Spring Boot 自带的 JavaMail 集成

1、获取邮箱授权码

以QQ邮箱为例，登录QQ邮箱网页版后，点击进入"设置"-"安全设置"选项。

2、集成JavaMail 

官方文档：https://docs.spring.io/spring-framework/reference/integration/email.html

2.1、引入依赖

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

2.2、添加配置

spring:
  # 邮件配置
  mail:
    # 邮件服务器地址
    host:
    # 邮件发送者
    username:
    # 授权码
    password:
    properties:
      mail:
        smtp:
          # 是否启用 SMTP 验证
          auth: true
          starttls:
            # 是否启用TLS加密
            enable: true

2.3、创建邮箱对象

@Data
public class Email implements Serializable {

    private static final long serialVersionUID = 1L;

    /**
     * 必填
     * 邮件接收方
     */
    private String[] to;

    /**
     * 必填
     * 邮件主题
     */
    private String subject;

    /**
     * 可选
     * 邮件内容
     */
    private String text;

    /**
     * 可选
     * 附件路径
     */
    private List<String> filePathList;

    /**
     * 可选
     * 图片路径
     */
    private List<String> imagePathList;

}

2.4、邮箱格式校验

public class EmailUtils {

    // 定义用于匹配大多数有效电子邮件地址的正则表达式
    private static final String EMAIL_REGEX =
            "^[a-zA-Z0-9_+&*-]+(?:\\.[a-zA-Z0-9_+&*-]+)*@(?:[a-zA-Z0-9-]+\\.)+[a-zA-Z]{2,7}$";

    // 编译正则表达式
    private static final Pattern emailPattern = Pattern.compile(EMAIL_REGEX);

    /**
     * 校验给定的email是否合法
     * @param email 待校验的电子邮件地址
     * @return 如果电子邮件地址合法返回true，否则返回false
     */
    public static boolean isValidEmail(String email) {
        if (email == null) {
            return false;
        }
        Matcher matcher = emailPattern.matcher(email);
        return matcher.matches();
    }

}

2.5、发送内容为文本的邮件

@Component
public class SendMail {

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

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

    @Autowired
    private JavaMailSender javaMailSender;


    /**
     * 发送内容为文本的邮件
     **/
    public boolean sendSimpleMail(Email email) {
        try {
            checkEmail(email);
            //创建简单邮件消息
            SimpleMailMessage message = new SimpleMailMessage();
            //发送人
            message.setFrom(from);
            //接收人
            message.setTo(email.getTo());
            //邮件主题
            message.setSubject(email.getSubject());
            //邮件内容
            message.setText(email.getText());
            //发送邮件
            javaMailSender.send(message);
        } catch (Exception e) {
            log.error("邮件发送失败：{}", email, e);
            return false;
        }
        log.error("邮件发送成功：{}", Arrays.toString(email.getTo()));
        return true;
    }

}

2.6、发送内容为html的邮件

@Component
public class SendMail {

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

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

    @Autowired
    private JavaMailSender javaMailSender;


    /**
     * 发送内容为html的邮件
     **/
    public boolean sendMimeMail(Email email) {
        try {
            checkEmail(email);
            //创建MINE邮件消息
            MimeMessage message = javaMailSender.createMimeMessage();
            MimeMessageHelper mineHelper = new MimeMessageHelper(message, true);
            //发送人
            mineHelper.setFrom(from);
            //接收人
            mineHelper.setTo(email.getTo());
            //邮件主题
            mineHelper.setSubject(email.getSubject());
            //邮件内容，true 表示带有附件或html
            mineHelper.setText(email.getText(),true);
            //发送邮件
            javaMailSender.send(message);
        } catch (Exception e) {
            log.error("邮件发送失败：{}", email, e);
            return false;
        }
        log.error("邮件发送成功：{}", Arrays.toString(email.getTo()));
        return true;
    }

}

2.7、发送内容为图片的邮件

内联资源通过使用指定的Content-ID添加到MimeMessage。添加文本和资源的顺序非常重要。一定要先添加文本，然后再添加资源。如果你用另一种方式来做，它是行不通的。

@Component
public class SendMail {

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

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

    @Autowired
    private JavaMailSender javaMailSender;


    /**
     * 发送内容为图片的邮件
     **/
    public boolean sendImageMail(Email email) {
        try {
            checkEmail(email);
            //创建MINE邮件消息
            MimeMessage message = javaMailSender.createMimeMessage();
            MimeMessageHelper mineHelper = new MimeMessageHelper(message, true);
            //发送人
            mineHelper.setFrom(from);
            //接收人
            mineHelper.setTo(email.getTo());
            //邮件主题
            mineHelper.setSubject(email.getSubject());
            if (CollectionUtils.isNotEmpty(email.getImagePathList())) {
                StringBuilder htmlContent = new StringBuilder();
                htmlContent.append("<html><body>");
                for(int i = 0; i < email.getImagePathList().size(); i++){
                    String imagePath = email.getImagePathList().get(i);
                    File file = new File(imagePath);
                    if (!file.exists()) {
                        log.error("图片不存在：{}", imagePath);
                        continue;
                    }
                    String contentId = "identifier" + i;
                    htmlContent.append("<img src='cid:").append(contentId).append("' style='max-width:600px;display:block;margin-bottom:10px;'/>");
                }
                htmlContent.append("</body></html>");
                //邮件内容，true 表示带有附件或html
                mineHelper.setText(htmlContent.toString(),true);
                for(int i = 0; i < email.getImagePathList().size(); i++){
                    String imagePath = email.getImagePathList().get(i);
                    File file = new File(imagePath);
                    if (!file.exists()) {
                        log.error("图片不存在：{}", imagePath);
                        continue;
                    }
                    //添加内联资源，一个id对应一个资源，最终通过id来找到该资源
                    String contentId = "identifier" + i;
                    FileSystemResource resource = new FileSystemResource(file);
                    mineHelper.addInline(contentId, resource);
                }
            }
            //发送邮件
            javaMailSender.send(message);
        } catch (Exception e) {
            log.error("邮件发送失败：{}", email, e);
            return false;
        }
        log.error("邮件发送成功：{}", Arrays.toString(email.getTo()));
        return true;
    }

}

2.7、发送内容为文本且包含图片的邮件

@Component
public class SendMail {

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

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

    @Autowired
    private JavaMailSender javaMailSender;


     /**
     * 发送内容为文本且包含图片的邮件
     **/
    public boolean sendTextImageMail(Email email) {
        try {
            checkEmail(email);
            //创建MINE邮件消息
            MimeMessage message = javaMailSender.createMimeMessage();
            MimeMessageHelper mineHelper = new MimeMessageHelper(message, true);
            //发送人
            mineHelper.setFrom(from);
            //接收人
            mineHelper.setTo(email.getTo());
            //邮件主题
            mineHelper.setSubject(email.getSubject());
            if (CollectionUtils.isNotEmpty(email.getImagePathList())) {
                StringBuilder htmlContent = new StringBuilder();
                htmlContent.append("<html><body>");
                htmlContent.append("<div>").append(email.getText()).append("</div>");
                for(int i = 0; i < email.getImagePathList().size(); i++){
                    String imagePath = email.getImagePathList().get(i);
                    File file = new File(imagePath);
                    if (!file.exists()) {
                        log.error("图片不存在：{}", imagePath);
                        continue;
                    }
                    String contentId = "identifier" + i;
                    htmlContent.append("<img src='cid:").append(contentId).append("' style='max-width:600px;display:block;margin-bottom:10px;'/>");
                }
                htmlContent.append("</body></html>");
                //邮件内容，true 表示带有附件或html
                mineHelper.setText(htmlContent.toString(),true);
                for(int i = 0; i < email.getImagePathList().size(); i++){
                    String imagePath = email.getImagePathList().get(i);
                    File file = new File(imagePath);
                    if (!file.exists()) {
                        log.error("图片不存在：{}", imagePath);
                        continue;
                    }
                    //添加内联资源，一个id对应一个资源，最终通过id来找到该资源
                    String contentId = "identifier" + i;
                    FileSystemResource resource = new FileSystemResource(file);
                    mineHelper.addInline(contentId, resource);
                }
            }else{
                mineHelper.setText(email.getText());
            }
            //发送邮件
            javaMailSender.send(message);
        } catch (Exception e) {
            log.error("邮件发送失败：{}", email, e);
            return false;
        }
        log.error("邮件发送成功：{}", Arrays.toString(email.getTo()));
        return true;
    }

}

2.8、发送带附件的邮件

@Component
public class SendMail {

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

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

    @Autowired
    private JavaMailSender javaMailSender;


    /**
     * 发送带附件的邮件
     * 邮件内容可以为文本或html
     **/
    public boolean sendAttachmentMail(Email email) {
        try {
            checkEmail(email);
            //创建MINE邮件消息
            MimeMessage message = javaMailSender.createMimeMessage();
            MimeMessageHelper mineHelper = new MimeMessageHelper(message, true);
            //发送人
            mineHelper.setFrom(from);
            //接收人
            mineHelper.setTo(email.getTo());
            //邮件主题
            mineHelper.setSubject(email.getSubject());
            //邮件内容，true 表示带有附件或html
            mineHelper.setText(email.getText(),true);
            // 添加附件
            if (CollectionUtils.isNotEmpty(email.getFilePathList())) {
                for (String filePath : email.getFilePathList()) {
                    File file = new File(filePath);
                    if (!file.exists()) {
                        log.error("附件不存在：{}", filePath);
                        continue;
                    }
                    FileSystemResource resource = new FileSystemResource(file);
                    mineHelper.addAttachment(Objects.requireNonNull(resource.getFilename()), resource);
                }
            }
            //发送邮件
            javaMailSender.send(message);
        } catch (Exception e) {
            log.error("邮件发送失败：{}", email, e);
            return false;
        }
        log.error("邮件发送成功：{}", Arrays.toString(email.getTo()));
        return true;
    }

}

2.9、checkEmail方法

    /**
     * 校验邮件
     **/
    private static boolean checkEmail(Email email) {
        log.error("开始发送邮件：{}", email);
        if (email == null) {
            log.error("邮件参数错误：{}", (Object) null);
            return false;
        }
        if (email.getTo() == null || email.getTo().length == 0) {
            log.error("邮件接收人不能为空：{}", email);
            return false;
        }
        if (StringUtils.isEmpty(email.getSubject())) {
            log.error("邮件主题不能为空：{}", email);
            return false;
        }
        for (String to : email.getTo()) {
            if (!EmailUtils.isValidEmail(to)) {
                log.error("邮件接收人格式错误：{}", to);
                return false;
            }
        }
        return true;
    }

3、在业务中怎么使用

在其他服务中直接注入SendMail即可

@Autowired
private SendMail sendMail;

3.1、发送内容为文本的邮件

Email email = new Email();
email.setTo(new String[]{"ceshi@qq.com"});
email.setSubject("测试邮件");
email.setText("测试邮件");
boolean b = sendMail.sendSimpleMail(email);
System.out.println(b);

3.2、发送内容为html的邮件

Email email = new Email();
email.setTo(new String[]{"ceshi@qq.com"});
email.setSubject("测试邮件");
email.setText("<html><body><h1>测试邮件</h1></body></html>");
boolean b = sendMail.sendMimeMail(email);
System.out.println(b);

3.3、发送内容为图片的邮件

Email email = new Email();
email.setTo(new String[]{"ceshi@qq.com"});
email.setSubject("测试邮件");
email.setImagePathList(Arrays.asList("c:\\ceshi.jpg");
boolean b = sendMail.sendImageMail(email);
System.out.println(b);

3.4、发送内容为文本且包含图片的邮件

Email email = new Email();
email.setTo(new String[]{"ceshi@qq.com"});
email.setSubject("测试邮件");
email.setText("测试邮件");
email.setImagePathList(Arrays.asList("c:\\ceshi.jpg");
boolean b = sendMail.sendTextImageMail(email);
System.out.println(b);

3.5、发送带附件的邮件

Email email = new Email();
email.setTo(new String[]{"ceshi@qq.com"});
email.setSubject("测试邮件");
email.setText("测试邮件");
email.setFilePathList(Arrays.asList("c:\\ceshi.jpg");
boolean b = sendMail.sendAttachmentMail(email);
System.out.println(b);