ActiveMQ 生产者发送消息失败：refuse connect

在生产者发送消息时，出现如下报错：

java.net.ConnectException: Connection refused: connect
	at java.net.DualStackPlainSocketImpl.waitForConnect(Native Method) ~[na:1.8.0_181]
	at java.net.DualStackPlainSocketImpl.socketConnect(DualStackPlainSocketImpl.java:85) ~[na:1.8.0_181]
	at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:350) ~[na:1.8.0_181]
	at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:206) ~[na:1.8.0_181]
	at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:188) ~[na:1.8.0_181]
	at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:172) ~[na:1.8.0_181]
	at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392) ~[na:1.8.0_181]
	at java.net.Socket.connect(Socket.java:589) ~[na:1.8.0_181]
	at org.apache.activemq.transport.tcp.TcpTransport.connect(TcpTransport.java:525) ~[activemq-client-5.14.5.jar:5.14.5]
	at org.apache.activemq.transport.tcp.TcpTransport.doStart(TcpTransport.java:488) ~[activemq-client-5.14.5.jar:5.14.5]
	at org.apache.activemq.util.ServiceSupport.start(ServiceSupport.java:55) ~[activemq-client-5.14.5.jar:5.14.5]
	at org.apache.activemq.transport.AbstractInactivityMonitor.start(AbstractInactivityMonitor.java:169) ~[activemq-client-5.14.5.jar:5.14.5]
	at org.apache.activemq.transport.InactivityMonitor.start(InactivityMonitor.java:52) ~[activemq-client-5.14.5.jar:5.14.5]
	at org.apache.activemq.transport.TransportFilter.start(TransportFilter.java:64) ~[activemq-client-5.14.5.jar:5.14.5]
	at org.apache.activemq.transport.WireFormatNegotiator.start(WireFormatNegotiator.java:72) ~[activemq-client-5.14.5.jar:5.14.5]
	at org.apache.activemq.transport.TransportFilter.start(TransportFilter.java:64) ~[activemq-client-5.14.5.jar:5.14.5]
	at org.apache.activemq.transport.TransportFilter.start(TransportFilter.java:64) ~[activemq-client-5.14.5.jar:5.14.5]
	at org.apache.activemq.ActiveMQConnectionFactory.createActiveMQConnection(ActiveMQConnectionFactory.java:354) ~[activemq-client-5.14.5.jar:5.14.5]
	at org.apache.activemq.ActiveMQConnectionFactory.createActiveMQConnection(ActiveMQConnectionFactory.java:304) ~[activemq-client-5.14.5.jar:5.14.5]
	at org.apache.activemq.ActiveMQConnectionFactory.createConnection(ActiveMQConnectionFactory.java:244) ~[activemq-client-5.14.5.jar:5.14.5]
	at org.springframework.jms.support.JmsAccessor.createConnection(JmsAccessor.java:180) ~[spring-jms-4.3.8.RELEASE.jar:4.3.8.RELEASE]
	at org.springframework.jms.core.JmsTemplate.execute(JmsTemplate.java:474) ~[spring-jms-4.3.8.RELEASE.jar:4.3.8.RELEASE]
	at org.springframework.jms.core.JmsTemplate.send(JmsTemplate.java:559) ~[spring-jms-4.3.8.RELEASE.jar:4.3.8.RELEASE]
	at org.springframework.jms.core.JmsMessagingTemplate.doSend(JmsMessagingTemplate.java:325) ~[spring-jms-4.3.8.RELEASE.jar:4.3.8.RELEASE]
	at org.springframework.jms.core.JmsMessagingTemplate.doSend(JmsMessagingTemplate.java:46) ~[spring-jms-4.3.8.RELEASE.jar:4.3.8.RELEASE]
	at org.springframework.messaging.core.AbstractMessageSendingTemplate.send(AbstractMessageSendingTemplate.java:105) ~[spring-messaging-4.3.8.RELEASE.jar:4.3.8.RELEASE]
	at org.springframework.messaging.core.AbstractMessageSendingTemplate.convertAndSend(AbstractMessageSendingTemplate.java:143) ~[spring-messaging-4.3.8.RELEASE.jar:4.3.8.RELEASE]
	at org.springframework.messaging.core.AbstractMessageSendingTemplate.convertAndSend(AbstractMessageSendingTemplate.java:123) ~[spring-messaging-4.3.8.RELEASE.jar:4.3.8.RELEASE]
	at org.springframework.messaging.core.AbstractMessageSendingTemplate.convertAndSend(AbstractMessageSendingTemplate.java:118) ~[spring-messaging-4.3.8.RELEASE.jar:4.3.8.RELEASE]
	at fatcats.cloud.mq.RegisterMailboxProd.sendMsg(RegisterMailboxProd.java:22) ~[classes/:na]
	at fatcats.cloud.api.service.impl.MemberServiceImpl.sendMsg(MemberServiceImpl.java:103) ~[classes/:na]
	at fatcats.cloud.api.service.impl.MemberServiceImpl.register(MemberServiceImpl.java:85) ~[classes/:na]
           

联想到很多的可能性：

1.端口被占用

2.不在同一网络，即防火墙保护

3.服务器未启动

4.端口不正确

按照思路排查一下子就解决了