(JBossJMXClient.java:30)
  </code></pre>
  
  <p>Here is my java class;</p>
  
  <pre><code>public class JBossJMXClient {
      public static void main(String[] args) throws Exception {
          String host = "192.168.0.249";// Your JBoss Bind Address default is
                                      // localhost
      int port = 4545; // management-native port
          String urlString = "service:jmx:rmi:///jndi/rmi://" + host + ":" + port
              + "/jmxrmi";
          System.out.println("        \n\n\t****  urlString: " + urlString);
      JMXServiceURL serviceURL = new JMXServiceURL(urlString);
      JMXConnector jmxConnector = JMXConnectorFactory.connect(serviceURL,
              null);
      MBeanServerConnection connection = jmxConnector
              .getMBeanServerConnection();
  
      // Invoke on the JBoss AS MBean server
      int count = connection.getMBeanCount();
      System.out.println(count);
      ObjectName objectName = new ObjectName("jboss.system:type=ServerInfo");
      String javaVersion = (String)connection.getAttribute(objectName, "JavaVersion");
      System.out.println(javaVersion);
      jmxConnector.close();
       }
    }
  </code></pre>
  
  <p>I already ckecked firewall.It has no problem.How to solve this issue?</p>