Springboot整合实现邮件发送的原理详解

@Autowired
    private JavaMailSenderImpl mailSender;
    @Override
    public void sendInlineAndAttachMail(String to, String subject, String content,  String filePath,String                       rscPath, String rscId) {
        logger.info("发送带图片邮件开始：{},{},{},{},{}", to, subject, content, rscPath, rscId);
        MimeMessage message = mailSender.createMimeMessage();
        MimeMessageHelper helper;
        try {
            helper = new MimeMessageHelper(message, true);
            helper.setFrom(from);
            helper.setTo(to);
            helper.setSubject(subject);
            helper.setText(content, true);
            FileSystemResource file = new FileSystemResource(new File(filePath));
            String fileName = file.getFilename();
            helper.addAttachment(fileName, file);
            FileSystemResource res = new FileSystemResource(new File(rscPath));
            helper.addInline(rscId, res);//重复使用添加多个图片
            mailSender.send(message);
            logger.info("发送带图片和附件邮件成功");
        } catch (MessagingException e) {
            logger.error("发送带图片和附件邮件失败", e);
        }
    }

@Configuration
@ConditionalOnProperty(prefix = "spring.mail", name = "host")
class MailSenderPropertiesConfiguration {
    private final MailProperties properties;
    MailSenderPropertiesConfiguration(MailProperties properties) {
        this.properties = properties;
    }
    @Bean
    @ConditionalOnMissingBean
    public JavaMailSenderImpl mailSender() {
        JavaMailSenderImpl sender = new JavaMailSenderImpl();
        applyProperties(sender);
        return sender;
    }

@ConfigurationProperties(prefix = "spring.mail")
public class MailProperties {
    private static final Charset DEFAULT_CHARSET = StandardCharsets.UTF_8;
    private String host;
    private Integer port;
    private String username;
    private String passWord;
    private String protocol = "smtp";
    private Charset defaultEncoding = DEFAULT_CHARSET;
    private Map<String, String> properties = new HashMap<>();
}

<!--javax.mail 邮件发送-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-mail</artifactId>
        </dependency>

#邮件配置
#SMTP服务器地址
spring.mail.host=smtp.qq.com    
#登陆账号
spring.mail.username=2590742958@qq.com
#注意这里不是邮箱密码，而是SMTP授权密码
spring.mail.password=lvlpxkujplqbdh
spring.mail.default-encoding=UTF-8
#开启加密验证
spring.mail.properties.mail.smtp.ssl.enable=true
#以下项不用改动
spring.mail.properties.mail.smtp.starttls.enable: true
spring.mail.roperties.mail.smtp.starttls.required: true

public class MailServiceImpl implements MailService {
    private final Logger logger = LoggerFactory.getLogger(MailServiceImpl.class);
    //使用@Value注入application.properties中指定的用户名
    @Value("${spring.mail.username}")
    private String from;
​
    @Autowired
    //用于发送文件
    private JavaMailSender mailSender;
     @Override
    public void sendAttachmentMail(String to, String subject, String content, String filePath) {
​
        logger.info("发送带附件邮件开始：{},{},{},{}", to, subject, content, filePath);
        MimeMessage message = mailSender.createMimeMessage();
​
        MimeMessageHelper helper;
        try {
            helper = new MimeMessageHelper(message, true);
            helper.setFrom(from);
            helper.setTo(to);
            helper.setSubject(subject);
            helper.setText(content, true);
            FileSystemResource file = new FileSystemResource(new File(filePath));
            String fileName = file.getFilename();
            helper.addAttachment(fileName, file);//添加附件，可多次调用该方法添加多个附件
            mailSender.send(message);
            logger.info("发送带附件邮件成功");
        } catch (MessagingException e) {
            logger.error("发送带附件邮件失败", e);
        }

public interface MailService {
    
    void sendSimpleMail(String to, String subject, String content);
    
    void sendhtmlMail(String to, String subject, String content);
    
    void sendAttachmentMail(String to, String subject, String content, String filePath);
    
    void sendInlineResourceMail(String to, String subject, String content, String rscPath, String rscId);
    
    void sendInlineAndAttachMail(String to, String subject, String content,String filePath, String              rscPath, String rscId);
}

@Controller
public class MailContorller {
​
    @Autowired
    private MailService mailService;
    @Autowired
    private TemplateEngine templateEngine;
    @Resource
    private UserService userService;
​
    //这一步是获取application.properties中设置的发件人邮箱地址
    @Value("${spring.mail.username}")
    private String Email;
​
    @RequestMapping("/sendTemplate")
    
    public String sendTemplate(@RequestParam("Email") String Email, Model model) {
        //具体的业务
        User usermail= userService.retrieve(Email);
        System.out.println(usermail);
        if (usermail !=null){
            //向Thymeleaf模板传值，并解析成字符串
            //通过Context构造模版中变量需要的值
            Context context = new Context();
            context.setVariable("id", "001");
            String emailContent = templateEngine.process("emailTemplate", context);
            mailService.sendHtmlMail(Email,"密码找回验证", emailContent);
            return "Login";
        }
        else if(StringUtils.isEmpty(Email)){
            model.addAttribute("yuoxiang","邮箱信息不能为空");
            return "Login";
        }
        else {
            model.addAttribute("yuoxiang","邮箱错误或者与绑定账号不一致");
            return "Login";
        }
    }

<!DOCTYPE html>
<html lang="en" xmlns:th="Http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8">
    <title>密码验证</title>
</head>
<body>
<span style="color:#5ed02b;font-weight:600;font-size: 18px">您好，欢迎您的查看，这是一封验证邮件，请根据下面系统找回的密码完成登录，感谢您的支持！</span><br>
</body>
</html>