Email概述

邮箱功能在通用系统都会存在，比如当用户忘记密码的时候，就会通过邮箱的方式找回密码、重置密码等，相对于短信的方式用于登录、验证，邮箱一般会用于校验身份、核实等应用场景。

本文通过一个小案例来整合邮箱，在SpringBoot实现邮箱功能。

添加依赖

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

<!-- Spring Boot 模板依赖 -->
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-thymeleaf</artifactId>
</dependency>

配置文件

这里我们使用QQ邮箱来集成。参考下面的配置即可，其中password需要使用QQ邮箱生成授权码

QQ邮箱帮助文档 (opens new window)

spring:
  mail:
    host: smtp.qq.com
    port: 465
    username: 846212939@qq.com
    password: 
    protocol: smtp
    test-connection: true
    default-encoding: UTF-8
    properties:
      mail.smtp.auth: true
      mail.smtp.starttls.enable: true
      mail.smtp.starttls.required: true
      mail.smtp.ssl.enable: true
      mail.display.sendmail: spring-boot-demo

服务层

邮箱接口

public interface MailService {
    /**
     * 发送文本邮件
     *
     * @param to      收件人地址
     * @param subject 邮件主题
     * @param content 邮件内容
     * @param cc      抄送地址
     */
    void sendSimpleMail(String to, String subject, String content, String... cc);

    /**
     * 发送HTML邮件
     *
     * @param to      收件人地址
     * @param subject 邮件主题
     * @param content 邮件内容
     * @param cc      抄送地址
     * @throws MessagingException 邮件发送异常
     */
    void sendHtmlMail(String to, String subject, String content, String... cc) throws MessagingException;

    /**
     * 发送带附件的邮件
     *
     * @param to       收件人地址
     * @param subject  邮件主题
     * @param content  邮件内容
     * @param filePath 附件地址
     * @param cc       抄送地址
     * @throws MessagingException 邮件发送异常
     */
    void sendAttachmentsMail(String to, String subject, String content, String filePath, String... cc) throws MessagingException;

    /**
     * 发送正文中有静态资源的邮件
     *
     * @param to      收件人地址
     * @param subject 邮件主题
     * @param content 邮件内容
     * @param rscPath 静态资源地址
     * @param rscId   静态资源id
     * @param cc      抄送地址
     * @throws MessagingException 邮件发送异常
     */
    void sendResourceMail(String to, String subject, String content, String rscPath, String rscId, String... cc) throws MessagingException;
}

具体实现

@Service
public class MailServiceImpl implements MailService {
    @Autowired
    private JavaMailSender mailSender;
    @Value("${spring.mail.username}")
    private String from;

    /**
     * 发送文本邮件
     *
     * @param to      收件人地址
     * @param subject 邮件主题
     * @param content 邮件内容
     * @param cc      抄送地址
     */
    @Override
    public void sendSimpleMail(String to, String subject, String content, String... cc) {
        SimpleMailMessage message = new SimpleMailMessage();
        message.setFrom(from);
        message.setTo(to);
        message.setSubject(subject);
        message.setText(content);
        if (ArrayUtil.isNotEmpty(cc)) {
            message.setCc(cc);
        }
        mailSender.send(message);
    }

    /**
     * 发送HTML邮件
     *
     * @param to      收件人地址
     * @param subject 邮件主题
     * @param content 邮件内容
     * @param cc      抄送地址
     * @throws MessagingException 邮件发送异常
     */
    @Override
    public void sendHtmlMail(String to, String subject, String content, String... cc) throws MessagingException {
        MimeMessage message = mailSender.createMimeMessage();
        MimeMessageHelper helper = new MimeMessageHelper(message, true);
        helper.setFrom(from);
        helper.setTo(to);
        helper.setSubject(subject);
        helper.setText(content, true);
        if (ArrayUtil.isNotEmpty(cc)) {
            helper.setCc(cc);
        }
        mailSender.send(message);
    }

    /**
     * 发送带附件的邮件
     *
     * @param to       收件人地址
     * @param subject  邮件主题
     * @param content  邮件内容
     * @param filePath 附件地址
     * @param cc       抄送地址
     * @throws MessagingException 邮件发送异常
     */
    @Override
    public void sendAttachmentsMail(String to, String subject, String content, String filePath, String... cc) throws MessagingException {
        MimeMessage message = mailSender.createMimeMessage();

        MimeMessageHelper helper = new MimeMessageHelper(message, true);
        helper.setFrom(from);
        helper.setTo(to);
        helper.setSubject(subject);
        helper.setText(content, true);
        if (ArrayUtil.isNotEmpty(cc)) {
            helper.setCc(cc);
        }
        FileSystemResource file = new FileSystemResource(new File(filePath));
        // 这里是windows
        String fileName = filePath.substring(filePath.lastIndexOf('/'));
        // Linux下
        //String fileName = filePath.substring(filePath.lastIndexOf(File.separator));
        helper.addAttachment(fileName, file);

        mailSender.send(message);
    }

    /**
     * 发送正文中有静态资源的邮件
     *
     * @param to      收件人地址
     * @param subject 邮件主题
     * @param content 邮件内容
     * @param rscPath 静态资源地址
     * @param rscId   静态资源id
     * @param cc      抄送地址
     * @throws MessagingException 邮件发送异常
     */
    @Override
    public void sendResourceMail(String to, String subject, String content, String rscPath, String rscId, String... cc) throws MessagingException {
        MimeMessage message = mailSender.createMimeMessage();

        MimeMessageHelper helper = new MimeMessageHelper(message, true);
        helper.setFrom(from);
        helper.setTo(to);
        helper.setSubject(subject);
        helper.setText(content, true);
        if (ArrayUtil.isNotEmpty(cc)) {
            helper.setCc(cc);
        }
        FileSystemResource res = new FileSystemResource(new File(rscPath));
        helper.addInline(rscId, res);

        mailSender.send(message);
    }
}

具体实现

public class MailServiceTest extends SpringBootEmailApplicationTests {

    @Autowired
    private MailService mailService;
    @Autowired
    private TemplateEngine templateEngine;
    @Autowired
    private ApplicationContext context;

    /**
     * 测试简单邮件
     */
    @Test
    public void sendSimpleMail() {
        mailService.sendSimpleMail("846212939@qq.com", "这是一封简单邮件", "这是一封普通的SpringBoot测试邮件");
    }

    /**
     * 测试HTML邮件
     *
     * @throws MessagingException 邮件异常
     */
    @Test
    public void sendHtmlMail() throws MessagingException {
        Context context = new Context();
        context.setVariable("project", "Spring Boot Demo");
        context.setVariable("author", "wxx");
        context.setVariable("url", "https://github.com/xkcoding/spring-boot-demo");

        String emailTemplate = templateEngine.process("welcome", context);
        mailService.sendHtmlMail("846212939@qq.com", "这是一封模板HTML邮件", emailTemplate);
    }

    /**
     * 测试HTML邮件，自定义模板目录
     *
     * @throws MessagingException 邮件异常
     */
    @Test
    public void sendHtmlMail2() throws MessagingException {

        SpringResourceTemplateResolver templateResolver = new SpringResourceTemplateResolver();
        templateResolver.setApplicationContext(context);
        templateResolver.setCacheable(false);
        templateResolver.setPrefix("classpath:/email/");
        templateResolver.setSuffix(".html");

        templateEngine.setTemplateResolver(templateResolver);

        Context context = new Context();
        context.setVariable("project", "Spring Boot Demo");
        context.setVariable("author", "Yangkai.Shen");
        context.setVariable("url", "https://github.com/xkcoding/spring-boot-demo");

        String emailTemplate = templateEngine.process("test", context);
        mailService.sendHtmlMail("846212939@qq.com", "这是一封模板HTML邮件", emailTemplate);
    }

    /**
     * 测试附件邮件
     *
     * @throws MessagingException 邮件异常
     */
    @Test
    public void sendAttachmentsMail() throws MessagingException {
        URL resource = ResourceUtil.getResource("static/123.jpg");
        mailService.sendAttachmentsMail("846212939@qq.com", "这是一封带附件的邮件", "邮件中有附件，请注意查收！", resource.getPath());
    }

    /**
     * 测试静态资源邮件
     *
     * @throws MessagingException 邮件异常
     */
    @Test
    public void sendResourceMail() throws MessagingException {
        String rscId = "wxx";
        String content = "<html><body>这是带静态资源的邮件<br/><img src=\'cid:" + rscId + "\' ></body></html>";
        URL resource = ResourceUtil.getResource("static/123.jpg");
        mailService.sendResourceMail("846212939@qq.com", "这是一封带静态资源的邮件", content, resource.getPath(), rscId);
    }
}

相关的静态文件和模板可以参考https://github.com/xkcoding/spring-boot-demo/tree/master/demo-email代码

参考

https://github.com/xkcoding/spring-boot-demo/tree/master/demo-email