使用SpringBoot发邮件

SpringBoot中已有发邮件的工具包，只需要引用即可使用

1，pom引用

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

2，在配置文件中配置邮件服务器信息。这里需要一个可用的邮件服务器。

spring.mail.default-encoding=utf-8
spring.mail.host=mail.xxxx.com
spring.mail.username=xxxx@xxxx.com
spring.mail.password=password

3，编写发邮件service，调用JavaMailSender.send()即可，支持简单文本邮件、富文本邮件、html邮件

 Service代码如下

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.core.io.FileSystemResource;
import org.springframework.mail.MailException;
import org.springframework.mail.SimpleMailMessage;
import org.springframework.mail.javamail.JavaMailSender;
import org.springframework.mail.javamail.MimeMessageHelper;
import org.springframework.stereotype.Service;

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

@Service
public class EmailService {
    @Autowired
    private JavaMailSender mailSender;

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

    /**
     * 发送简单文本邮件
     * @param content 邮件正文
     * @param subject 邮件主题
     * @param to 邮件接收地址
     * */
    public void sendSimpleMail(String to, String subject, String content) throws MailException {
        System.out.println("-----from:" + from);
        System.out.println("-----to:" + to);
        System.out.println("-----subject:" + subject);
        System.out.println("-----content:" + content);

        SimpleMailMessage message = new SimpleMailMessage();
        message.setFrom(from);
        message.setTo(to);
        message.setSubject(subject);
        message.setText(content);
        mailSender.send(message);
    }

    /**
     * 发送富文本邮件
     * @param content 邮件正文
     * @param rscId 设置在header头中的文件ID 
     * @param rscPath 图片路径
     * @param subject 邮件主题
     * @param to 邮件接收地址
     * */
    public void sendRichTextMail(String to, String subject, String content, String rscPath, String rscId) throws MessagingException {
        //MimeMessageHelper支持发送复杂邮件模板，支持文本、附件、HTML、图片等。
        //如果需要发送多张图片，可以改变传参方式，使用集合添加多个<img src='cid:rscId'>和helper.addInline(rscId, res);即可实现

        MimeMessage message = mailSender.createMimeMessage();
        MimeMessageHelper helper = new MimeMessageHelper(message, true);
        helper.setFrom(from);
        helper.setTo(to);
        helper.setSubject(subject);
        helper.setText(content, true);
        File file = new File(rscPath);
        FileSystemResource res = new FileSystemResource(file);
        helper.addInline(rscId, res);

        mailSender.send(message);

    }

    /**
     * 发送HTML邮件
     * @param to 邮件接收地址
     * @param subject 邮件主题
     * @param content 邮件正文
     * */
    public void sendHtmlMail(String to, String subject, String content) throws MessagingException {
        MimeMessage message = mailSender.createMimeMessage();
        //true 表⽰示需要创建⼀一个 multipart message
        MimeMessageHelper helper = new MimeMessageHelper(message, true);
        helper.setFrom(from);
        helper.setTo(to);
        helper.setSubject(subject);
        helper.setText(content, true);
        mailSender.send(message);
    }
}

 

controller测试代码

 

import com.hyp.emailtest.service.EmailService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.mail.MailException;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;

import javax.mail.MessagingException;

@RestController
@RequestMapping("Mail")
public class EmailController {

    @Autowired
    private EmailService emailService;
   
    //发送简单文本邮件
    @RequestMapping(value = "send", method = RequestMethod.GET)
    public void Send() {
        String To = "test@xxxx.com";
        String Subject = "Java发邮件测试";
        String Content = "这是一封来自JavaMailSender自动发送的测试邮件";
        try {
            emailService.sendSimpleMail(To, Subject, Content);
            System.out.println("发送成功");
        } catch (MailException ex) {
            System.out.println("发送失败");
            System.out.println(ex.toString());
        }
    }

    //发送富文本邮件
    @RequestMapping(value = "sendImg", method = RequestMethod.GET)
    public void SendWithImg() {
        String to = "test@xxxx.com";
        String subject = "Java发邮件测试";
        String rscId = "img1";
        String content = "<html><body><img width='250px' src=\'cid:" + rscId + "\'></body></html>";
        //图片路径，这里要写绝对路径
        String imgPath = "E:\\11.jpg";
        try {
            emailService.sendRichTextMail(to, subject, content, imgPath, rscId);
            System.out.println("发送成功");
        } catch (MessagingException ex) {
            System.out.println("发送失败");
            System.out.println(ex.toString());
        }
    }

    //发送HTML邮件
    @RequestMapping(value = "sendHtml", method = RequestMethod.GET)
    public void SendWithHtml() {
        String to = "test@xxxx.com";
        String subject = "Java发邮件测试";
        String content = "<html><head></head><body><h3>这是html邮件。。。</h3></body></html>";
        try {
            emailService.sendHtmlMail(to, subject, content);
            System.out.println("发送成功");
        } catch (MessagingException ex) {
            System.out.println("发送失败");
            System.out.println(ex.toString());
        }
    }
}

 

在controller中要注意的是，需要把EmailService注入，不能实例化，否则在Service类中@Value()注解会找不到spring.mail.username的值，

原因请参考：https://stackoverflow.com/questions/39047333/spring-boot-value-properties

我的理解是，手动实例化(new)类的实例是JVM做的事情，SpringBoot并没有参与，所以Value注解将被忽略，字段自然取不到值。

还有被注解的字段不能是static，SpringBoot依赖注入不支static的变量注入。原因是Spring依赖注入的底层原理还是利用反射方式来创建对象。而static修饰的字段、变量在JVM加载类的时候就已经创建，存在于方法区，是类的属性而不是对象的属性，Spring是基于对象层面的依赖注入。