利用JavaMail怎么实现一个邮件发送功能

@Test
 public void sendMail() throws Exception{
  //1,声明properties对象放信息
  Properties props = new Properties();
  //设置连接哪一台服务器
  props.setProperty("mail.host", "smtp.163.com");
  //设置是否认证：
  props.setProperty("mail.smtp.auth", "true");
  
  //2，声明用户名和密码
  Authenticator auth = new Authenticator(){
   //返回用户名和密码对象
   @Override
   protected PasswordAuthentication getPasswordAuthentication() {
    PasswordAuthentication pa = new PasswordAuthentication("xxxxx@163.com", "123456");
    return pa;
   }
  };
  //3,获取session对象
  Session session = Session.getDefaultInstance(props, auth);
  //设置session为调试模式
  session.setDebug(true);
  //4,声明信息
  MimeMessage mm1 = new MimeMessage(session);
  //5,设置发件人信息
  Address form = new InternetAddress("xxxxx@163.com"); 
  mm1.setFrom(form);
  //6,设置收件人 ,RecipientType:发送，抄送，密送 类型
  mm1.setRecipient(RecipientType.TO, new InternetAddress("xxx@qq.com"));
  //mm1.setRecipient(RecipientType.CC, new InternetAddress(""));//抄送
 
  //7，设置主题
  mm1.setSubject("拉面学习通知");
  String cont = "请点击 官网新闻查看祝您发财";
  mm1.setContent(cont, "text/html;charset=UTF-8");
  
  //8，发送
  Transport.send(mm1);
 
 }

@Test
 public void sendMailWithFile() throws Exception{
 Properties ps = new Properties();
 ps.setProperty("mail.host", "smtp.163.com");
 ps.setProperty("mail.smtp.auth", "true");
 
 Authenticator auth = new Authenticator(){
  @Override
  protected PasswordAuthentication getPasswordAuthentication() {
  return new PasswordAuthentication("xxx@163.com","xxx.");
  } 
 };
 Session session = Session.getDefaultInstance(ps, auth);
 session.setDebug(true);
 MimeMessage msg = new MimeMessage(session);
 Address address = new InternetAddress("xxx@163.com");
 msg.setFrom(address);
 //发送给
 msg.setRecipient(RecipientType.TO, new InternetAddress("xxx@qq.com"));
 msg.setRecipient(RecipientType.BCC, new InternetAddress("xxx@qq.com"));//密送
 msg.setRecipient(RecipientType.CC, new InternetAddress("xxx@qq.com"));//抄送
 msg.setSubject("$激情小视频*免费观看");
 
 //声明多部件处理
 MimeMultipart mm = new MimeMultipart();
 
 MimeBodyPart body1 = new MimeBodyPart();
 //设置附件
 DataSource ds1 = new FileDataSource(new File("./img/a.jpg"));
 DataHandler dh2 = new DataHandler(ds1);
 body1.setDataHandler(dh2);
 //必须设置名称
 body1.setFileName(MimeUtility.encodeText("美女.jpg"));
 
 MimeBodyPart body2 = new MimeBodyPart();
 DataSource ds2 = new FileDataSource(new File("./img/b.jpg"));
 DataHandler dh3 = new DataHandler(ds2);
 body2.setDataHandler(dh3);
 body2.setFileName(MimeUtility.encodeText("美女2.jpg"));
 
 MimeBodyPart body3 = new MimeBodyPart();
 DataSource ds3 = new FileDataSource(new File("./img/m.mp3"));
 DataHandler dh4 = new DataHandler(ds3);
 body3.setDataHandler(dh4);
 body3.setFileName(MimeUtility.encodeText("小电影.mp3"));

 //添加body到mm
 mm.addBodyPart(body1);
 mm.addBodyPart(body2);
 mm.addBodyPart(body3);
 
 msg.setContent(mm);

 //设置发送日期
 Calendar c = Calendar.getInstance();
 c.add(Calendar.DATE, -5);
 msg.setSentDate(c.getTime());

 //发送
 Transport.send(msg);
 }