一、开通Google的SMTP协议

• 在谷歌邮箱中开启IMAP访问

•  到google的设置中开启两步验证功能

• 在到 创建和管理应用专用密码

二、java中实现 

• 引入maven 

        <!--邮件--><dependency><groupId>com.sun.mail</groupId><artifactId>javax.mail</artifactId><version>1.6.2</version></dependency>

•  工具类

import javax.activation.DataHandler;
import javax.mail.*;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeBodyPart;
import javax.mail.internet.MimeMessage;
import javax.mail.internet.MimeMultipart;
import javax.mail.util.ByteArrayDataSource;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.util.Properties;/*** @author LKX* @version 1.0* @Description* @date 2025-06-11 14:10*/
public class MailUtils {public static String USERNAME = "kexianglin261@gmail.com"; //	邮箱发送账号public static String PASSWORD = "hrnj tyoi mnie rodo"; //邮箱平台的授权码public static String HOST = "smtp.gmail.com"; // SMTP服务器地址public static String PORT = "587"; //SMTP服务器端口public static Session session = null;/*** 创建Sesssion*/public static void createSession() {if (session != null) return;Properties props = new Properties();props.put("mail.smtp.auth", "true");props.put("mail.smtp.starttls.enable", "true");props.put("mail.smtp.host", HOST); //SMTP主机名props.put("mail.smtp.port", PORT);session = Session.getInstance(props,new javax.mail.Authenticator() {protected PasswordAuthentication getPasswordAuthentication() {return new PasswordAuthentication(USERNAME, PASSWORD);}});}/*** 发送纯文本邮件，单人发送** @param title* @param content* @param toMail*/public static void postMessage(String title, String content, String toMail) {try {createSession();//构造邮件主体MimeMessage message = new MimeMessage(session);message.setSubject(title);message.setText(content);message.setFrom(new InternetAddress(USERNAME));message.setRecipient(MimeMessage.RecipientType.TO, new InternetAddress(toMail));//发送Transport.send(message);} catch (MessagingException e) {throw new RuntimeException(e);}}/*** 发送带附件的邮件** @param title* @param content* @param fileName* @param filePath* @param toMail*/public void postMessageWithFile(String title, String content, String fileName, String filePath, String toMail) {try {createSession();//构造邮件主体MimeMessage message = new MimeMessage(session);message.setSubject(title);//邮件主体BodyPart textPart = new MimeBodyPart();textPart.setContent(content, "text/html;charset=utf-8");//邮件附件BodyPart filePart = new MimeBodyPart();filePart.setFileName(fileName);filePart.setDataHandler(new DataHandler(new ByteArrayDataSource(Files.readAllBytes(Paths.get(filePath)), "application/octet-stream")));Multipart multipart = new MimeMultipart();multipart.addBodyPart(textPart);multipart.addBodyPart(filePart);message.setContent(multipart);message.setFrom(new InternetAddress(USERNAME));message.setRecipient(MimeMessage.RecipientType.TO, new InternetAddress(toMail));//发送Transport.send(message);} catch (Exception e) {throw new RuntimeException(e);}}
}