原文链接：https://blog.csdn.net/qq_37745470/article/details/89094227
什么是SMTP？
SMTP全称为Simple Mail Transfer Protocol（简单邮件传输协议），它是一组用于从源地址到目的地址传输邮件的规范，通过它来控制邮件的中转方式。SMTP认证要求必须提供账号和密码才能登陆服务器，其设计目的在于避免用户受到垃圾邮件的侵扰。
什么是IMAP？
IMAP全称为Internet Message Access Protocol（互联网邮件访问协议），IMAP允许从邮件服务器上获取邮件的信息、下载邮件等。IMAP与POP类似，都是一种邮件获取协议。
什么是POP3？
POP3全称为Post Office Protocol 3（邮局协议），POP3支持客户端远程管理服务器端的邮件。POP3常用于“离线”邮件处理，即允许客户端下载服务器邮件，然后服务器上的邮件将会被删除。目前很多POP3的邮件服务器只提供下载邮件功能，服务器本身并不删除邮件，这种属于改进版的POP3协议。
JavaMailSender接口、JavaMailSenderImpl实现类
//注入JavaMailSenderImpl实现类
@Autowired
private JavaMailSenderImpl mailSender;
//简单邮件SimpleMailMessage
SimpleMailMessage simpleMailMessage = new SimpleMailMessage();
simpleMailMessage.setFrom("2708169628@qq.com");
simpleMailMessage.setTo("2708169628@qq.com");
simpleMailMessage.setSubject("尝试发送邮件");
simpleMailMessage.setText("一杯茶，一根烟，一个Bug改一天");
mailSender.send(simpleMailMessage);
//复杂邮件MimeMessage
MimeMessage mimeMessage = mailSender.createMimeMessage();
MimeMessageHelper messageHelper = new MimeMessageHelper(mimeMessage);
messageHelper.setFrom("2708169628@qq.com");
messageHelper.setTo("2708169628@qq.com");
messageHelper.setSubject("尝试发送附件");
messageHelper.setText("一杯茶，一根烟，一个Bug改一天！");
messageHelper.addInline("login.png", new File("login.png"));
messageHelper.addAttachment("work.docx", new File("work.docx"));
mailSender.send(mimeMessage);
MailSenderPropertiesConfiguration 自动配置类
@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;
}
MailProperties 参数配置
@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<>();
}
开启QQ邮箱的POP3、SMTP、IMAP协议，生成授权码
# tomcat port
server.port=8088
# thymeleaf
spring.thymeleaf.prefix=classpath:/templates/
spring.thymeleaf.check-template-location=true
spring.thymeleaf.mode=HTML
spring.thymeleaf.suffix=.html
spring.thymeleaf.encoding=UTF-8
spring.thymeleaf.cache=false
#email
spring.mail.host=smtp.qq.com
spring.mail.username=2708169628@qq.com
spring.mail.password=mhilempuoluhdeja#授权码
spring.mail.port=465
#设置为SSL协议
spring.mail.properties.mail.smtp.socketFactory.class=javax.net.ssl.SSLSocketFactory
spring.mail.properties.from=liuy.yang@qq.com
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<body>
<form action="http://127.0.0.1:8088/mail/send" method="post" accept-charset="UTF-8" enctype="multipart/form-data" name="mailVo">
收件人<input type="email" name="from"/>
发件人<input type="email" name="to"/>
主题<input type="text" name="subject"/>
正文<input type="text" name="text"/>
附件 <input type="file" name="file" multiple/>
<input type="submit">
</form>
</body>
</html>
@Data
public class MailVO {
private String id;//邮件id
private String from;//邮件发送人
private String to;//邮件接收人
private String subject;//邮件主题
private String text;//邮件内容
private Date sentDate;//发送时间
private String cc; //抄送
private String bcc; //密送
private String status; //状态
private String error; //报错信息
private MultipartFile[] multipartFiles;//邮件附件
}
package com.liu.mail.service;
import com.liu.mail.vo.MailVO;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpRequest;
import org.springframework.mail.javamail.JavaMailSenderImpl;
import org.springframework.mail.javamail.MimeMessageHelper;
import org.springframework.scheduling.annotation.Async;
import org.springframework.stereotype.Service;
import org.springframework.util.StringUtils;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.multipart.MultipartFile;
import org.springframework.web.multipart.MultipartHttpServletRequest;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.Part;
import java.util.Collection;
import java.util.Date;
import java.util.List;
import java.util.Map;
/**
* MailServiceImpl
*
* @author liuy
* @data 2021/10/5 10:47
**/
@Service
@RequestMapping("/mail")
public class MailServiceImpl {
@Autowired
JavaMailSenderImpl mailSender;
@PostMapping("/send")
public MailVO send(MailVO mailVo, HttpServletRequest request){
try {
MultipartHttpServletRequest multipartHttpServletRequest= (MultipartHttpServletRequest) request;
//获取文件集合 name：前端input设置的名字
List<MultipartFile> file = multipartHttpServletRequest.getFiles("file");
MultipartFile[] multipartFiles=file.toArray(new MultipartFile[10]);
mailVo.setMultipartFiles(multipartFiles);
checkMail(mailVo); //1.检测邮件
sendMimeMail(mailVo); //2.发送邮件
return saveMail(mailVo); //3.保存邮件
} catch (Exception e) {
mailVo.setStatus("fail");
mailVo.setError(e.getMessage());
return mailVo;
}
}
/**
* 构建复杂邮件
* @param mailVo
*/
private MailVO sendMimeMail(MailVO mailVo) {
try {
MimeMessageHelper messageHelper = new MimeMessageHelper(mailSender.createMimeMessage(), true);//true表示支持复杂类型
messageHelper.setFrom(mailVo.getFrom());//邮件发信人
messageHelper.setTo(mailVo.getTo().split(","));//邮件收信人
messageHelper.setSubject(mailVo.getSubject());//邮件主题
messageHelper.setText(mailVo.getText());//邮件内容
if (mailVo.getMultipartFiles() != null) {//添加邮件附件
for (MultipartFile multipartFile : mailVo.getMultipartFiles()) {
if (multipartFile==null){
break;
}
messageHelper.addAttachment(multipartFile.getOriginalFilename(), multipartFile);
}
}
if (mailVo.getSentDate()==null) {//发送时间
mailVo.setSentDate(new Date());
messageHelper.setSentDate(mailVo.getSentDate());
}
mailSender.send(messageHelper.getMimeMessage());//正式发送邮件
mailVo.setStatus("ok");
return mailVo;
} catch (Exception e) {
throw new RuntimeException(e);//发送失败
}
}
/**
* 邮件信息检查
* @param mailVO
*/
private void checkMail(MailVO mailVO) {
if (mailVO.getTo()==null) {
throw new RuntimeException("邮件收信人不能为空");
}
if (mailVO.getSubject()==null) {
throw new RuntimeException("邮件主题不能为空");
}
if (mailVO.getText()==null) {
throw new RuntimeException("邮件内容不能为空");
}
}
}