java Mail如何发送邮件

1.应用场景：在系统需要发送与用户相关的消息时，而用户不在线，可以采取发送邮件的方式，使用户了解最新的系统情况 或者发送验证码等验证场景

2.实验环境 主要使用mail.jar和activation.jar两个包

3.使用一份简单的邮件

public void sendMail() throws AddressException, MessagingException{
        /*
         * 1.得到session
         */
        
        Properties properties=new Properties();
        properties.setProperty("mail.host", "smtp.163.com");
        properties.setProperty("mail.smtp.auth", "true");
        
        //账户信息测试
        Authenticator auth =new Authenticator() {

            @Override
            protected PasswordAuthentication getPasswordAuthentication() {
                return new PasswordAuthentication("zhou_s1", "xxx");
//这里是账户名和密码
            }
        };
        
        Session session =Session.getInstance(properties,auth);
        /*
         * 2.创建消息message
         */
        MimeMessage message=new MimeMessage(session);
        
        message.setFrom(new InternetAddress("[email protected]"));//设置发件人
        message.setRecipients(RecipientType.TO, "[email protected]");//设置收件人
        //message.setRecipients(RecipientType.CC, "[email protected]");//设置抄送
        //message.setRecipients(RecipientType.BCC, "[email protected]");//暗送给谁
        
        message.setSubject("这一份来自周松测试的垃圾邮件--javamail");
        message.setContent("test test test !!!","text/html;charset=utf-8");
        
        /*
         * 3.发送
         */
        Transport.send(message);
    }

4.一份带有附件的邮件

public void sendMailMore() throws AddressException, MessagingException, IOException{
        /*
         * 1.得到session
         */
        
        Properties properties=new Properties();
        properties.setProperty("mail.host", "smtp.163.com");
        properties.setProperty("mail.smtp.auth", "true");
        
        //账户信息测试
        Authenticator auth =new Authenticator() {

            @Override
            protected PasswordAuthentication getPasswordAuthentication() {
                return new PasswordAuthentication("zhou_s1", "xxx");
            }
        };
        
        Session session =Session.getInstance(properties,auth);
        
        
        /*
         * 2.创建消息message
         */
        MimeMessage message=new MimeMessage(session);
        
        message.setFrom(new InternetAddress("[email protected]"));//设置发件人
        message.setRecipients(RecipientType.TO, "[email protected]");//设置收件人
        
        message.setSubject("这是一份含有附件的邮件---测试使用--javamail");
        
        /******************************************************/
        /*
         * 附件的主体流程 附件含有多个组成部分 简称多部件
         *  
         */
        MimeMultipart list =new MimeMultipart();
        
        //1.邮件主要内容  MimeBodyPart
        MimeBodyPart part1 =new MimeBodyPart();
        
        //1.1.内容
        part1.setContent("一份含有附件的测试邮件", "text/html;charset=utf-8");
        
        //1.2将主体添加到邮件中去
        list.addBodyPart(part1);
        
        //2.1.邮件附件里面的内容
        MimeBodyPart part2 =new MimeBodyPart();
                
        //2.2.附件
        File file =new File("G:/JAVAtest/Merge.mp3");
        
        part2.attachFile(file);
        part2.setFileName(MimeUtility.encodeText("Merge.mp3"));
        //2.3将主体添加到邮件中去
        list.addBodyPart(part2);    
        
        //3.最后将多部件添加到消息中去
        message.setContent(list);
        
        //发送
        Transport.send(message);
    }

测试完毕！