最简单的 springboot 发送邮件,使用thymeleaf模板

1，导入需要的包

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-thymeleaf</artifactId>
        </dependency>

         <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-mail</artifactId>
        </dependency>

2，添加配置

添加配置前先要到邮箱设置里开启SMTP服务

application.yml

spring:
  mail:
    host: smtp.qq.com
    username: xxxxxxx@qq.com #发送邮件人的邮箱
    password: xxxxx #这个密码是邮箱设置里SMTP服务生成的授权码
    default-encoding: UTF-8

3，编写发送邮箱的类

　接收类MailDO.java

package com.bootdo.oa.domain;

import java.util.Map;

/**
 * 邮件接收参数
 */

public class MailDO {

    //标题
    private String title;
    //内容
    private String content;
    //接收人邮件地址
    private String email;
    //附加，value 文件的绝对地址/动态模板数据
    private Map<String, Object> attachment;

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public String getContent() {
        return content;
    }

    public void setContent(String content) {
        this.content = content;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public Map<String, Object> getAttachment() {
        return attachment;
    }

    public void setAttachment(Map<String, Object> attachment) {
        this.attachment = attachment;
    }
}

MailService.java

package com.bootdo.oa.service;

import com.bootdo.oa.domain.MailDO;

public interface MailService {

    void sendTextMail(MailDO mailDO);

    void sendHtmlMail(MailDO mailDO,boolean isShowHtml);

    void sendTemplateMail(MailDO mailDO);
}

MailServiceImpl.java

package com.bootdo.oa.service.impl;

import com.bootdo.common.exception.SystemException;
import com.bootdo.oa.domain.MailDO;
import com.bootdo.oa.service.MailService;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.core.io.FileSystemResource;
import org.springframework.mail.MailException;
import org.springframework.mail.SimpleMailMessage;
import org.springframework.mail.javamail.JavaMailSender;
import org.springframework.mail.javamail.MimeMessageHelper;
import org.springframework.scheduling.annotation.Async;
import org.springframework.stereotype.Service;
import org.thymeleaf.TemplateEngine;
import org.thymeleaf.context.Context;

import javax.mail.MessagingException;
import javax.mail.internet.MimeMessage;
import java.io.File;

/**
 * 发送邮件
 */
@Service
public class MailServiceImpl implements MailService {

    private final static Logger log = LoggerFactory.getLogger(MailServiceImpl.class);

    //template模板引擎
    @Autowired
    private TemplateEngine templateEngine;

    @Autowired
    private JavaMailSender javaMailSender;

    @Value("${spring.mail.username}")
    private String from;

    /**
     * 纯文本邮件
     * @param mail
     */
    @Async //不解释不懂自行百度，友情提示：有坑
    @Override
    public void sendTextMail(MailDO mail){
        //建立邮件消息
        SimpleMailMessage message = new SimpleMailMessage();
        message.setFrom(from); // 发送人的邮箱
        message.setSubject(mail.getTitle()); //标题
        message.setTo(mail.getEmail()); //发给谁  对方邮箱
        message.setText(mail.getContent()); //内容
        try {
            javaMailSender.send(message); //发送
        } catch (MailException e) {
            log.error("纯文本邮件发送失败->message:{}",e.getMessage());
            throw new SystemException("邮件发送失败");
        }
    }

    /**
     * 发送的邮件是富文本（附件，图片，html等）
     * @param mailDO
     * @param isShowHtml 是否解析html
     */
    @Async
    @Override
    public void sendHtmlMail(MailDO mailDO, boolean isShowHtml) {
        try {
            MimeMessage mimeMessage = javaMailSender.createMimeMessage();
            //是否发送的邮件是富文本（附件，图片，html等）
            MimeMessageHelper messageHelper = new MimeMessageHelper(mimeMessage,true);
            messageHelper.setFrom(from);// 发送人的邮箱
            messageHelper.setTo(mailDO.getEmail());//发给谁  对方邮箱
            messageHelper.setSubject(mailDO.getTitle());//标题
            messageHelper.setText(mailDO.getContent(),isShowHtml);//false，显示原始html代码，无效果
            //判断是否有附加图片等
            if(mailDO.getAttachment() != null && mailDO.getAttachment().size() > 0){
                mailDO.getAttachment().entrySet().stream().forEach(entrySet -> {
                    try {
                        File file = new File(String.valueOf(entrySet.getValue()));
                        if(file.exists()){
                            messageHelper.addAttachment(entrySet.getKey(), new FileSystemResource(file));
                        }
                    } catch (MessagingException e) {
                        log.error("附件发送失败->message:{}",e.getMessage());
                        throw new SystemException("附件发送失败");
                    }
                });
            }
            //发送
            javaMailSender.send(mimeMessage);
        } catch (MessagingException e) {
            log.error("富文本邮件发送失败->message:{}",e.getMessage());
            throw new SystemException("邮件发送失败");
        }
    }

    /**
     * 发送模板邮件 使用thymeleaf模板
     * 若果使用freemarker模板
     *     Configuration configuration = new Configuration(Configuration.VERSION_2_3_28);
     *     configuration.setClassForTemplateLoading(this.getClass(), "/templates");
     *     String emailContent = FreeMarkerTemplateUtils.processTemplateIntoString(configuration.getTemplate("mail.ftl"), params);
     * @param mailDO
     */
    @Async
    @Override
    public void sendTemplateMail(MailDO mailDO) {
        try {
            MimeMessage mimeMessage = javaMailSender.createMimeMessage();
            MimeMessageHelper messageHelper = new MimeMessageHelper(mimeMessage,true);
            messageHelper.setFrom(from);// 发送人的邮箱
            messageHelper.setTo(mailDO.getEmail());//发给谁  对方邮箱
            messageHelper.setSubject(mailDO.getTitle()); //标题
            //使用模板thymeleaf
            //Context是导这个包import org.thymeleaf.context.Context;
            Context context = new Context();
            //定义模板数据
            context.setVariables(mailDO.getAttachment());
            //获取thymeleaf的html模板
            String emailContent = templateEngine.process("/mail/mail",context); //指定模板路径
            messageHelper.setText(emailContent,true);
            //发送邮件
            javaMailSender.send(mimeMessage);
        } catch (MessagingException e) {
            log.error("模板邮件发送失败->message:{}",e.getMessage());
            throw new SystemException("邮件发送失败");
        }
    }
}

差点忘了还有个模板 mail.html

放在templates/mail目录下

<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8">
    <title>title</title>
</head>
<body>
    <h3>你看我<span style="font-size: 35px" th:text="${username}"></span>, 哈哈哈!</h3>
</body>
</html>

4，测试

单元测试启动太慢了，直接写controller测试

　　 @GetMapping("/testMail")
    public R mail(MailDO mailDO){
        try {
            mailService.sendTextMail(mailDO);
        } catch (Exception e) {
            return R.error(e.getMessage());
        }
        return R.ok();
    }

    @GetMapping("/htmlMail")
    public R mail(MailDO mailDO){
        try {
            Map<String,Object> map = new HashMap<>();
            map.put("附件名","附件的绝对路径");
            mailDO.setAttachment(map);
            mailService.sendHtmlMail(mailDO,false);
        } catch (Exception e) {
            return R.error(e.getMessage());
        }
        return R.ok();
    }

　　 @GetMapping("/templateMail")
    public R mail(MailDO mailDO){
        try {
            Map<String,Object> map = new HashMap<>();
            map.put("username","我变大了");
            mailDO.setAttachment(map);
            mailService.sendTemplateMail(mailDO);
        } catch (Exception e) {
            return R.error(e.getMessage());
        }
        return R.ok();
    }

5，测试结果

收工。