JMS一个小例子

JMS是一个由AS提供的Message服务。它能接受消息产生者(Message Provider)所发出的消息，并把消息转发给消息消费者(Message Consumer)。

2、JMS提供2种类型的消息服务：(1)Queue，即点对点，每个消息只转发给一个消息消费者使用。(2)Topic，即发布和订阅，每个消息可以转发给所有的订阅者(消费者)。

3、WEBLOGIC 8下的JMS配置：

(1)配置JMS Connection Factory

(2)配置JMS File Store(目前所找到的文档都是配置File Store,其实在具体的应用中，可能JMS JDBC Store更广泛，但暂时没有找到资料)

(3)配置JMS Server

(4)在JMS Server的destinations中配置JMS Queue或者JMS Topic

其中提供给消息产生者和消息消费者使用的是JMS Connection Factory的JNDI和JMS Queue或者JMS Topic的JNDI。

4、消息产生者向JMS发送消息的步骤：

(1)使用JNDI查询对象JMS ConnectionFactory和Destination(JMS Queue/Topic)

(2)使用管理对象JMS ConnectionFactory建立连接Connection

(3)使用连接Connection 建立会话Session

(4)使用会话Session和管理对象Destination创建消息生产者MessageSender

(5)使用消息生产者MessageSender发送消息

一个消息发送者的例子：

Java代码

package myjms;

import java.util.*;

import javax.naming.*;

import javax.jms.*;

public class MessageProducter {

public static void main(String[] args) {

String queueConnectionFactoryName = "myjmsconnectionfactory"; //JMS Connection Factory的JNDI

String queueName = "myjmsqueue"; //JMS Queue或者JMS Topic的JNDI

boolean transacted = false;//transaction模式

int acknowledgementMode = Session.AUTO_ACKNOWLEDGE;//acknowledgement模式

String message="Message need to send";//模拟需要发送的消息

Properties properties = new Properties();

properties.put(Context.INITIAL_CONTEXT_FACTORY,"weblogic.jndi.WLInitialContextFactory");

properties.put(Context.PROVIDER_URL, "t3://localhost:7001");

try {

Context context = new InitialContext(properties);

Object obj = context.lookup(queueConnectionFactoryName);

QueueConnectionFactory queueConnectionFactory = (QueueConnectionFactory) obj;//JMS Connection Factory的获得

obj = context.lookup(queueName);

Queue queue = (Queue) obj;//JMS Queue或者JMS Topic的获得

QueueConnection queueConnection=queueConnectionFactory.createQueueConnection();//产生连接

queueConnection.start();

QueueSession queueSession = queueConnection.createQueueSession(transacted, acknowledgementMode);

TextMessage textMessage = queueSession.createTextMessage();

textMessage.clearBody();

textMessage.setText(message);

QueueSender queueSender = queueSession.createSender(queue);

queueSender.send(textMessage);

if (transacted) {

queueSession.commit();

}

if (queueSender != null) {

queueSender.close();

}

if (queueSession != null) {

queueSession.close();

}

if (queueConnection != null) {

queueConnection.close();

}

}

catch(Exception ex){

ex.printStackTrace();

}

}

}

package myjms;

import java.util.*;

import javax.naming.*;

import javax.jms.*;

public class MessageProducter {

public static void main(String[] args) {

String queueConnectionFactoryName = "myjmsconnectionfactory"; //JMS Connection Factory的JNDI

String queueName = "myjmsqueue"; //JMS Queue或者JMS Topic的JNDI

boolean transacted = false;//transaction模式

int acknowledgementMode = Session.AUTO_ACKNOWLEDGE;//acknowledgement模式

String message="Message need to send";//模拟需要发送的消息

Properties properties = new Properties();

properties.put(Context.INITIAL_CONTEXT_FACTORY,"weblogic.jndi.WLInitialContextFactory");

properties.put(Context.PROVIDER_URL, "t3://localhost:7001");

try {

Context context = new InitialContext(properties);

Object obj = context.lookup(queueConnectionFactoryName);

QueueConnectionFactory queueConnectionFactory = (QueueConnectionFactory) obj;//JMS Connection Factory的获得

obj = context.lookup(queueName);

Queue queue = (Queue) obj;//JMS Queue或者JMS Topic的获得

QueueConnection queueConnection=queueConnectionFactory.createQueueConnection();//产生连接

queueConnection.start();

QueueSession queueSession = queueConnection.createQueueSession(transacted, acknowledgementMode);

TextMessage textMessage = queueSession.createTextMessage();

textMessage.clearBody();

textMessage.setText(message);

QueueSender queueSender = queueSession.createSender(queue);

queueSender.send(textMessage);

if (transacted) {

queueSession.commit();

}

if (queueSender != null) {

queueSender.close();

}

if (queueSession != null) {

queueSession.close();

}

if (queueConnection != null) {

queueConnection.close();

}

}

catch(Exception ex){

ex.printStackTrace();

}

}

}

5、消息消费者从JMS接受消息的步骤：

(1)使用JNDI查询对象JMS ConnectionFactory和Destination(JMS Queue/Topic)

(2)使用管理对象JMS ConnectionFactory建立连接Connection

(3)使用连接Connection 建立会话Session

(4)使用会话Session和管理对象Destination创建消息消费者MessageReceiver

(5)使用消息消费者MessageReceiver接受消息，需要用setMessageListener将MessageListener接口绑定到MessageReceiver

消息消费者必须实现了MessageListener接口，需要定义onMessage事件方法。

一个消息消费者的例子：

Java代码

package myjms;

import java.util.*;

import javax.naming.*;

import javax.jms.*;

public class MessageReciever

implements MessageListener {

public void onMessage(Message message) {

if (message instanceof TextMessage) {

TextMessage textMessage = (TextMessage) message;

try {

System.out.println("Message content is:" + textMessage.getText());

}

catch (JMSException e) {

e.printStackTrace();

}

}

}

public static void main(String[] args) {

MessageReciever msgRcvr=new MessageReciever();

String queueConnectionFactoryName = "myjmsconnectionfactory";

String queueName = "myjmsqueue";

boolean transacted = false;

int acknowledgementMode = Session.AUTO_ACKNOWLEDGE;

Properties properties = new Properties();

properties.put(Context.INITIAL_CONTEXT_FACTORY,

"weblogic.jndi.WLInitialContextFactory");

properties.put(Context.PROVIDER_URL, "t3://localhost:7001");

try {

Context context = new InitialContext(properties);

Object obj = context.lookup(queueConnectionFactoryName);

QueueConnectionFactory queueConnectionFactory = (QueueConnectionFactory)

obj;

obj = context.lookup(queueName);

Queue queue = (Queue) obj;

QueueConnection queueConnection = queueConnectionFactory.

createQueueConnection();

queueConnection.start();

QueueSession queueSession = queueConnection.createQueueSession(transacted,

acknowledgementMode);

QueueReceiver queueReceiver = queueSession.createReceiver(queue);

queueReceiver.setMessageListener(msgRcvr);

synchronized(msgRcvr){

msgRcvr.wait(100000);

}

if (queueReceiver != null) {

queueReceiver.close();

}

if (queueSession != null) {

queueSession.close();

}

if (queueConnection != null) {

queueConnection.close();

}

}

catch (Exception ex) {

ex.printStackTrace();

}

}

}

package myjms;

import java.util.*;

import javax.naming.*;

import javax.jms.*;

public class MessageReciever

implements MessageListener {

public void onMessage(Message message) {

if (message instanceof TextMessage) {

TextMessage textMessage = (TextMessage) message;

try {

System.out.println("Message content is:" + textMessage.getText());

}

catch (JMSException e) {

e.printStackTrace();

}

}

}

public static void main(String[] args) {

MessageReciever msgRcvr=new MessageReciever();

String queueConnectionFactoryName = "myjmsconnectionfactory";

String queueName = "myjmsqueue";

boolean transacted = false;

int acknowledgementMode = Session.AUTO_ACKNOWLEDGE;

Properties properties = new Properties();

properties.put(Context.INITIAL_CONTEXT_FACTORY,

"weblogic.jndi.WLInitialContextFactory");

properties.put(Context.PROVIDER_URL, "t3://localhost:7001");

try {

Context context = new InitialContext(properties);

Object obj = context.lookup(queueConnectionFactoryName);

QueueConnectionFactory queueConnectionFactory = (QueueConnectionFactory)

obj;

obj = context.lookup(queueName);

Queue queue = (Queue) obj;

QueueConnection queueConnection = queueConnectionFactory.

createQueueConnection();

queueConnection.start();

QueueSession queueSession = queueConnection.createQueueSession(transacted,

acknowledgementMode);

QueueReceiver queueReceiver = queueSession.createReceiver(queue);

queueReceiver.setMessageListener(msgRcvr);

synchronized(msgRcvr){

msgRcvr.wait(100000);

}

if (queueReceiver != null) {

queueReceiver.close();

}

if (queueSession != null) {

queueSession.close();

}

if (queueConnection != null) {

queueConnection.close();

}

}

catch (Exception ex) {

ex.printStackTrace();

}

}

}

6、Message-driven Bean

MDB实际上就是一个消息消费者的客户端程序。它由AS EJB Container来管理。在JBUILDER生成一个MDB非常简单。