Question

我正在开发 Spring + ActiveMQ + JMS 示例。在这个例子中，我面临以下错误：我尝试了很多选项，但根本没有工作。

我希望实施以下内容：

1）队列应该继续阅读消息（使用转换器或监听器）

2）根据InstructionMessage类型，我必须决定发送或不发送的位置。

上传的代码为：https://github.com/test512/spring-mvc-jms-tutorials

Sending person InstructionMessage [instructionType=10, productCode=10, quantity=10, uOM=10, timeStamp=10]
Exception in thread "main" org.springframework.jms.support.converter.MessageConversionException: Cannot convert object of type [com.jms.testing.spring.InstructionMessage] to JMS message. Supported message payloads are: String, byte array, Map<String,?>, Serializable object.
    at org.springframework.jms.support.converter.SimpleMessageConverter.toMessage(SimpleMessageConverter.java:78)
    at org.springframework.jms.core.JmsTemplate$5.createMessage(JmsTemplate.java:651)
    at org.springframework.jms.core.JmsTemplate.doSend(JmsTemplate.java:593)
    at org.springframework.jms.core.JmsTemplate$3.doInJms(JmsTemplate.java:562)
    at org.springframework.jms.core.JmsTemplate.execute(JmsTemplate.java:484)
    at org.springframework.jms.core.JmsTemplate.send(JmsTemplate.java:559)
    at org.springframework.jms.core.JmsTemplate.convertAndSend(JmsTemplate.java:648)
    at org.springframework.jms.core.JmsTemplate.convertAndSend(JmsTemplate.java:639)
    at com.jms.testing.spring.SpringJmsPersonProducer.sendMessage(SpringJmsPersonProducer.java:18)
    at com.jms.testing.spring.SpringJmsMessageConverterExample.main(SpringJmsMessageConverterExample.java:16)

appContextWithMessageConverter.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:context="http://www.springframework.org/schema/context"
    xmlns:jms="http://www.springframework.org/schema/jms"
    xsi:schemaLocation="http://www.springframework.org/schema/jms http://www.springframework.org/schema/jms/spring-jms.xsd
        http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">

    <context:property-placeholder location="classpath:jms.properties" />

    <bean id="jmsConnectionFactory" class="org.apache.activemq.ActiveMQConnectionFactory">
        <property name="brokerURL" value="${jms.brokerURL}" />
    </bean>

    <bean id="pooledJmsConnectionFactory" class="org.apache.activemq.pool.PooledConnectionFactory" destroy-method="stop">
        <property name="connectionFactory" ref="jmsConnectionFactory" />
        <property name="maxConnections" value="50" />
    </bean>

    <jms:listener-container container-type="default" connection-factory="pooledJmsConnectionFactory" acknowledge="auto" >
        <!-- <jms:listener destination="messageDestination" ref="messageDestination" /> -->
        <jms:listener destination="messageDestination" ref="myListener" />
    </jms:listener-container>

    <bean id="instructionMessageConverter" class="com.jms.testing.spring.InstructionMessageConverter" />

    <bean id="myListener" class="com.jms.testing.spring.MyListener" />

    <bean id="jmsTemplate" class="org.springframework.jms.core.JmsTemplate">
        <constructor-arg ref="pooledJmsConnectionFactory" />
        <property name="defaultDestination" ref="messageDestination" />
        <property name="receiveTimeout" value="${jms.receiveTimeout}" />
        <!-- <property name="messageConverter" ref="instructionMessageConverter" /> -->

    </bean>

    <bean id="springJmsPersonProducer" class="com.jms.testing.spring.SpringJmsPersonProducer">
        <property name="jmsTemplate" ref="jmsTemplate" />
    </bean>

    <bean id="springJmsPersonConsumer" class="com.jms.testing.spring.SpringJmsPersonConsumer">
        <property name="jmsTemplate" ref="jmsTemplate" />
    </bean> 

    <bean id="messageDestination" class="org.apache.activemq.command.ActiveMQQueue">
        <constructor-arg value="messageQueue1" />
    </bean>
</beans>

MyListener.java

public class MyListener implements MessageListener {

    @Override
    public void onMessage(Message message) {
        MapMessage mapMessage = (MapMessage) message;

        try {
            int instructionType = Integer.parseInt(mapMessage.getString("instructionType"));
            int productCode = Integer.parseInt(mapMessage.getString("productCode"));
            int quantity = Integer.parseInt(mapMessage.getString("quantity"));
            int timeStamp = Integer.parseInt(mapMessage.getString("timeStamp"));
            int uOM = Integer.parseInt(mapMessage.getString("uOM"));
            InstructionMessage instructionMessage = new InstructionMessage(instructionType, productCode, quantity, uOM,
                    timeStamp);
            System.out.println(instructionMessage.toString());

        } catch (NumberFormatException | JMSException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

    }
}

InstructionMessage.java

public class InstructionMessage implements Serializable{

private static final long serialVersionUID = 1L;
    private int instructionType;
    private int productCode;
    private int quantity;
    private int uOM;
    private int timeStamp;


    public InstructionMessage(int instructionType, int productCode, int quantity, int uOM, int timeStamp) {
        super();
        this.instructionType = instructionType;
        this.productCode = productCode;
        this.quantity = quantity;
        this.uOM = uOM;
        this.timeStamp = timeStamp;
    }

    public int getInstructionType() {
        return instructionType;
    }

    public void setInstructionType(int instructionType) {
        this.instructionType = instructionType;
    }

    public int getProductCode() {
        return productCode;
    }

    public void setProductCode(int productCode) {
        this.productCode = productCode;
    }

    public int getQuantity() {
        return quantity;
    }

    public void setQuantity(int quantity) {
        this.quantity = quantity;
    }

    public int getuOM() {
        return uOM;
    }

    public void setuOM(int uOM) {
        this.uOM = uOM;
    }

    public int getTimeStamp() {
        return timeStamp;
    }

    public void setTimeStamp(int timeStamp) {
        this.timeStamp = timeStamp;
    }

    @Override
    public String toString() {
        return "InstructionMessage [instructionType=" + instructionType + ", productCode=" + productCode + ", quantity="
                + quantity + ", uOM=" + uOM + ", timeStamp=" + timeStamp + "]";
    }
}

SpringJmsMessageConverterExample.java

public class SpringJmsMessageConverterExample {
    public static void main(String[] args) throws URISyntaxException, Exception {
        ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext(
                "appContextWithMessageConverter.xml");

        try {
            SpringJmsPersonProducer springJmsProducer = (SpringJmsPersonProducer) context.getBean("springJmsPersonProducer");
            InstructionMessage m1 = new InstructionMessage(10,10,10,10,10);
            System.out.println("Sending person " + m1);
            springJmsProducer.sendMessage(m1);

            InstructionMessage m2 = new InstructionMessage(5,5,5,5,5);
            System.out.println("Sending person " + m2);
            springJmsProducer.sendMessage(m2);

            InstructionMessage m3 = new InstructionMessage(0,0,0,0,0);
            System.out.println("Sending person " + m3);
            springJmsProducer.sendMessage(m3);

            System.out.println("~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~");

            SpringJmsPersonConsumer springJmsConsumer = (SpringJmsPersonConsumer) context.getBean("springJmsPersonConsumer");
            System.out.println("Consumer receives " + springJmsConsumer.receiveMessage());
        } finally {
            context.close();
        }
    }
}

SpringJmsPersonProducer.java

public class SpringJmsPersonProducer {

    private JmsTemplate jmsTemplate;

    public JmsTemplate getJmsTemplate() {
        return jmsTemplate;
    }

    public void setJmsTemplate(JmsTemplate jmsTemplate) {
        this.jmsTemplate = jmsTemplate;
    }

    public void sendMessage(final InstructionMessage instructionMessage) {
        getJmsTemplate().convertAndSend(instructionMessage);
    }
}

SpringJmsPersonConsumer.java

public class SpringJmsPersonConsumer {

    private JmsTemplate jmsTemplate;

    public JmsTemplate getJmsTemplate() {
        return jmsTemplate;
    }

    public void setJmsTemplate(JmsTemplate jmsTemplate) {
        this.jmsTemplate = jmsTemplate;
    }

    public InstructionMessage receiveMessage() throws JMSException {
        InstructionMessage instructionMessage = (InstructionMessage) getJmsTemplate().receiveAndConvert();
        return instructionMessage;  
    }
}

Answer 1

只需添加生成的序列版本ID，而不是默认的1L！

public class InstructionMessage implements Serializable{

private static final long serialVersionUID = -295422703255886286L;

更新：

<强> 1）为了让您的听众正常工作，您需要更新 destination =“messageQueue1 ，因为 messageDestination 容器会创建此队列，并且您的邮件会发送到 messageQueue1 ：

<jms:listener-container container-type="default"
    connection-factory="pooledJmsConnectionFactory" acknowledge="auto">
    <jms:listener destination="messageQueue1" ref="myListener" />
</jms:listener-container>

并更新 MyListener

import javax.jms.JMSException;
import javax.jms.Message;
import javax.jms.MessageListener;
import javax.jms.ObjectMessage;

public class MyListener implements MessageListener {

    @Override
    public void onMessage(Message message) {
        try {
            ObjectMessage mapMessage = (ObjectMessage) message;
            InstructionMessage instructionMessage = (InstructionMessage) mapMessage.getObject();
            System.out.println(instructionMessage.toString());
        } catch (NumberFormatException | JMSException e) {
            e.printStackTrace();
        }
    }
}

2）有条件发送

import org.springframework.jms.core.JmsTemplate;

public class SpringJmsPersonProducer {

    private JmsTemplate jmsTemplate;

    public JmsTemplate getJmsTemplate() {
        return jmsTemplate;
    }

    public void setJmsTemplate(JmsTemplate jmsTemplate) {
        this.jmsTemplate = jmsTemplate;
    }

    public void sendMessage(final InstructionMessage instructionMessage) {
        if (canSend(instructionMessage)) {
            getJmsTemplate().convertAndSend(instructionMessage);
        } else {
            throw new IllegalArgumentException("message");
        }
    }

    private boolean canSend(InstructionMessage instructionMessage) {
        return instructionMessage.getQuantity() > 0;
    }
}

Answer 2

JMS将数据移动到不同的JVM。不能用普通物体做。必须序列化，因此需要实现Serializable接口假设可以这样做，请问主建筑师

import java.io.Serializable;
...
public class InstructionMessage implements Serializable {

 private static final long serialVersionUID = 7526472295622776147L;

....
}

背景：网络不了解Java对象，只能传输字节。是Java开发的基础，任何书都可以提供帮助（Eckel用Java思考）

编辑：部分答案（尝试回答）您已更改（使用Serializable）代码。现在ClassCastException例外说：发送和接收部分互不兼容。框架或服务器转换InstructionMessage - ＆gt; HashMap，我想早期阶段。

我猜也是，但在这里我几乎可以肯定，HashMap内容在功能上是相同的。

最简单但不优雅的方法是离开InstructionMessage并双方使用HashMap（更改发件人）或调试问题。

如果我记得，你删除了Converter类java，但保留在XML中。我不是一个大的春天粉丝（个人讨厌＆＃34; xml编程＆＃34;），我想用XML进行一些修正可以帮助

Answer 3

请改用Jackson转换，在需要触发多个事件对象的事件驱动系统中方便使用

@Bean
public JmsTemplate jmsTemplate() {
    JmsTemplate template = new JmsTemplate();
    template.setConnectionFactory(connectionFactory());
    template.setMessageConverter(jacksonJmsMessageConverter());
    template.setPubSubDomain(true);
    return template;
}

@Bean
public MessageConverter jacksonJmsMessageConverter() {
    MappingJackson2MessageConverter converter = new MappingJackson2MessageConverter();
    converter.setTargetType(MessageType.TEXT);
    converter.setTypeIdPropertyName("_type");
    return converter;
}

然后设置

containerFactory.setMessageConverter（jacksonJmsMessageConverter（））;

就是这样。

无法将类型的对象转换为JMS消息。支持的消息有效负载包括：字符串，字节数组，Map <string，？>，Serializable对象

3 个答案: