今天下午突发奇想，复习了这么多天Java，用Java发送邮件怎么样？于是查了一下资料，把工具弄出来了。
在使用时需要导入JavaMail

工具类

package cn.limexc.mail;

import com.sun.mail.util.MailSSLSocketFactory;

import javax.mail.*;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeMessage;
import java.security.GeneralSecurityException;
import java.util.Properties;

/**
 *
 * @author LIMEXC
 * @version V1.0.0
 * @createDate 2020/12/15 19:38
 * @since jdk1.8.0
 */
public class MailTool {
    String toMail;
    String subject;
    String text;
    String host = "mail.limexc.top";
    String sendUser = "test@limexc.top";
    String password ="此处密码";

    public MailTool(String toMail, String subject, String text) {
        this.toMail = toMail;
        this.subject = subject;
        this.text = text;
    }


    private Session getSysInfo(){
        // 获取系统属性
        Properties sysInfo = System.getProperties();
        // 设置邮件服务器
        sysInfo.setProperty("mail.smtp.host", host);
        sysInfo.put("mail.smtp.auth", "true");
//        // 关于QQ邮箱，还要设置SSL加密，加上以下代码即可
//        MailSSLSocketFactory qq_ssl = null;
//        try {
//            qq_ssl = new MailSSLSocketFactory();
//        } catch (GeneralSecurityException e) {
//            e.printStackTrace();
//        }
//        qq_ssl.setTrustAllHosts(true);
//        sysInfo.put("mail.smtp.ssl.enable", "true");
//        sysInfo.put("mail.smtp.ssl.socketFactory", qq_ssl);
        // 获取默认session对象
        Session session = Session.getDefaultInstance(sysInfo,new Authenticator(){
            public PasswordAuthentication getPasswordAuthentication()
            {//发件人邮件用户名、授权码
                return new PasswordAuthentication(sendUser, password);
            }
        });
        return session;
    }

    public boolean sendMail(){
        try{
            // 创建默认的 MimeMessage 对象
            MimeMessage message = new MimeMessage(getSysInfo());
            // Set From: 头部头字段
            message.setFrom(new InternetAddress(sendUser));
            // Set To: 头部头字段
            message.addRecipient(Message.RecipientType.TO, new InternetAddress(toMail));
            // Set Subject: 头部头字段
            message.setSubject(subject);
            // 设置消息体
            message.setText(text);
            // 发送消息
            Transport.send(message);
            System.out.println("Sent message successfully....");
            return true;
        }catch (MessagingException mex) {
            mex.printStackTrace();
            return false;
        }
    }
}

使用方法

package cn.limexc.mail;

/**
 * @author LIMEXC
 * @CreateDate 2020/12/15 19:46
 * @since jdk1.8.0
 */
public class Test {
    public static void main(String[] args) {
        MailTool aa = new MailTool("########@qq.com","Hello","封装完成");
        aa.sendMail();
    }
}

测试截图