最近發現環境出現ActiveMQ經常掛，報錯的內存溢出，原因差不多應該是隊列裏面的消費放的太多，內存設置的比較小，因爲這個ActiveMQ只是輔助系統運行的，所以也沒怎麼在意ActiveMQ的設置相關。
目的
然後想着希望寫個程序或者腳本來監控生產的消息條數，當消息條數超過一次的條數就直接清空，然後發現ActiveMQ可以啓動JMX，配置JMX之後就可以連接了。
連接代碼
注意點
String url = "service:jmx:rmi:///jndi/rmi://192.168.1.134:1099/jmxrmi";這裏需要輸入自己ActiveMQ的IP和JMX的端口。
ObjectName name = new ObjectName("org.apache.activemq:brokerName=localhost,type=Broker");這裏的localhost是指當前ActiveMQ的節點名稱，不是隊列名稱，剛開始我輸入了的是隊列名稱，一直報錯，brokerName的名字可以在activemq的配置文件裏面看，也可以從activemq的控制裏面找，如下圖。
還有一個問題就是這裏的brokerName、type首字母必須小寫，
ActiveMQ 5.8.0 Release 這個版本修改了名稱
public class MonitorActiveMQ {
public static void main(String[] args) throws Exception {
String url = "service:jmx:rmi:///jndi/rmi://192.168.1.134:1099/jmxrmi";
JMXServiceURL urls = new JMXServiceURL(url);
JMXConnector connector = JMXConnectorFactory.connect(urls, null);
connector.connect();
MBeanServerConnection conn = connector.getMBeanServerConnection();
ObjectName name = new ObjectName("org.apache.activemq:brokerName=localhost,type=Broker");
BrokerViewMBean mBean = (BrokerViewMBean) MBeanServerInvocationHandler.newProxyInstance(conn, name, BrokerViewMBean.class, true);
for (ObjectName na : mBean.getQueues()) {
QueueViewMBean queueBean = (QueueViewMBean) MBeanServerInvocationHandler.newProxyInstance(conn, na, QueueViewMBean.class, true);
System.out.println("******************************");
System.out.println("隊列的名稱：" + queueBean.getName());
System.out.println("隊列中剩餘的消息數：" + queueBean.getQueueSize());
System.out.println("消費者數：" + queueBean.getConsumerCount());
System.out.println("出隊列的數量：" + queueBean.getDequeueCount());
queueBean.purge();
}
connector.close();
}
}
異常代碼
Exception in thread "main" java.lang.reflect.UndeclaredThrowableException
at com.sun.proxy.$Proxy0.getQueues(Unknown Source)
at com.imobpay.monitor.services.task.MonitorActiveMQ.main(MonitorActiveMQ.java:26)
Caused by: javax.management.InstanceNotFoundException: org.apache.activemq:brokerName=localhost2,type=Broker
at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.getMBean(DefaultMBeanServerInterceptor.java:1095)
at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.getAttribute(DefaultMBeanServerInterceptor.java:643)
at com.sun.jmx.mbeanserver.JmxMBeanServer.getAttribute(JmxMBeanServer.java:678)
at javax.management.remote.rmi.RMIConnectionImpl.doOperation(RMIConnectionImpl.java:1445)
at javax.management.remote.rmi.RMIConnectionImpl.access$300(RMIConnectionImpl.java:76)
at javax.management.remote.rmi.RMIConnectionImpl$PrivilegedOperation.run(RMIConnectionImpl.java:1309)
at javax.management.remote.rmi.RMIConnectionImpl.doPrivilegedOperation(RMIConnectionImpl.java:1401)
at javax.management.remote.rmi.RMIConnectionImpl.getAttribute(RMIConnectionImpl.java:639)
at sun.reflect.GeneratedMethodAccessor37.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:357)
at sun.rmi.transport.Transport$1.run(Transport.java:200)
at sun.rmi.transport.Transport$1.run(Transport.java:197)
at java.security.AccessController.doPrivileged(Native Method)
at sun.rmi.transport.Transport.serviceCall(Transport.java:196)
at sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:573)
at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(TCPTransport.java:834)
at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.lambda$run$0(TCPTransport.java:688)
at java.security.AccessController.doPrivileged(Native Method)
at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:687)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:748)
at sun.rmi.transport.StreamRemoteCall.exceptionReceivedFromServer(StreamRemoteCall.java:283)
at sun.rmi.transport.StreamRemoteCall.executeCall(StreamRemoteCall.java:260)
at sun.rmi.server.UnicastRef.invoke(UnicastRef.java:161)
at com.sun.jmx.remote.internal.PRef.invoke(Unknown Source)
at javax.management.remote.rmi.RMIConnectionImpl_Stub.getAttribute(Unknown Source)
at javax.management.remote.rmi.RMIConnector$RemoteMBeanServerConnection.getAttribute(RMIConnector.java:903)
at javax.management.MBeanServerInvocationHandler.invoke(MBeanServerInvocationHandler.java:273)
... 2 more
Process finished with exit code 1
總結
雖然這個問題挺簡單的，面向百度編程也很容易解決，主要是粗心，拷貝也不注意看。