Spring的JavaMail实现异步发送邮件

具体背景就不说了，可以网上搜索相关知识，或者直接看Sping MailSender的官坊网页。这里就直接实战了（Java实现异步发送电子邮件，包含中文无乱码）。

Maven：

    <dependency>
      <groupId>com.sun.mail</groupId>
      <artifactId>javax.mail</artifactId>
      <version>1.5.0</version>
    </dependency>

ApplicationContext.xml：

    <!-- SET default mail properties -->
    <bean id="mailSender" class="org.springframework.mail.javamail.JavaMailSenderImpl">
        <property name="host" value="smtp.sina.com"/>
        <property name="protocol" value="smtp" />
        <!-- 465 for Gamil -->
        <property name="port" value="25"/>
        <property name="username" value="xxx@sina.com"/>
        <property name="password" value="xxx"/>
        <property name="javaMailProperties">
            <props>
                <prop key="mail.transport.protocol">smtp</prop>
                <prop key="mail.smtp.auth">true</prop>
                <!-- true for Gamil -->
                <prop key="mail.smtp.starttls.enable">false</prop>
                <prop key="mail.debug">true</prop>
            </props>
        </property>
    </bean>

    <!--Asyn send Eamil-->
    <bean id="taskExecutor" class="org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor">
       <property name="corePoolSize" value="10"/>
       <property name="maxPoolSize" value="30"/>
    </bean>

    <!-- You can have some pre-configured messagess also which are ready to send -->
    <bean id="preConfiguredMessage" class="org.springframework.mail.SimpleMailMessage">
        <property name="to" value="xxx@gmail.com"></property>
        <property name="from" value="xxx@sina.com"></property>
        <property name="subject" value="Test email from sina."/>
    </bean>

Email实体类：

package com.xxx;

import java.io.Serializable;

/**
 * @author
 *
 */
public class ApplicationEmail implements Serializable {  

    public String getAddressee() {
        return addressee;
    }
    public void setAddressee(String addressee) {
        this.addressee = addressee;
    }
    public String getCc() {
        return cc;
    }
    public void setCc(String cc) {
        this.cc = cc;
    }
    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;
    }

    /**收件人**/
    private String addressee;
     /**抄送给**/
    private String cc;
     /**邮件主题**/
    private String subject;
      /**邮件内容**/
    private String content;
     /**附件**/
    //private MultipartFile[] attachment = new MultipartFile[0];    

}  

异步邮件发送封装类：

package com.xxx;

import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.util.Properties;
import javax.mail.MessagingException;
import javax.mail.Session;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeMessage;
import javax.mail.internet.MimeUtility;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.springframework.core.task.TaskExecutor;
import org.springframework.mail.SimpleMailMessage;
import org.springframework.mail.javamail.JavaMailSender;
import org.springframework.mail.javamail.MimeMessageHelper;
import org.springframework.stereotype.Service;

import com.xxx.Mailer;

/**
 * @author
 *
 */
@Service
public class ApplicationMailer implements Mailer
{
    @Autowired
    private JavaMailSender mailSender;

    @Autowired
    private TaskExecutor taskExecutor;

    @Autowired
    private SimpleMailMessage preConfiguredMessage;

    /**
     * 同步发送邮件
     *
     * @param email
     * @throws MessagingException
     * @throws IOException
     */
    public void sendMailBySynchronizationMode(ApplicationEmail email) throws MessagingException, IOException {
         Session session=Session.getDefaultInstance(new Properties());
         MimeMessage mime= new MimeMessage(session);
         MimeMessageHelper helper = new MimeMessageHelper(mime, true, "utf-8");
         helper.setFrom("xxx@sina.com");//发件人
         helper.setTo(InternetAddress.parse(email.getAddressee()));//收件人
         //helper.setBcc("administrator@chinaptp.com");//暗送
         helper.setReplyTo("xxx@sina.com");//回复到
         helper.setSubject(email.getSubject());//邮件主题
         helper.setText(email.getContent(), true);//true表示设定html格式  

         mailSender.send(mime);
    }

    /**
     * 异步发送邮件
     *
     * @param email
     */
    public void sendMailByAsynchronousMode(final ApplicationEmail email){  taskExecutor.execute(new Runnable(){
         public void run(){
        try {
              sendMailBySynchronizationMode(email);
             } catch (Exception e) {
            }
         }
      });
    }
}

public interface Mailer {
    public void sendMailByAsynchronousMode(final ApplicationEmail email);
}

调用Service异步发送邮件：

  @Autowired
  private Mailer mailer;

   //这是要异步发送邮件
   ApplicationEmail email = new ApplicationEmail();
   email.setAddressee("xxx@gmail.com");
   email.setSubject("测试邮件有一份");
   email.setContent("这个是内容html内容");
   mailer.sendMailByAsynchronousMode(email);

这里实现异步使用的是Task Execution，也可以用异步注解@Async，或者JMS（需要J2EE环境）；如果需要调度可以用Quartz（使用场景如：每天2:00需要批量给会员发邮件）

如果要实现高可靠的高并发的异步邮件发送，可以用JMS或Queue，参考。

本文结束。（干货分享：Spring和JavaMail发送邮件的经验.pdf）