RabbitMQ RPC方式调用

队列配置、生产者配置、消费者配置和一般的mq配置相同。
reply-timeout是过期时间，可以写到配置文件中。

<rabbit:template id="template" message-converter="messageConverter"
    connection-factory="connectionFactory" reply-timeout="2000" retry-template="retryTemplate" 
    exchange="${rabbitmq.direct.exchange}"  />

1.生产者代码示例
使用template.convertSendAndReceive方法即为RPC调用，本例中使用了direct模式，也可以使用fanout和topic。

public class MqBlocking extends BaseTask {
     

    @Override
    protected void execute(final ScheduleJob scheduleJob, final String id) {
        RabbitTemplate template = (RabbitTemplate) SpringContextHolder.getBean("template");
        BaseResponse obj = (BaseResponse) template.convertSendAndReceive(template.getExchange(), "ccs.binding." + scheduleJob.getMqName(), id, new MessagePostProcessor() {
            @Override
            public Message postProcessMessage(Message message) throws AmqpException {
                message.getMessageProperties().setHeader("jobName", scheduleJob.getName());
                return message;
            }
        });
    }

}

2.消费者代码示例

@RabbitListener(queues = "ccs.queue.blocking")
public BaseResponse helloBlocking(String id, @Header("jobName") String jobName) {
    System.out.println("Received request for id " + id);
    System.out.println("Received request for job name " + jobName);
    //返回执行结果（成功，失败）和ID
    BaseResponse response = new BaseResponse(true, id);
    return response;
}

3.代码实现方式
因为低版本的mq不支持注解，只能使用代码来配置监听器
消费者配置

    
    <bean id="messageConverter" class="org.springframework.amqp.support.converter.JsonMessageConverter" />
    
    <rabbit:queue name="ccs.queue.blocking" />
    <rabbit:direct-exchange name="ccs.direct.exchange">
        <rabbit:bindings>
            <rabbit:binding queue="ccs.queue.blocking" key="ccs.binding.blocking" />
        rabbit:bindings>
    rabbit:direct-exchange>
    
    <rabbit:listener-container connection-factory="connectionFactory" message-converter="jsonMessageConverter">
        <rabbit:listener ref="queueHandler" method="handle" queues="ccs.queue.blocking" />
    rabbit:listener-container>

消费者代码

package com.whty.bwjf.tsp.cm.controller;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.amqp.core.Message;
import org.springframework.amqp.core.MessageProperties;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;

import com.whty.bwjf.framework.core.util.JsonMessageConverter;
import com.whty.framework.base.web.mvc.view.BaseResponse;

@Component
public class QueueHandler {
     

    @Autowired
    private JsonMessageConverter messageConverter;
    Logger logger = LoggerFactory.getLogger(QueueHandler.class);

    public Message handle(Message message)
    {
        System.out.println("Received request for jobname " + message.getMessageProperties().getHeaders().get("jobName"));
        String id = (String) messageConverter.fromMessage(message);
        System.out.println("Received request for id " + id);
        //返回执行结果（成功，失败）和ID
        BaseResponse response = new BaseResponse(true, id);
        return messageConverter.toMessage(response, new MessageProperties());
    }
}

PS：有可能在第一次加上这些配置的时候，消息会先经过Converter，但是Converter中转换为实体类型后，就无法进入到handle中。
可以配置一个空转换器来解决此问题

package com.whty.bwjf.framework.core.util;

import java.io.UnsupportedEncodingException;

import org.springframework.amqp.core.Message;
import org.springframework.amqp.core.MessageProperties;
import org.springframework.amqp.support.converter.AbstractMessageConverter;
import org.springframework.amqp.support.converter.MessageConversionException;

import com.alibaba.fastjson.JSON;

@Component
public class OriginMessageConverter  extends AbstractMessageConverter {
     

    public OriginMessageConverter() {
        super();
    }

    public void setDefaultCharset(String defaultCharset) {
        this.defaultCharset = (defaultCharset != null) ? defaultCharset
                : DEFAULT_CHARSET;
    }

    public Object fromMessage(Message message)
            throws MessageConversionException {
        return message;
    }

    protected Message createMessage(Object objectToConvert,
            MessageProperties messageProperties)
            throws MessageConversionException {
        return (Message) objectToConvert;

    }
}

    <rabbit:listener-container connection-factory="connectionFactory" message-converter="originMessageConverter">
        <rabbit:listener ref="queueHandler" method="handle" queues="crm.hb.queue" />
    rabbit:listener-container>