maven依赖包如下
<dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-mail</artifactId></dependency><!-- javax.mail --><dependency><groupId>com.sun.mail</groupId><artifactId>javax.mail</artifactId><version>1.6.0</version></dependency>
一、登录QQ邮箱，点击【设置】后再点击【账户】，再往下翻，找到【POP3/IMAP/SMTP/Exchange/CardDAV/CalDAV服务】这一栏
开启如图所示中的三项（非强制，这三项是根据需要开通的），我这里要求开启第一个
注意图中圈出的【生成授权码】，点击后可以生成一个授权码，然后记录它，待会项目中配置需要
二、在配置文件【application.yml】写好配置，我的配置文件区分了环境(大家可以无视)，默认的应该是application.yml
参数说明：【host】、【port】、【debug】默认配置就好了，debug的话生产建议关掉，【username】是你的QQ邮箱号，【password】是你刚才申请的授权码
三、在代码中建立一个Configuration，用来加载刚才在 application.yml 中配置的数据。这里特别提一下，我采用@Bean的方式注入 JavaMailSenderImpl，在后面用的时候直接以 @Autowired 注入该类
package cn.xt.app.base.config;import org.springframework.beans.factory.annotation.Value;import org.springframework.context.annotation.Bean;import org.springframework.context.annotation.Configuration;import org.springframework.mail.javamail.JavaMailSenderImpl;import java.util.Properties;/*** create: xiaotian* date: /10/20*/@Configurationpublic class MailConfig {@Value("${mail.host}")private String mailHost;@Value("${mail.port}")private Integer mailPort;@Value("${mail.debug}")private String mailDebug;@Value("${mail.username}")private String mailUsername;@Value("${mail.password}")private String mailPassword;@Bean(name = "javaMailSender")public JavaMailSenderImpl javaMailSender(){// 默认配置相关JavaMailSenderImpl javaMailSender = new JavaMailSenderImpl();javaMailSender.setHost(mailHost);javaMailSender.setPort(mailPort);javaMailSender.setUsername(mailUsername);javaMailSender.setPassword(mailPassword);// 认证相关Properties properties = new Properties();properties.setProperty("mail.host", mailHost);properties.setProperty("mail.transport.protocol", "smtp");properties.setProperty("mail.smtp.auth", "true");properties.setProperty("mail.smtp.port", String.valueOf(mailPort));properties.setProperty("mail.smtp.socketFactory.port", String.valueOf(mailPort));properties.setProperty("mail.smtp.socketFactory.class", ".ssl.SSLSocketFactory");javaMailSender.setJavaMailProperties(properties);return javaMailSender;}}
四、接下来编写一个接口，我这里叫【MailBiz】，主要是定义一些使用的方法，例如有的可以发附件，有的方法可以抄送等等
package cn.xt.app.biz.mail;import java.util.List;/*** create: xiaotian* date: /10/20*/public interface MailBiz {void sendMail(String subject, String body, String from, String[] to) throws Exception;void sendMail(String subject, String body, String from, String[] cc, String[] to) throws Exception;void sendMail(String subject, String body, boolean html, String from, String[] cc, String[] to) throws Exception;void sendMail(String subject, String body, boolean html, String from, String[] cc, String[] to, List<String> attachPathList) throws Exception;}
五、接下来定义一个实现类【MailBizService】来实现【MailBiz】这个接口
package cn.xt.app.service.mail;import cn.xt.app.biz.mail.MailBiz;import lombok.extern.slf4j.Slf4j;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.mail.javamail.JavaMailSenderImpl;import org.springframework.mail.javamail.MimeMessageHelper;import org.springframework.stereotype.Service;import org.springframework.util.CollectionUtils;import org.springframework.util.StringUtils;import javax.activation.DataHandler;import javax.activation.FileDataSource;import javax.mail.Multipart;import javax.mail.internet.InternetAddress;import javax.mail.internet.MimeBodyPart;import javax.mail.internet.MimeMessage;import javax.mail.internet.MimeMultipart;import java.util.Date;import java.util.List;/*** create: xiaotian* date: /10/20*/@Slf4j@Servicepublic class MailBizService implements MailBiz {@Autowiredprivate JavaMailSenderImpl javaMailSender;/*** 发送邮件** @param subject 主题* @param body 内容* @param from 发件人* @param to收件人[多个]*/public void sendMail(String subject, String body, String from, String[] to) throws Exception {sendMail(subject, body, from, null, to);}/*** 发送邮件** @param subject 主题* @param body 内容* @param from 发件人* @param cc抄送人[多个]* @param to收件人[多个]*/public void sendMail(String subject, String body, String from, String[] cc, String[] to) throws Exception {sendMail(subject, body, false, from, cc, to);}/*** 发送邮件** @param subject 主题* @param body 内容* @param html 是否为html格式* @param from 发件人* @param cc抄送人[多个]* @param to收件人[多个]*/public void sendMail(String subject, String body, boolean html, String from, String[] cc, String[] to) throws Exception {sendMail(subject, body, html, from, cc, to, null);}/*** 发送邮件** @param subject 主题* @param body 内容* @param html 是否为html格式* @param from 发件人* @param cc 抄送人[多个]* @param to 收件人[多个]* @param attachPathList 附件路径*/public void sendMail(String subject, String body, boolean html, String from, String[] cc, String[] to, List<String> attachPathList) throws Exception {try {MimeMessage parentMimeMessage = javaMailSender.createMimeMessage();MimeMessageHelper mimeMessageHelper = new MimeMessageHelper(parentMimeMessage, true, "utf-8");mimeMessageHelper.setSubject(subject);mimeMessageHelper.setFrom(new InternetAddress(from));mimeMessageHelper.setSentDate(new Date());// 设置收件人地址mimeMessageHelper.setTo(to);// 设置抄送人if (!StringUtils.isEmpty(cc)) {mimeMessageHelper.setCc(cc);}// 设置正文mimeMessageHelper.setText(body, html);// 设置附件if (!CollectionUtils.isEmpty(attachPathList)) {Multipart multipart = new MimeMultipart();for (String attachPath : attachPathList) {MimeBodyPart mimeBodyPart = new MimeBodyPart();DataHandler dataHandler = new DataHandler(new FileDataSource(attachPath));mimeBodyPart.setDataHandler(dataHandler);mimeBodyPart.setFileName(dataHandler.getName());multipart.addBodyPart(mimeBodyPart);}parentMimeMessage.setContent(multipart);}// 正式发送邮件javaMailSender.send(parentMimeMessage);} catch (Exception e) {log.error("发送邮件失败：{}", e);throw e;}}}
至此，发送邮件的代码到这里就这完成了，可以写单元测试来看下效果。这些代码都是经过我的严格测试的，功能都是OK的。
我这里发送邮件的代码以供大家参考：
这里特别指出一下：【mailFrom】也就是发件人，必须是你自己的邮箱号
@Autowiredprivate MailBiz mailBiz;@Value("${mail.username}")private String mailFrom;@Overridepublic ResultResponse sendMail(SendEmailRequest request) {ResultResponse response = new ResultResponse();try {mailBiz.sendMail(request.getSubject(), request.getBody(), request.getHtml(), //mailFrom, request.getCc(), request.getTo(), request.getAttachPathList());response.setCode(ApplicationStatusEnum.SUCCESS.getCode());response.setMessage("邮件发送成功");} catch (Exception e) {response.setCode(ApplicationStatusEnum.FAILED.getCode());response.setMessage("邮件发送失败");}return response;}
总结：利用 yml 配置一些参数，比直接写在代码里面灵活，以 @Value 注解把配置文件中的值注入到变量中。另外在Config中以@Bean的方式将一些配置初始化，相当于核心工作交给Spring去管理，不易出错，且比较好维护。
代码中如有不足之处请大家留言指正！
