📃 邮件服务

一、配置依赖

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-mail</artifactId>
</dependency>
<dependency>
    <groupId>com.sun.mail</groupId>
    <artifactId>javax.mail</artifactId>
    <version>RELEASE</version>
</dependency>

在 application.yaml 中配置：

spring:
  mail:
    host: smtp.163.com
    username: quanzaiyu@163.com
    password: xxxxxx
    default-encoding: UTF-8

二、创建Mail服务

定义接口

package com.example.mail.service;

public interface MailService {
  public void sendSimpleMail(String to, String subject, String content);
  public void sendHtmlMail(String to, String subject, String content);
  public void sendAttachmentsMail(String to, String subject, String content, String filePath);
  public void sendInlineResourceMail(String to, String subject, String content, String rscPath, String rscId);
}

实现接口

package com.example.mail.service.impl;

import com.example.mail.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.SimpleMailMessage;
import org.springframework.mail.javamail.JavaMailSender;
import org.springframework.mail.javamail.MimeMessageHelper;
import org.springframework.stereotype.Component;

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

@Component
public class MailServiceImpl implements MailService {
    private final Logger logger = LoggerFactory.getLogger(this.getClass());

    @Autowired
    private JavaMailSender mailSender;

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

    /**
     * 发送文本邮件
     * @param to
     * @param subject
     * @param content
     */
    @Override
    public void sendSimpleMail(String to, String subject, String content) {
        SimpleMailMessage message = new SimpleMailMessage();
        message.setFrom(from);
        message.setTo(to);
        message.setSubject(subject);
        message.setText(content);
        try {
            mailSender.send(message);
            logger.info("简单邮件已经发送。");
        } catch (Exception e) {
            logger.error("发送简单邮件时发生异常！", e);
        }
    }

    /**
     * 发送html邮件
     * @param to
     * @param subject
     * @param content
     */
    @Override
    public void sendHtmlMail(String to, String subject, String content) {
        MimeMessage message = mailSender.createMimeMessage();
        try {
            //true表示需要创建一个multipart message
            MimeMessageHelper helper = new MimeMessageHelper(message, true);
            helper.setFrom(from);
            helper.setTo(to);
            helper.setSubject(subject);
            helper.setText(content, true);

            mailSender.send(message);
            logger.info("html邮件发送成功");
        } catch (MessagingException e) {
            logger.error("发送html邮件时发生异常！", e);
        }
    }

    /**
     * 发送带附件的邮件
     * @param to
     * @param subject
     * @param content
     * @param filePath
     */
    @Override
    public void sendAttachmentsMail(String to, String subject, String content, String filePath) {
        MimeMessage message = mailSender.createMimeMessage();
        try {
            MimeMessageHelper 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 = filePath.substring(filePath.lastIndexOf(File.separator));
            helper.addAttachment(fileName, file);
            mailSender.send(message);
            logger.info("带附件的邮件已经发送。");
        } catch (MessagingException e) {
            logger.error("发送带附件的邮件时发生异常！", e);
        }
    }


    /**
     * 发送正文中有静态资源（图片）的邮件
     * @param to
     * @param subject
     * @param content
     * @param rscPath
     * @param rscId
     */
    @Override
    public void sendInlineResourceMail(String to, String subject, String content, String rscPath, String rscId) {
        MimeMessage message = mailSender.createMimeMessage();
        try {
            MimeMessageHelper helper = new MimeMessageHelper(message, true);
            helper.setFrom(from);
            helper.setTo(to);
            helper.setSubject(subject);
            helper.setText(content, true);

            FileSystemResource res = new FileSystemResource(new File(rscPath));
            helper.addInline(rscId, res);

            mailSender.send(message);
            logger.info("嵌入静态资源的邮件已经发送。");
        } catch (MessagingException e) {
            logger.error("发送嵌入静态资源的邮件时发生异常！", e);
        }
    }
}

三、发送文本邮件

编写单元测试：

package com.example.mail.service;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;

@RunWith(SpringRunner.class)
@SpringBootTest
public class MailServiceTest {
    @Autowired
    private MailService mailService;

    @Test
    public void testSimpleMail() throws Exception {
        mailService.sendSimpleMail("731734107@qq.com","test simple mail"," hello this is simple mail");
    }
}

通过 mailService.sendSimpleMail 发送普通文本邮件

四、发送HTML邮件

编写单元测试：

package com.example.demo.service;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;

@RunWith(SpringRunner.class)
@SpringBootTest
public class MailServiceTest {
    @Autowired
    private MailService mailService;

    @Test
    public void testHtmlMail() throws Exception {
        String content="<html>\n" +
                "<body>\n" +
                "    <h3>hello world ! 这是一封html邮件!</h3>\n" +
                "</body>\n" +
                "</html>";
        mailService.sendHtmlMail("731734107@qq.com","test simple mail",content);
    }
}

通过 mailService.sendHtmlMail 发送HTML格式的邮件

五、发送附件

编写单元测试：

package com.example.demo.service;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;

@RunWith(SpringRunner.class)
@SpringBootTest
public class MailServiceTest {
    @Autowired
    private MailService mailService;

    @Test
    public void sendAttachmentsMail() {
        String filePath= "C:\\Users\\quanzaiyu\\OneDrive\\我的\\logo.png";
        mailService.sendAttachmentsMail("731734107@qq.com", "主题：带附件的邮件", "有附件，请查收！", filePath);
    }
}

通过 mailService.sendAttachmentsMail 发送带附件的邮件

六、发送图文邮件

编写单元测试：

package com.example.demo.service;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;

@RunWith(SpringRunner.class)
@SpringBootTest
public class MailServiceTest {
    @Autowired
    private MailService mailService;

    @Test
    public void sendInlineResourceMail() {
        String rscId = "yu";
        String content="<html><body>这是有图片的邮件：<img src=\'cid:" + rscId + "\' ></body></html>";
        String imgPath = "C:\\Users\\quanzaiyu\\OneDrive\\我的\\logo.png";
        mailService.sendInlineResourceMail("731734107@qq.com", "主题：这是有图片的邮件", content, imgPath, rscId);
    }
}

通过 mailService.sendInlineResourceMail 发送图文邮件

七、发送模板消息

使用此种方式发送邮件, 需要将模板引擎 thymeleaf 加入依赖：

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

编写单元测试：

package com.example.demo.service;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;

import org.thymeleaf.TemplateEngine;
import org.thymeleaf.context.Context;

@RunWith(SpringRunner.class)
@SpringBootTest
public class MailServiceTest {
    @Autowired
    private MailService mailService;

    @Autowired
    private TemplateEngine templateEngine;

    @Test
    public void sendTemplateMail() {
        // 创建邮件正文
        Context context = new Context();
        // 设置变量
        context.setVariable("name", "categories");
        String emailContent = templateEngine.process("emailTemplate", context);
        mailService.sendHtmlMail("731734107@qq.com","主题：这是模板邮件", emailContent);
    }
}

同样地, 模板也是 HTML, 因此使用 mailService.sendHtmlMail 发送邮件即可

配置模板文件：
resources/templates/emailTemplate.html

<!DOCTYPE html>
<html lang="zh" xmlns:th="http://www.thymeleaf.org">
    <head>
        <meta charset="UTF-8"/>
        <title>Title</title>
    </head>
    <body>
        您好,这是验证邮件,请点击下面的链接完成验证,<br/>
        <a href="#" th:href="@{ https://www.xiaoyulive.top/{name}(name=${name}) }">激活账号</a>
    </body>
</html>

其中 name 参数来源于 context.setVariable()