JMS消息传递实现

Question

I've been struggling with this "simple" task for more expirienced people, I'm stuck for 2 days now need help. I've changed things arround like zillion times now, finally I stumbled upon this spring JMS tutorial .

What I want to do, Send a message and receive it. I've been also reading this book chapter 8 on messaging. It really nicely explains 2 type of messaging and there is nice example for publish-and-subscribe type but now example for point-to-point messaging( this is the one I need ).

I'm able to send message to the queue on my own, but don't have a clue how to receive thats why I tried with this spring tutorial here is what I've got so far :

RE-EDITED SENDER :

package quartz.spring.com.example; 

import java.util.HashMap; 
import java.util.Map; 

import javax.jms.ConnectionFactory; 
import javax.jms.Destination; 
import javax.jms.JMSException; 
import javax.jms.Message; 
import javax.jms.Queue; 
import javax.jms.Session; 

import org.springframework.jms.core.MessageCreator; 
import org.springframework.jms.core.JmsTemplate; 
import org.springframework.jms.core.JmsTemplate102; 
import org.springframework.jms.core.MessagePostProcessor; 

public class JmsQueueSender { 

    private JmsTemplate jmsTemplate; 
    private Destination destination; 

    public void setConnectionFactory(ConnectionFactory cf) { 
        this.jmsTemplate = new JmsTemplate102(cf, false); 
    } 

    public void setQueue(Queue queue) { 
        this.destination = queue; 
    } 

    public void simpleSend() { 
        this.jmsTemplate.send(this.destination, new MessageCreator() { 
            public Message createMessage(Session session) throws JMSException { 
              return session.createTextMessage("hello queue world"); 
            } 
        }); 
    } 

    public void sendWithConversion() { 
        Map map = new HashMap(); 
        map.put("Name", "Mark"); 
        map.put("Age", new Integer(47)); 
        jmsTemplate.convertAndSend("ReceiverQueue", map, new MessagePostProcessor() { 
            public Message postProcessMessage(Message message) throws JMSException { 
                message.setIntProperty("AccountID", 1234); 
                message.setJMSCorrelationID("123-00001"); 
                return message; 
            } 
        }); 
    } 
} 

RECEIVER :

package quartz.spring.com.example;

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

public class ExampleListener implements MessageListener {

    public void onMessage(Message message) {
        if (message instanceof TextMessage) {
            try {
                System.out.println(((TextMessage) message).getText());
            }
            catch (JMSException ex) {
                throw new RuntimeException(ex);
            }
        }
        else {
            throw new IllegalArgumentException("Message must be of type TextMessage");
        }
    }
}

re-edited applicationcontext.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:jee="http://www.springframework.org/schema/jee" 
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.0.xsd 
        http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee-2.0.xsd"> 

    <bean id="sender" class="quartz.spring.com.example.JmsQueueSender" 
        init-method="sendWithConversion" /> 
    <bean id="receiver" class="quartz.spring.com.example.ExampleListener"> 
    </bean>  

    <bean id="jmsContainer" 
        class="org.springframework.jms.listener.DefaultMessageListenerContainer"> 
        <property name="connectionFactory" ref="connectionFactory" /> 
        <property name="destination" ref="queueDestination" /> 
        <property name="messageListener" ref="messageListener" /> 
    </bean> 

    <!-- Queue configuration --> 
    <bean id="jndiTemplate" class="org.springframework.jndi.JndiTemplate"> 
        <property name="environment"> 
            <props> 
                <prop key="java.naming.factory.initial">org.jnp.interfaces.NamingContextFactory</prop> 
                <prop key="java.naming.provider.url">jnp://localhost:1099</prop> 
                <prop key="java.naming.factory.url.pkgs">org.jboss.naming:org.jnp.interfaces</prop> 
                <prop key="java.naming.security.principal">admin</prop> 
                <prop key="java.naming.security.credentials">admin</prop> 
            </props> 
        </property> 
    </bean> 

    <bean id="connectionFactory" class="org.springframework.jndi.JndiObjectFactoryBean"> 
        <property name="jndiTemplate" ref="jndiTemplate" /> 
        <property name="jndiName" value="ConnectionFactory" /> 
    </bean> 

    <bean id="queueDestination" class="org.springframework.jndi.JndiObjectFactoryBean"> 
        <property name="jndiTemplate" ref="jndiTemplate" /> 
        <property name="jndiName"> 
            <value>queue/ReceiverQueue</value> 
        </property> 
    </bean> 
</beans> 

Didn't really know that learning curve for this is so long, I mean the idea is very simple:

1. Send message to the destination queue
2. Receive message from the destination queue

To receive messages, you do the following (so does book say):

1 Locate a ConnectionFactory, typically using JNDI.
2 Use the ConnectionFactory to create a Connection.
3 Use the Connection to create a Session.
4 Locate a Destination, typically using JNDI.
5 Use the Session to create a MessageConsumer for that Destination.

Once you've done this, methods on the MessageConsumer enable you to either query the Destination for messages or to register for message notification.

Can somebody please direct me towards right direction, is there a tutorial which explains in details how to receive message from the queue?I have the working send message code, didn't post it here because this post is too long as it is. EDIT:

I added to my jboss messaging destination-service.xml this Mbean :

<mbean code="org.jboss.jms.server.destination.QueueService"
     name="jboss.messaging.destination:service=Queue,name=ReceiverQueue"
     xmbean-dd="xmdesc/Queue-xmbean.xml">
     <depends optional-attribute-name="ServerPeer">jboss.messaging:service=ServerPeer</depends>
     <depends>jboss.messaging:service=PostOffice</depends>
   </mbean>

Answer 1

From your Spring example URL you forgot:

<!-- and this is the message listener container -->
<bean id="jmsContainer" class="org.springframework.jms.listener.DefaultMessageListenerContainer">
    <property name="connectionFactory" ref="connectionFactory"/>
    <property name="destination" ref="destination"/>
    <property name="messageListener" ref="messageListener" />
</bean>

Which connects the queue to the listener :)

EDIT

You wrote in the comments:

but still I'm getting this error : org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sender' defined in ServletContext resource [/WEB-INF/conf/applicationContext.xml]: Invocation of init method failed; nested exception is java.lang.NullPointerException

and

How does Example listener knows which queue to listen to anyways, I didn't specify to it, didn't know how

The first problem is I think a nullPointerException on the line jmsTemplate.convertAndSend . Your jmsTemplate has not been initialized.

I believe that is because the init-method is not convertAndSend. You should not need an init-method at all. You should set the properties in the applicationcontext.xml, about so:

<bean id="sender" class="quartz.spring.com.example.JmsQueueSender"> 
  <property name="queue" value="theNameOfYourQueue"> <!-- or in stead of value ref to a String which contains the shared queue name -->
  <property name="connectionFactory" ref="connectionFactory"/>
</bean>

That should fix the errors while sending (BTW why do you use JMSTemplate102 and not JMSTemplate?).

The other question, you configure the queue names by setting properties on the beans. In this case you seem to be listening to the queueDestination queue/ReceiverQueue as your jmsContainer is configured to handle calls on that queue by your listener.

Where the heck did is the messageListener bean defined in the applicationcontext.xml?

if you use ref="someName" somewhere there should also be a <bean name="someName" somewhere.

EDIT

also have a look at this example which seems to have a bit more configuration code explained. the pubSubDomain is false means it's point-to-point :)