JavaMail实现邮箱验证码

import java.util.Arrays;
import java.util.Properties;
import java.util.Random;

import javax.mail.Address;
import javax.mail.Authenticator;
import javax.mail.Message;
import javax.mail.PasswordAuthentication;
import javax.mail.Session;
import javax.mail.Transport;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeMessage;

public class SendEmail {

    public static String send(String email) {
        Properties p = new Properties();
        p.put("mail.smtp.host", "smtp.163.com");  //smtp服务器地址，可以使用别的 
        p.put("mail.smtp.auth", "true");
        Authenticator authenticator = new Authenticator() {
            @Override
            protected PasswordAuthentication getPasswordAuthentication() {
                return new PasswordAuthentication("(您的163邮箱)","(您的邮箱密码)");
            }
        };
        //获得一个带有authenticator的session实例 
        Session sendMailSession = Session.getDefaultInstance(p,authenticator);
        Message mailMessage = new MimeMessage(sendMailSession);
        
        //产生4位验证码
        Random r = new Random();
        StringBuffer captcha1 = new StringBuffer();
        for (int i = 0; i < 4; i++) {
            captcha1.append(r.nextInt(9)+"");
        }
        String captcha = new String(captcha1);
        
        try {
            System.out.println("I‘m sending...");
            Address from = new InternetAddress("(您的163邮箱)");
             //设置发出方
            mailMessage.setFrom(from);
            Address to = new InternetAddress(email);//设置接收人员
            mailMessage.setRecipient(Message.RecipientType.TO, to);
            mailMessage.setSubject("验证码");//设置邮件标题
            mailMessage.setText(captcha); //设置邮件内容
            // 发送邮件
            Transport.send(mailMessage);
            return captcha;
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return null;
    }
    
    public static void main(String[] args) {
        SendEmail.send("123456@qq.com");
    }

}