rabbitMQ Connection timed out

在VM中部署了一个rabbitMQ server ,在物理机上按照rabbitMQ官网上的 java的教程访问VM中的rabbitMQ报如下错误：

Exception in thread "main" java.net.ConnectException: Connection timed out: connect
at java.net.DualStackPlainSocketImpl.waitForConnect(Native Method)
at java.net.DualStackPlainSocketImpl.socketConnect(Unknown Source)
at java.net.AbstractPlainSocketImpl.doConnect(Unknown Source)
at java.net.AbstractPlainSocketImpl.connectToAddress(Unknown Source)
at java.net.AbstractPlainSocketImpl.connect(Unknown Source)
at java.net.PlainSocketImpl.connect(Unknown Source)
at java.net.SocksSocketImpl.connect(Unknown Source)
at java.net.Socket.connect(Unknown Source)
at com.rabbitmq.client.impl.FrameHandlerFactory.create(FrameHandlerFactory.java:32)
at com.rabbitmq.client.ConnectionFactory.newConnection(ConnectionFactory.java:714)
at com.rabbitmq.client.ConnectionFactory.newConnection(ConnectionFactory.java:760)
at Send.main(Send.java:16)

代码示例：

import com.rabbitmq.client.ConnectionFactory;
import com.rabbitmq.client.Connection;
import java.util.concurrent.TimeoutException;
import com.rabbitmq.client.Channel;

public class Send {
    private final static String QUEUE_NAME = "hello";

    public static void main(String[] args) throws java.io.IOException, TimeoutException {

            ConnectionFactory factory = new ConnectionFactory();
            factory.setHost("192.168.198.100");
            factory.setPort(5672);
            Connection connection = factory.newConnection();
            Channel channel = connection.createChannel();

            channel.queueDeclare(QUEUE_NAME, false, false, false, null);
            String message = "Hello World from Windows!";
            channel.basicPublish("", QUEUE_NAME, null, message.getBytes());
            System.out.println(" [x] Sent '" + message + "'");

            channel.close();
            connection.close();

        }
    }

解决方案：

第一步.上面代码默认是使用rabbitMQ的默认用户“guest”作为登录用户，但是该用户不用许远程IP登录,所以我们需要自己在rabbitMQ中新增一个用户

//新增admin 密码admin
rabbitmqctl add_user admin admin　　　　
//将admin用户设置为administrator
rabbitmqctl set_user_tags admin administrator
//给admin所有的权限
rabbitmqctl set_permissions -p / admin".*" ".*" ".*"

　　然后增加如下Java代码：

factory.setPassword("test");
factory.setUsername("test");

第二.开启rabbitMQ的管理UI界面

rabbitmq-plugins enable rabbitmq_management

第三.检查防火墙是否开启了5672和15672端口,Centos7如何开启端口看这里

使用telnet测试

扩展.常见错误

1、如果写错了host （如：factory.setHost("locathost"); ）报错：

Exception in thread "main" Java.NET.UnknownHostException: locathost
at java.Net.PlainSocketImpl.connect(PlainSocketImpl.java:195)
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:366)
at java.net.Socket.connect(Socket.java:529)
at com.rabbitmq.client.impl.FrameHandlerFactory.create(FrameHandlerFactory.java:32)
at com.rabbitmq.client.ConnectionFactory.newConnection(ConnectionFactory.java:588)
at com.rabbitmq.client.ConnectionFactory.newConnection(ConnectionFactory.java:612)
at com.aaa.test.Send.main(Send.java:19)

2、如果写错端口PORT（如：factory.setPort(5678);） 报错：

Exception in thread "main" java.net.ConnectException: Connection refused: connect
at java.net.PlainSocketImpl.socketConnect(Native Method)
at java.net.PlainSocketImpl.doConnect(PlainSocketImpl.java:351)
at java.net.PlainSocketImpl.connectToAddress(PlainSocketImpl.java:213)
at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:200)
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:366)
at java.net.Socket.connect(Socket.java:529)
at com.rabbitmq.client.impl.FrameHandlerFactory.create(FrameHandlerFactory.java:32)
at com.rabbitmq.client.ConnectionFactory.newConnection(ConnectionFactory.java:588)
at com.rabbitmq.client.ConnectionFactory.newConnection(ConnectionFactory.java:612)
at com.aaa.test.Send.main(Send.java:19)

3、如果写错用户名或者密码，报错：

Exception in thread "main" com.rabbitmq.client.AuthenticationFailureException: ACCESS_REFUSED - Login was refused using authentication mechanism PLAIN. 
For details see the broker logfile.
at com.rabbitmq.client.impl.AMQConnection.start(AMQConnection.java:338)
at com.rabbitmq.client.ConnectionFactory.newConnection(ConnectionFactory.java:590)
at com.rabbitmq.client.ConnectionFactory.newConnection(ConnectionFactory.java:612)
at com.aaa.test.Send.main(Send.java:19)