EJB中有三种Bean,EntityBean，SessionBean，MessageBean，其中MessageBean就是用来发送消息的。
服务器：JBoss 4.2
EJB中支持两种类型的消息，一种是Topic，一种是Queue。
Topic：基于发布/订阅的方式，允许有多个接受者，消息生产者将消息发送到主题上，接受者必须先订阅该主题。
Queue：点对点的方式，只能被一个接受者接受一次，消息生产者把消息发送到队列中，不需订阅。
要在JBoss中使用JMS，需要配置一些文件
1.%JBOSS_HOME%\server\default\deploy 下mail-service.xml,该文件用于配置发送email的一些参数（例子中使用gmail服务器）
<?xml version="1.0" encoding="UTF-8"?>
<server>
<mbean code="org.jboss.mail.MailService"
name="jboss:service=Mail">
<attribute name="JNDIName">java:/Mail</attribute>
<attribute name="User">zoucailong</attribute>
<attribute name="Password">******</attribute>
<attribute name="Configuration">
<!-- A test configuration -->
<configuration>
<!-- Change to your mail server prototocol -->
<property name="mail.store.protocol" value="pop3"/>
<property name="mail.transport.protocol" value="smtp"/>
<!-- Change to the user who will receive mail -->
<property name="mail.user" value="zoucailong"/>
<!-- Change to the mail server -->
<property name="mail.pop3.host" value="pop3.gmail.com"/>
<!-- Change to the SMTP gateway server -->
<property name="mail.smtp.host" value="smtp.gmail.com"/>
<property name="mail.smtp.socketFactory.class" value="javax.net.ssl.SSLSocketFactory"/>
<property name="mail.smtp.socketFactory.fallback" value="false"/>
<property name="mail.smtp.auth" value="true"/>
<!-- The mail server port -->
<property name="mail.smtp.port" value="465"/>
<!-- Change to the address mail will be from -->
<property name="mail.from" value="zoucailong@gmail.com"/>
<!-- Enable debugging output from the javamail classes -->
<property name="mail.debug" value="false"/>
</configuration>
</attribute>
<depends>jboss:service=Naming</depends>
</mbean>
</server>如果邮件发送不成功，可以把"mail.debug"的值改为true调试。
2.%JBOSS_HOME%\server\default\deploy\jms 下jbossmq-destinations-service.xml，该文件用于配置Topic和Queue
<mbean code="org.jboss.mq.server.jmx.Topic"
name="jboss.mq.destination:service=Topic,name=testTopic">
<depends optional-attribute-name="DestinationManager">jboss.mq:service=DestinationManager</depends>
<depends optional-attribute-name="SecurityManager">jboss.mq:service=SecurityManager</depends>
<attribute name="SecurityConf">
<security>
<role name="guest" read="true" write="true"/>
<role name="publisher" read="true" write="true" create="false"/>
<role name="durpublisher" read="true" write="true" create="true"/>
</security>
</attribute>
</mbean>
<mbean code="org.jboss.mq.server.jmx.Queue"
name="jboss.mq.destination:service=Queue,name=fmQueue">
<depends optional-attribute-name="DestinationManager">jboss.mq:service=DestinationManager</depends>
<depends optional-attribute-name="SecurityManager">jboss.mq:service=SecurityManager</depends>
<attribute name="MessageCounterHistoryDayLimit">-1</attribute>
<attribute name="SecurityConf">
<security>
<role name="guest" read="true" write="true"/>
<role name="publisher" read="true" write="true" create="false"/>
<role name="noacc" read="false" write="false" create="false"/>
</security>
</attribute>
</mbean>启动JBoss，可以在控制台看到自己配置的Topic或Queue的名字。
定义一个实体，用来封装发送邮件所需要的参数，包括接收人邮件地址、主题、内容、附件地址等。
import java.io.Serializable;
import java.util.Date;
public class EmailEntity implements Serializable {
private static final long serialVersionUID = 3436776941158302904L;
private String from;
private String to;
private String subject;
private String content;
private String multiPartFile;
private Date sendDate;
public EmailEntity() {
}
public EmailEntity(String to, String subject, String content, String multiPartFile) {
this.to = to;
this.subject = subject;
this.content = content;
this.multiPartFile = multiPartFile;
}
public String getFrom() {
return from;
}
public void setFrom(String from) {
this.from = from;
}
public String getTo() {
return to;
}
public void setTo(String to) {
this.to = to;
}
public String getSubject() {
return subject;
}
public void setSubject(String subject) {
this.subject = subject;
}
public String getContent() {
return content;
}
public void setContent(String content) {
this.content = content;
}
public String getMultiPartFile() {
return multiPartFile;
}
public void setMultiPartFile(String multiPartFile) {
this.multiPartFile = multiPartFile;
}
public Date getSendDate() {
return sendDate;
}
public void setSendDate(Date sendDate) {
this.sendDate = sendDate;
}
}
写一个Message Producer,一个普通的Java类，在这个类中使用到JMS的API
import java.util.Properties;
import javax.jms.JMSException;
import javax.jms.MessageProducer;
import javax.jms.ObjectMessage;
import javax.jms.Queue;
import javax.jms.QueueConnection;
import javax.jms.QueueConnectionFactory;
import javax.jms.QueueSession;
import javax.jms.Session;
import javax.naming.Context;
import javax.naming.InitialContext;
import javax.naming.NamingException;
import org.apache.log4j.Logger;
public class MsgProducerService {
private static Logger logger = Logger.getLogger(MsgProducerService.class);
private static InitialContext context;
private static Queue queue;
private static QueueConnectionFactory connectionFactory;
private static InitialContext getInitialContext() throws NamingException {
if(context == null) {
Properties env = new Properties();
env.setProperty(Context.INITIAL_CONTEXT_FACTORY, "org.jnp.interfaces.NamingContextFactory");
env.setProperty(Context.PROVIDER_URL, "localhost");
context = new InitialContext(env);
}
return context;
}
static {
try {
connectionFactory = (QueueConnectionFactory) getInitialContext().lookup("ConnectionFactory");
queue = (Queue) getInitialContext().lookup("queue/fmQueue");
} catch (NamingException e) {
e.printStackTrace();
}
}
public static void sendMail(EmailEntity emailEntity) {
QueueConnection connection = null;
QueueSession session = null;
MessageProducer producer;
try {
connection = connectionFactory.createQueueConnection();
session = connection.createQueueSession(false, Session.AUTO_ACKNOWLEDGE);
producer = session.createProducer(queue);
ObjectMessage msg = session.createObjectMessage();
msg.setObject(emailEntity);
producer.send(msg);
} catch (JMSException e) {
logger.error("Send email error:"+e);
e.printStackTrace();
} finally {
try {
if(session != null)
session.close();
if(connection != null)
connection.close();
} catch (JMSException e) {
e.printStackTrace();
}
}
}
}以上代码中，ObjectMessage根据你的消息类型而定，有
StreamMessage：一种主体中包含Java基本值流的消息。其填充和读取均按顺序进行。
MapMessage：一种主体中包含一组名-值对的消息。(没有定义条目顺序)
TextMessage：一种主体中包含Java字符串的消息(例如：XML消息)
ObjectMessage：一种主体中包含序列化Java对象的消息。
BytesMessage：一种主体中包含连续字节流的消息。
下面定义一个消息接受者，该类实现MessageListener接口，自动监听消息的状态，当有消息到达时，就会触发onMessage方法
import java.io.File;
import java.util.Date;
import javax.activation.DataHandler;
import javax.activation.FileDataSource;
import javax.ejb.ActivationConfigProperty;
import javax.ejb.MessageDriven;
import javax.jms.MessageListener;
import javax.jms.ObjectMessage;
import javax.mail.Message;
import javax.mail.Multipart;
import javax.mail.Session;
import javax.mail.Transport;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeBodyPart;
import javax.mail.internet.MimeMessage;
import javax.mail.internet.MimeMultipart;
import javax.naming.Context;
import javax.naming.InitialContext;
//指定destination的类型和名字，以下用的是Queue，用到上面的配置文件中定义的fmQueue
@MessageDriven(activationConfig ={
@ActivationConfigProperty(propertyName = "destinationType",
propertyValue = "javax.jms.Queue"),
@ActivationConfigProperty(propertyName = "destination",
propertyValue = "queue/fmQueue")
})
public class EmailBean implements MessageListener {
@Override
public void onMessage(javax.jms.Message msg) {
try {
if(msg != null && msg instanceof ObjectMessage) {
ObjectMessage objMsg = (ObjectMessage)msg;
EmailEntity emailEntity = (EmailEntity) objMsg.getObject();
sendMail(emailEntity);
}
} catch (Exception e) {
e.printStackTrace();
}
}
//发送邮件的方法
private void sendMail(EmailEntity emailEntity) throws Exception {
if(emailEntity == null)
return;
Context context = new InitialContext();
Session session = (Session) context.lookup("java:/Mail");
MimeMessage msg = new MimeMessage(session);
msg.setFrom();
if(emailEntity.getTo() != null && emailEntity.getTo().trim().length() > 0) {
String[] toArr = emailEntity.getTo().split(",");
if(toArr.length > 0) {
InternetAddress[] addressArr = new InternetAddress[toArr.length];
for(int i = 0; i < toArr.length; i++) {
addressArr[i] = new InternetAddress(toArr[i]);
}
msg.addRecipients(Message.RecipientType.TO, addressArr);
}
}
if(emailEntity.getSubject() != null)
msg.setSubject(emailEntity.getSubject(), "UTF-8");
if(emailEntity.getMultiPartFile() != null) {
File file = new File(emailEntity.getMultiPartFile());
if(file.exists()) {
//添加附件
Multipart multipart = new MimeMultipart();
MimeBodyPart bodyPart = new MimeBodyPart();
FileDataSource fds = new FileDataSource(emailEntity.getMultiPartFile());
bodyPart.setDataHandler(new DataHandler(fds));
bodyPart.setFileName(fds.getName());
multipart.addBodyPart(bodyPart);
if(emailEntity.getContent() != null) {
MimeBodyPart bodyPartText = new MimeBodyPart();
bodyPartText.setText(emailEntity.getContent(), "UTF-8");
multipart.addBodyPart(bodyPartText);
}
msg.setContent(multipart);
} else
return;
}
msg.setSentDate(new Date());
msg.saveChanges();
Transport.send(msg, msg.getRecipients(Message.RecipientType.TO));
}
}这样就可以实现邮件的异步发送了。