springboot发送邮件内容及换行

• 首先搭建好springboot项目，引入pom文件
  说明：若下面的包并非在新建demo引入的那么后续引入的时候注意选择版本，尽量不要选最新版，优先高引入量的版本，否则不兼容会提示包错误

<!--邮件发送-->
<!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-mail -->
<dependency>
	<groupId>org.springframework.boot</groupId>
	<artifactId>spring-boot-starter-mail</artifactId>
	<version>2.2.6.RELEASE</version>
</dependency>

• 配置yml文件
  说明：这里以qq为例，其他139邮箱、163邮箱设置对应的协议授权服务器端口等信息

spring:
  mail:
    username: xxxxxx@qq.com #授权邮箱用户
    password: debnxxxxxxxxxxbf #授权码，需开启POP3/SMTP服务允许POP3/SMTP服务
    host: smtp.qq.com #授权服务器
    properties:
      mail:
        smtp:
          ssl:
            enable: true #开启SSL

• 新建自定义MailService接口类

public interface MailService {
    /**
     * 发送简单邮件
     * @param subject 邮件主题
     * @param text 邮件内容
     * @param receiver 收件人账户
     */
    void sendSimpleMail(String subject,String text,String receiver);

    /**
     * 发送带附件的邮件
     * @param subject 邮件主题
     * @param text 邮件内容
     * @param receiver 收件人账户
     * @param attachments 附件
     */
    void sendAttachmentMail(String subject, String text, String receiver, Map<String, String> attachments);
}

• 新建MailServiceImpl类去实现MailService

@Service
public class MailServiceImpl implements MailService{
    @Autowired
    private JavaMailSenderImpl mailSender;

    @Override
    public void sendSimpleMail(String subject, String text, String receiver) {

        SimpleMailMessage message = new SimpleMailMessage();
        message.setSubject(subject);
        message.setText(text);
        message.setTo(receiver);//收件人邮箱
        message.setFrom(Constants.MailQQsetFrom);//Constants.MailQQsetFrom值为发件人账户，需与yml配置文件保持一致
        mailSender.send(message);
    }

    @Override
    public void sendAttachmentMail(String subject, String text, String receiver, Map<String, String> attachments) {

        MimeMessage mimeMessage = mailSender.createMimeMessage();

        try{

            //multipart 是否上传附件
            MimeMessageHelper mimeMessageHelper = new MimeMessageHelper(mimeMessage,true);

            mimeMessageHelper.setSubject(subject);
            mimeMessageHelper.setText(text);
            mimeMessageHelper.setTo(receiver);//收件人邮箱
            mimeMessageHelper.setFrom(Constants.MailQQsetFrom);//Constants.MailQQsetFrom值为发件人账户，需与yml配置文件保持一致

            //上传附件
            attachments.forEach((k,v) -> {
                try{
                    mimeMessageHelper.addAttachment(k,new File(v));
                }catch (MessagingException e){
                    e.printStackTrace();
                }
            });
        }catch (Exception e){
            e.printStackTrace();
        }

        mailSender.send(mimeMessage);
    }
}

• 直接调用即可

@RestController
public class test {
    @Autowired
    MailService mailService;

    @RequestMapping("testmail")
    public void testmail() {
    	//java邮件内容需要换行的话使用\n;
    	String title="邮件标题文字",content="",tomail="xxxxx@139.com";
		content="尊敬的xxx您好：\n";
		content+="次邮件内容为测试，详情如下：\n";
        mailService.sendSimpleMail(title, content, tomail);//这里以普通文本邮件为例，带附件邮件同理
    }
}