<!-- Javamail -->
    <dependency>
     <groupId>javax.mail</groupId>
     <artifactId>mail</artifactId>
     <version>1.4.4</version>
    </dependency>
    <dependency>
     <groupId>org.springframework</groupId>
     <artifactId>spring-context-support</artifactId>
     <version>4.2.4.RELEASE</version>
    </dependency>

package cn.itcast.jk.utils;
import java.util.Properties;
import javax.mail.Address;
import javax.mail.Session;
import javax.mail.Transport;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeMessage;
import javax.mail.internet.MimeMessage.RecipientType;

public class MailUtils {
  /**
   * 發(fā)送郵件
   * @throws Exception 
   * 
   */
  public static void sendMsg(String toAddress,String subject,String content) throws Exception{
    //1.設(shè)置郵件的一些信息
    Properties props = new Properties();
    //發(fā)送郵件的服務(wù)器地址
    props.put("mail.smtp.host", "smtp.163.com");//smtp.qq.com stmp.sina.com
    props.put("mail.smtp.auth", "true");
    //2.創(chuàng)建Session對象
    Session session =Session.getInstance(props);
    //3.創(chuàng)建出MimeMessage，郵件的消息對象
    MimeMessage message = new MimeMessage(session);
    //4.設(shè)置發(fā)件人
    Address fromAddr = new InternetAddress("發(fā)件人郵箱");
    message.setFrom(fromAddr);

    //5.設(shè)置收件人
    Address toAddr=new InternetAddress(toAddress);
    message.setRecipient(RecipientType.TO, toAddr);

    //6.設(shè)置郵件的主題
    message.setSubject(subject);

    //7.設(shè)置郵件的正文
    message.setText(content);
    message.saveChanges();//保存更新

    //8.得到火箭
    Transport transport = session.getTransport("smtp");

    transport.connect("smtp.163.com","發(fā)件人郵箱","發(fā)件人密碼"); //設(shè)置了火箭的發(fā)射地址

    transport.sendMessage(message, message.getAllRecipients());//發(fā)送具體內(nèi)容及接收人

    transport.close();
  }
}

mail.host=smtp.163.com
mail.username=你的郵箱名——也就是@前面的東西
mail.password=密碼
mail.from=你的郵箱地址

<?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:p="http://www.springframework.org/schema/p" 
  xmlns:context="http://www.springframework.org/schema/context"  
  xmlns:tx="http://www.springframework.org/schema/tx" 
  xmlns:aop="http://www.springframework.org/schema/aop" 
  xsi:schemaLocation="http://www.springframework.org/schema/beans  
  http://www.springframework.org/schema/beans/spring-beans.xsd  
  http://www.springframework.org/schema/aop  
  http://www.springframework.org/schema/aop/spring-aop.xsd  
  http://www.springframework.org/schema/tx  
  http://www.springframework.org/schema/tx/spring-tx.xsd  
  http://www.springframework.org/schema/context  
  http://www.springframework.org/schema/context/spring-context.xsd">

  <description>JavaMail的配置文件</description>
  <!-- 加載mail.properties配置文件 -->
  <context:property-placeholder location="classpath:mail.properties"/>


  <!-- 簡單消息對象創(chuàng)建 -->
  <bean id="mailMessage" class="org.springframework.mail.SimpleMailMessage">
     <property name="from" value="${mail.from}"></property>
  </bean>

  <!-- 2.創(chuàng)建發(fā)送器 -->  
  <bean id="mailSender" class="org.springframework.mail.javamail.JavaMailSenderImpl">
     <property name="host" value="${mail.host}"></property>
     <property name="username" value="${mail.username}"></property>
     <property name="password" value="${mail.password}"></property>
     <property name="defaultEncoding" value="UTF-8"></property>
     <property name="javaMailProperties">
      <props>
         <prop key="mail.smtp.auth">true</prop>
         <prop key="mail.debug">true</prop>
         <prop key="mail.smtp.timeout">0</prop>
      </props>
     </property>
  </bean>
</beans>

<import resource="classpath:spring/applicationContext-mail.xml"/>

<bean id="userService" class="cn.itcast.jk.service.impl.UserServiceImpl">
    <property name="baseDao" ref="baseDao"></property>
    <property name="mailMessage" ref="mailMessage"></property>
    <property name="mailSender" ref="mailSender"></property>
  </bean>

/spring整合javaMail需要注入：
  private SimpleMailMessage mailMessage;
  private JavaMailSender mailSender;

  public void setMailMessage(SimpleMailMessage mailMessage) {
    this.mailMessage = mailMessage;
  }

  public void setMailSender(JavaMailSender mailSender) {
    this.mailSender = mailSender;
  }
public void saveOrUpdate(final User entity) {    
    if(UtilFuns.isEmpty(entity.getId())){
      //判斷id是否有值

      //說明id沒有值，說明保存  
      entity.setState(1); //1代表可用
      String id = UUID.randomUUID().toString();
      entity.setId(id);
      entity.getUserinfo().setId(id);

      //設(shè)置初始密碼 需要將默認的密碼加密后保存到數(shù)據(jù)庫
      entity.setPassword(Encrypt.md5(SysConstant.DEFAULT_PASS, entity.getUserName()));
//final就是延長對象的生命周期，不然entity只能在saveOrUpdate中使用，使用完成后方法彈棧，而run方法內(nèi)就無法再使用之前定義好的entity。
//使用spring與javaMail實現(xiàn)新員工入職時郵件的發(fā)送
//使用線程并try-catch的目的就是如果郵件發(fā)送失敗，也不影響信息保存到數(shù)據(jù)庫。郵件發(fā)送成為了一個獨立的過程。
      Thread th = new Thread(new Runnable(){
        public void run(){
          try {
            mailMessage.setTo(entity.getUserinfo().getEmail());
            mailMessage.setSubject("新員工入職信息");
            mailMessage.setText("歡迎"+entity.getUserinfo().getName()+"加入廊坊思創(chuàng)志遠科技有限公司，您在公司的賬號："+entity.getUserName()+",密碼："+SysConstant.DEFAULT_PASS);
            mailSender.send(mailMessage);
          } catch (MailException e) {
            e.printStackTrace();
          }
        }
      });
      th.start();
    }
    baseDao.saveOrUpdate(entity);
  }