RabbitMQ學習之Java客戶端連接測試（二）

前面花了幾天糾結完RabbitMQ在Linux下的安裝之後，開始找簡單的例子來測試RabbitMQ和Java的連接。

和前面的安裝一樣，問題依舊。因爲網上的帖子大多數都是很正常的步驟，並且沒有貼出來自己途中可能遇到的低級錯誤。

本文將沿用網上很經典的一個帖子來說出我過程中出現的低級問題。

如果您和我一樣是一個Linux和RabbitMQ的新手，首先不要一開始就想的太好太完美，首先從最簡單的做起。

不要去找那些看上去很高大上的帖子，也不要一開始就和maven以及spring去集成。就寫簡單的main方法，來測試是否能夠很順利的從Java連接成功RabbitMQ。

下面的例子是網上的，但是不知道原貼到底是誰的，我也稍微加工一下，彌補新手遺漏的一些信息。

1.首先需要去官網下載Java需要的jar包，建議先不要用maven依賴，慢慢來。

依次進入下面的路徑，這個是我現在最新的jar包路徑，下載解壓之後裏面就會有jar包，然後導入到項目中即可。

http://www.rabbitmq.com/releases/rabbitmq-java-client/

2.創建Java項目，並寫連接類，下面兩個類爲網上經典的類。

import java.io.IOException;
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.ConnectionFactory;

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

    public static void main(String[] args) throws IOException {  
        ConnectionFactory factory = new ConnectionFactory();  
        factory.setHost("10.10.6.246");
        factory.setUsername("admin");
        factory.setPassword("admin");
        factory.setPort(5672);
        Connection connection = factory.newConnection();  
        Channel channel = connection.createChannel();  

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

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

------------------------------------------------------------------------------------------------------

import com.rabbitmq.client.ConnectionFactory;
import com.rabbitmq.client.QueueingConsumer;
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;

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

    public static void main(String[] argv) throws Exception {
        ConnectionFactory factory = new ConnectionFactory();

        factory.setUsername("admin");
        factory.setPassword("admin");
        factory.setHost("10.10.6.246");
        factory.setVirtualHost("/"); 
        factory.setPort(5672);
        Connection connection = factory.newConnection();
        Channel channel = connection.createChannel();
        channel.queueDeclare(QUEUE_NAME, false, false, false, null);
        System.out.println(" [*] Waiting for messages. To exit press CTRL+C");
        QueueingConsumer consumer = new QueueingConsumer(channel);
        channel.basicConsume(QUEUE_NAME, true, consumer);
        while(true){
            QueueingConsumer.Delivery delivery = consumer.nextDelivery();
            String message = new String(delivery.getBody());
            System.out.println(" [x] Received '" + message + "'");
        }
    }
}

看似簡單的例子，如果RabbitMQ安裝的時候沒有弄好的話，依舊還是可能出現一些問題的，以下就是我的問題。

3.出現的問題。

    >>>第一個

Exception in thread "main" com.rabbitmq.client.PossibleAuthenticationFailureException: Possibly caused by authentication failure
    at com.rabbitmq.client.impl.AMQConnection.start(AMQConnection.java:355)
    at com.rabbitmq.client.ConnectionFactory.newConnection(ConnectionFactory.java:516)
    at com.rabbitmq.client.ConnectionFactory.newConnection(ConnectionFactory.java:533)
    at com.mq.test.Reqv.main(Reqv.java:30)
Caused by: com.rabbitmq.client.ShutdownSignalException: connection error; reason: java.net.SocketException: Connection reset
    at com.rabbitmq.utility.ValueOrException.getValue(ValueOrException.java:67)
    at com.rabbitmq.utility.BlockingValueOrException.uninterruptibleGetValue(BlockingValueOrException.java:33)
    at com.rabbitmq.client.impl.AMQChannel$BlockingRpcContinuation.getReply(AMQChannel.java:343)
    at com.rabbitmq.client.impl.AMQChannel.privateRpc(AMQChannel.java:216)
    at com.rabbitmq.client.impl.AMQChannel.rpc(AMQChannel.java:202)
    at com.rabbitmq.client.impl.AMQConnection.start(AMQConnection.java:347)
    ... 3 more
Caused by: java.net.SocketException: Connection reset
    at java.net.SocketInputStream.read(Unknown Source)
    at java.net.SocketInputStream.read(Unknown Source)
    at java.io.BufferedInputStream.fill(Unknown Source)
    at java.io.BufferedInputStream.read(Unknown Source)
    at java.io.DataInputStream.readUnsignedByte(Unknown Source)
    at com.rabbitmq.client.impl.Frame.readFrom(Frame.java:95)
    at com.rabbitmq.client.impl.SocketFrameHandler.readFrame(SocketFrameHandler.java:131)
    at com.rabbitmq.client.impl.AMQConnection$MainLoop.run(AMQConnection.java:515)

解決方案：

    >1.是不是覺得自己的用戶完全沒有問題，web端也能正常的連接上，用戶名，端口換了很多次，依舊還是不解到底是什麼問題呢？

    >2.此問題就是連接失敗，認證失敗，如果覺得自己所有的東西都已經弄好了，很有可能就是RabbitMQ的用戶權限出現了問題。

    

這個是我之前的用戶狀態，很明顯這個地方用戶權限是有問題的，因爲新手和無知，所以也找不出爲什麼。

# rabbitmqctl  set_permissions  -p  VHostPath【虛擬主機路徑  ‘/’】  User【用戶名字】  ".*" ".*" ".*"

# /etc/init.d/rabbitmq-server restart

重新設置用戶的權限之後重啓RabbitMQ，再次運行是否成功了呢？如果運行結果出現了：

[x]Sent 'hello world!'

----------------------------------------

[*] Waiting for messages. To exitpress CTRL+C

[x] Received 'hello world!'

那麼恭喜你終於解決了連接的問題了。

   >>>第二個

Exception in thread "main" java.io.IOException
	at com.rabbitmq.client.impl.AMQChannel.wrap(AMQChannel.java:106)
	at com.rabbitmq.client.impl.AMQChannel.wrap(AMQChannel.java:102)
	at com.rabbitmq.client.impl.AMQChannel.exnWrappingRpc(AMQChannel.java:124)
	at com.rabbitmq.client.impl.ChannelN.queueDeclare(ChannelN.java:768)
	at com.rabbitmq.client.impl.ChannelN.queueDeclare(ChannelN.java:61)
	at com.mq.test.Reqv.main(Reqv.java:32)
Caused by: com.rabbitmq.client.ShutdownSignalException: channel error; reason: {#method<channel.close>(reply-code=403, reply-text=ACCESS_REFUSED - access to queue 'hello' in vhost '/' refused for user 'admin', class-id=50, method-id=10), null, ""}
	at com.rabbitmq.utility.ValueOrException.getValue(ValueOrException.java:67)
	at com.rabbitmq.utility.BlockingValueOrException.uninterruptibleGetValue(BlockingValueOrException.java:33)
	at com.rabbitmq.client.impl.AMQChannel$BlockingRpcContinuation.getReply(AMQChannel.java:343)
	at com.rabbitmq.client.impl.AMQChannel.privateRpc(AMQChannel.java:216)
	at com.rabbitmq.client.impl.AMQChannel.exnWrappingRpc(AMQChannel.java:118)
	... 3 more
Caused by: com.rabbitmq.client.ShutdownSignalException: channel error; reason: {#method<channel.close>(reply-code=403, reply-text=ACCESS_REFUSED - access to queue 'hello' in vhost '/' refused for user 'admin', class-id=50, method-id=10), null, ""}
	at com.rabbitmq.client.impl.ChannelN.asyncShutdown(ChannelN.java:474)
	at com.rabbitmq.client.impl.ChannelN.processAsync(ChannelN.java:315)
	at com.rabbitmq.client.impl.AMQChannel.handleCompleteInboundCommand(AMQChannel.java:144)
	at com.rabbitmq.client.impl.AMQChannel.handleFrame(AMQChannel.java:91)
	at com.rabbitmq.client.impl.AMQConnection$MainLoop.run(AMQConnection.java:533)

第二個問題和第一個基本上差不多，意思就是無法訪問隊列信息，所以很有可能還是用戶權限的問題。如果按照上面的設置已經解決好了，事實上不會出現

這個問題了，所以解決方式和第一個是一樣的。

4.給出一篇RabbitMQ權限設置的帖子，以供參考。

http://my.oschina.net/hncscwc/blog/262246?fromerr=hs1eUWw0