springboot实现邮件发送并支持附件教程

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

#企业微信发邮件配置
mail:
  transport:
    protocol: ssl
  smtp:
    host: smtp.exmail.qq.com # 企业微信的host
    port: 465 #邮件服务器的端口号
    auth: true
    ssl:
      enable: true
    from: xxxxx  # 发送邮件
  enable: true
  account: xxxxx # 用于身份验证的邮箱地址
  password: xxxxx #用于身份验证的邮箱地址 密码

package com.gotion.framework.email;
import java.util.List;
/**
 * 邮件发送Service
 * @Description
 * @Author
 **/
public interface ISendEmailService {
    /**
     * 发送邮件
     * @param fromAliasName 别名
     * @param to 发送目标
     * @param subject 主题
     * @param content 内容
     * @param attachFileList 附件
     */
    void send(String fromAliasName,String to,String subject,String content, List<String> attachFileList);
}

package com.gotion.framework.email.impl;
import com.baomidou.mybatisplus.core.toolkit.CollectionUtils;
import com.gotion.framework.email.ISendEmailService;
import com.sun.mail.util.MailSSLSocketFactory;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
import org.springframework.scheduling.annotation.Async;
import org.springframework.stereotype.Service;
import javax.mail.Authenticator;
import javax.mail.Message;
import javax.mail.Multipart;
import javax.mail.PasswordAuthentication;
import javax.mail.Session;
import javax.mail.Transport;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeBodyPart;
import javax.mail.internet.MimeMessage;
import javax.mail.internet.MimeMultipart;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.security.GeneralSecurityException;
import java.util.Date;
import java.util.List;
import java.util.Properties;
/**
 * 邮件发送工具类
 * 注：腾讯企业微信邮箱需要用SSL方式发送
 * @author
 */
@Slf4j
@Service
@ConditionalOnProperty("mail")
public class SendEmailServiceImpl implements ISendEmailService {
    @Value("${mail.account}")
    private  String account ;
    /**
     * 登录密码
     */
    @Value("${mail.password}")
    private  String password;
    /**
     * 发信协议
     */
    @Value("${mail.transport.protocol}")
    private String protocol;
    /**
     * 邮件服务器地址
     */
    @Value("${mail.smtp.host}")
    private String host;
    /**
     * 邮件发送方
     */
    @Value("${mail.smtp.from}")
    private String from;
    /**
     * 发信端口
     */
    @Value("${mail.smtp.port}")
    private String port ;
    /**
     * 发信端口
     */
    @Value("${mail.smtp.auth}")
    private String auth ;
    @Value("${mail.smtp.ssl.enable}")
    private String sslEnable ;
    /**
     * 发送邮件
     */
    @Override
    @Async
    public void send(String fromAliasName, String to, String subject, String content, List<String> attachFileList) {
        // 设置邮件属性
        Properties prop = new Properties();
        prop.setProperty("mail.transport.protocol", protocol);
        prop.setProperty("mail.smtp.host", host);
        prop.setProperty("mail.smtp.port", port);
        prop.setProperty("mail.smtp.auth", auth);
        prop.setProperty("mail.smtp.ssl.protocols", "TLSv1.2");
        prop.setProperty("mail.smtp.from", from);
        MailSSLSocketFactory sslSocketFactory = null;
        try {
            sslSocketFactory = new MailSSLSocketFactory();
            sslSocketFactory.setTrustAllHosts(true);
        } catch (GeneralSecurityException e) {
            log.error("MailSSLSocketFactory set fail",e);
        }
        if (sslSocketFactory == null) {
            log.error("Failed to enable MailSSLSocketFactory");
        } else {
            prop.put("mail.smtp.ssl.enable",sslEnable);
            prop.put("mail.smtp.ssl.socketFactory", sslSocketFactory);
            // 创建邮件会话（注意，如果要在一个进程中切换多个邮箱账号发信，应该用 Session.getInstance）
            Session session = Session.getDefaultInstance(prop, new MyAuthenticator(account, password));
            try {
                MimeMessage mimeMessage = new MimeMessage(session);
                // 设置发件人别名（如果未设置别名就默认为发件人邮箱）
                if (fromAliasName != null && !fromAliasName.trim().isEmpty()) {
                    mimeMessage.setFrom(new InternetAddress(account, fromAliasName));
                }
                // 设置主题和收件人、发信时间等信息
                mimeMessage.addRecipient(Message.RecipientType.TO, new InternetAddress(to));
                mimeMessage.setSubject(subject);
                mimeMessage.setSentDate(new Date());
                // 如果有附件信息，则添加附件
                Multipart multipart = new MimeMultipart();
                MimeBodyPart body = new MimeBodyPart();
                body.setContent(content, "text/html; charset=UTF-8");
                multipart.addBodyPart(body);
                // 添加所有附件（添加时判断文件是否存在）
                if (CollectionUtils.isNotEmpty(attachFileList)){
                    for(String filePath : attachFileList){
                        if(Files.exists(Paths.get(filePath))){
                            MimeBodyPart tempBodyPart = new MimeBodyPart();
                            tempBodyPart.attachFile(filePath);
                            multipart.addBodyPart(tempBodyPart);
                        }
                    }
                }
                mimeMessage.setContent(multipart);
                // 开始发信
                mimeMessage.saveChanges();
                Transport.send(mimeMessage);
            }catch (Exception e) {
                log.error("Fail to send email",e);
            }
        }
    }
    /**
     * 认证信息
     */
    static class MyAuthenticator extends Authenticator {
        /**
         * 用户名
         */
        String username = null;
        /**
         * 密码
         */
        String password = null;
        /**
         * 构造器
         *
         * @param username 用户名
         * @param password 密码
         */
        public MyAuthenticator(String username, String password) {
            this.username = username;
            this.password = password;
        }
        @Override
        protected PasswordAuthentication getPasswordAuthentication() {
            return new PasswordAuthentication(username, password);
        }
    }
}

package com.gotion;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration;
import org.springframework.scheduling.annotation.EnableAsync;

/**
 * 启动程序
 *
 */
@EnableAsync
@SpringBootApplication(exclude = { DataSourceAutoConfiguration.class })
public class GotionApplication
{
    public static void main(String[] args)
    {
        SpringApplication.run(GotionApplication.class, args);
    }
}

import java.util.List;

@RestController
@Slf4j
public class TestEmailSendController {

	@Autowired(required = false)
	private ISendEmailService sendEmailService;

	@PostMapping("/example/send/email")
	public AjaxResult testSendEmail(@RequestParam(required = false) String fromAliasName,
									@RequestParam(required = false) String to,
									@RequestParam(required = false) String subject,
									@RequestParam(required = false) String content,
									@RequestParam(required = false) String attachFiles) {
		List<String> attachFileList = Arrays.stream(attachFiles.split(",")).toList();
		sendEmailService.send(fromAliasName,to,subject,content,attachFileList);
		return AjaxResult.success();
	}
}