消息中间件RabbitMq的代码使用案例

消费者：

---------------------- 构造初始化：

public RabbitMqReceiver(String host, int port, String username, String password) 
{
    connFactory = new ConnectionFactory();
    connFactory.setHost(host);
    connFactory.setPort(port);
    connFactory.setUsername(username);
    connFactory.setPassword(password);
}
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---------------------- 构造初始化：

    public Channel createChannel() throws IOException {
        getConnection();
        Channel channel = connection.createChannel();
        if (channel != null) {

　　　　　　     int prefetchCount = 1;

　　　　　　     channel.basicQos(prefetchCount);//最多为当前接收方发送一条消息。若是接收方还未处理完毕消息，尚未回发确认，就不要再给他分配消息了，应该把当前消息分配给其它空闲接收方。

　　　　　　　 boolean durable = true; //Server端的Queue持久化
　　　　　　　 channel.queueDeclare("task_queue", durable, false, false, null); 
            logger.info(mqInfo.getAddress() + ":" + mqInfo.getPort() + " MQ Receiver成功建立Channel");
        } else {
            logger.info(mqInfo.getAddress() + ":" + mqInfo.getPort() + " MQ Receiver建立Channel失败");
        }

        return channel;
    }

********************************************************************************

---------------------- 取得connection实例：

private void getConnection() throws IOException
 {
        synchronized (this) {
            if (connection == null || !connection.isOpen()) {
                connection = connFactory.newConnection();
                if (connection != null) {
                    logger.info(mqInfo.getAddress() + ":" + mqInfo.getPort() + " MQ Receiver成功获取链接");
                } else {
                    logger.info(mqInfo.getAddress() + ":" + mqInfo.getPort() + " MQ Receiver获取链接失败");
                }
            } else {
                logger.info(mqInfo.getAddress() + ":" + mqInfo.getPort() + " MQ Receiver链接已存在，复用此链接");
            }
        }
  }

********************************************************************************

----------------------获取Consumer实例：

public QueueingConsumer createConsumer(Channel channel, String queueName) throws IOException {
    QueueingConsumer consumer = new QueueingConsumer(channel);
    channel.basicConsume(queueName, true, consumer);   //自动消息确认打开，默认开启了消息确认（接收方接收到消息后，当即向服务器发回确认）。消息接收方处理完消息后，向服务器发送消息确认，服务器再删除该消息。

    return consumer;
}

********************************************************************************

----------------------从从rabbitMQ提取消息并转换为对象：

private String getMessageFromMQ() {
    String message = StringUtils.EMPTY;
    String source = StringUtils.EMPTY;
    try {
        message = receiver.nextMessage(checkNotNull(consumer), 1000);
        source = message;
    } catch (ShutdownSignalException e) {
        logger.error("", e);
    } catch (ConsumerCancelledException e) {
        logger.error("consumer exception", e);
    } catch (InterruptedException e) {
        logger.error("timeout exception", e);
    }
    try {
        if (StringUtils.isNotBlank(message)) {
            message = checkNotNull(StringUtils.substringAfter(message, "yyy:"), "xxx");
            message = checkNotNull(StringEscapeUtils.unescapeJava(message), "unescape error");
            int size = message.length();
            if (size > 1) {
                message = checkNotNull(message.substring(0, message.length() - 1), "get json-data error");// 去掉末尾的”
            } else {
                logger.warn(String.format("数据异常,message=%s", source));
            }
        }
    } catch (Throwable e) {
        logger.error(String.format("数据异常,message=%s", source), e);
    }
    return message;
}

********************************************************************************

----------------------每次读取一条消息：

public String nextMessage(QueueingConsumer consumer, long timeOut) throws ShutdownSignalException, ConsumerCancelledException, InterruptedException {

    QueueingConsumer.Delivery delivery;
    if (timeOut > 0) {
        delivery = consumer.nextDelivery(timeOut);
    } else {
        delivery = consumer.nextDelivery();
    }
    if (delivery == null) {
        return StringUtils.EMPTY;
    }

    String message = new String(delivery.getBody());
    return message;
}

********************************************************************************

---------------------- 在storm中建立mq实例：

SpoutOutputCollector collector;
RabbitMqReceiver receiver;
Channel channel;
QueueingConsumer consumer;

public void open(Map conf, TopologyContext context, SpoutOutputCollector collector)  //初始化调用一次
{
    this.collector = collector;
    receiver = checkNotNull(new RabbitMqReceiver(conf.get("crash.mq.host").toString(),
                    Integer.valueOf(conf.get("crash.mq.port").toString()), conf.get("crash.mq.user").toString(),
                    conf.get("crash.mq.pwd").toString()), "receiver is null");
    try {
        channel = checkNotNull(receiver.createChannel(), "channel is null");
        consumer = checkNotNull(receiver.createConsumer(channel, conf.get("crash.mq.channel").toString()),
                                "comsumer is null");
    } catch (Exception e) {
        logger.error("init mq-client error:", e);
    }
}

---------------------- 在storm中循环执行得到消息实例：

@Override
public void nextTuple() 
{
    String message = getMessageFromMQ();
}

生产者：
--------------------------------------------------：


private final static String QUEUE_NAME = "hello2";// 队列名不能重复 以前已有就会失败 

public class Producer {  

    private final static String QUEUE_NAME = "hello2";// 队列名不能重复 以前已有就会失败  

    public static void main(String[] argv) throws java.io.IOException {  

        /* 使用工厂类创建Connection和Channel，而且设置参数 */  
        ConnectionFactory factory = new ConnectionFactory();  
        factory.setHost("192.168.10.111");// MQ的IP  
        factory.setPort(5672);// MQ端口  
        factory.setUsername("asdf");// MQ用户名  
        factory.setPassword("123456");// MQ密码  
        Connection connection = factory.newConnection();  
        Channel channel = connection.createChannel();  

        /* 建立消息队列，而且发送消息 */  
        channel.queueDeclare(QUEUE_NAME, false, false, false, null);  
        String message = "消息2";  
        channel.basicPublish("", QUEUE_NAME, MessageProperties.PERSISTENT_TEXT_PLAIN, message.getBytes());  //Message持久化
        System.out.println("生产了个'" + message + "'");  

        /* 关闭链接 */  
        channel.close();  
        connection.close();  
    }  

}