Java实现发邮件功能

前言

电子邮件的应用场景非常广泛，例如新用户加入，即时发送优惠清单、通过邮件找回密码、监听后台程序，出现异常自动邮件通知等。

本文以网易邮箱为例，通过Java代码实现发送邮件功能。

开发环境

请参照: 基于SpringBoot构建分模块项目

代码

1. pom.xml引入依赖

   <properties><java.version>1.8</java.version><!-- 你的其他依赖... --><javax.mail.version>1.6.0</javax.mail.version>
   </properties><dependencies><!-- 你的其他依赖... --><!-- 发送短信 --><dependency><groupId>com.sun.mail</groupId><artifactId>javax.mail</artifactId><version>${javax.mail.version}</version></dependency>
   </dependencies>

2. 发送邮件工具类

   package com.wayne.common.utils;import com.wayne.common.entity.CmsMailConfig;
   import com.wayne.common.vo.MailVo;
   import org.springframework.beans.factory.annotation.Autowired;
   import org.springframework.stereotype.Component;import javax.mail.*;
   import javax.mail.internet.InternetAddress;
   import javax.mail.internet.MimeMessage;
   import java.util.Date;
   import java.util.Properties;/*** 发送邮件工具类* @author Wayne* @date 2019/6/19*/
   @Component
   public class MailUtils {/*** 发送邮件* @param isSingle 是否单发: true-单发 false-群发* @param mailVo 邮件内容* @param sendTime 发送时间, 如果为null，表示立即发送* @param mailConfig 发件人信息及授权*/public void sendMail(Boolean isSingle, MailVo mailVo, Date sendTime, CmsMailConfig mailConfig) throws MessagingException {Session session = this.authenticationMail();MimeMessage message = getMimeMessage(isSingle, session, mailConfig.getMailAccount(), mailVo.getRecipients());message = getContent(message, mailVo.getMailTiTle(), mailVo.getMailContent(), sendTime);Transport transport = session.getTransport();transport.connect(mailConfig.getMailAccount(), mailConfig.getMailLicense());transport.sendMessage(message, message.getAllRecipients());transport.close();}/*** 校验发送的邮件内容*/private MimeMessage getContent(MimeMessage message, String messageTitle, String messageContent, Date sendTime) throws MessagingException {if (null == messageTitle) {throw new MessagingException("邮件标题不能为空");}if (null == messageContent) {throw new MessagingException("邮件内容不能为空");}sendTime = sendTime == null ? new Date() : sendTime;message.setSubject(messageTitle, "UTF-8");message.setContent(messageContent, "text/html;charset=UTF-8");message.setSentDate(sendTime);return message;}/*** 验证认证信息*/private Session authenticationMail() throws MessagingException {Session session;try {Properties props = new Properties();//设置用户的认证方式props.setProperty("mail.smtp.auth", "true");//设置传输协议props.setProperty("mail.transport.protocol", "smtp");//设置发件人的SMTP服务器地址props.setProperty("mail.smtp.host", "smtp.163.com");session = Session.getInstance(props);session.setDebug(true);} catch (Exception e) {e.printStackTrace();throw new MessagingException("认证失败");}return session;}/*** @param isSingle 是否单发*                 <P>true-向指定的一个收件人发送邮件，比如:找回密码、登录验证*                 <P>false-向多个收件人群发邮件，比如:优惠活动推送*                 <P>群发时多个收件人之间用英文逗号','分割* @param senderAddress 发件人地址* @param recipientAddress 收件人地址*/private MimeMessage getMimeMessage(Boolean isSingle, Session session, String senderAddress, String recipientAddress) throws MessagingException {MimeMessage message = new MimeMessage(session);try {message.setFrom(new InternetAddress(senderAddress));} catch (MessagingException e) {throw new MessagingException("发件人地址错误");}/*设置收件人地址MimeMessage.RecipientType.TO:发送MimeMessage.RecipientType.CC：抄送MimeMessage.RecipientType.BCC：密送*/if (isSingle) {message.setRecipient(MimeMessage.RecipientType.TO, new InternetAddress(recipientAddress));} else {message.setRecipients(Message.RecipientType.TO, InternetAddress.parse(recipientAddress));}return message;}
   }

3. 邮件内容对象-MailVo

   package com.wayne.common.vo;import lombok.Data;/*** @author Wayne* @date 2019/6/24*/
   @Data
   public class MailVo {/*** 邮件标题*/private String mailTiTle;/*** 邮件内容*/private String mailContent;/*** 收件人(们)*/private String recipients;
   }

4. 发件人信息及授权

   注: 此处我假定有多个发件人，且不确定，可以动态添加、选择由哪个发件人发送，因此我将发件人信息存储在数据库中。假如你的应用中发件人是固定的，则此处可写在项目中或配在配置文件！

   我们正常发送邮件时需要输入密码，登录我们的邮箱账户。而通过程序发送邮件不需要密码登录，而是使用授权码，网易邮箱授权码获得方式如下

   1. 启用授权

   

   1. 获得授权码

   

   package com.wayne.common.entity;import lombok.Data;import javax.persistence.*;@Data
   @Table(name = "cms_mail_config")
   public class CmsMailConfig {/*** 主键*/@Id@Column(name = "MAIL_ID")private Integer mailId;/*** 邮箱账号*/@Column(name = "MAIL_ACCOUNT")private String mailAccount;/*** 授权码*/@Column(name = "MAIL_LICENSE")private String mailLicense;/*** 状态，0：使用，1：未使用*/@Column(name = "IS_USE")private String isUse;/*** 是否删除，0：否，1：是*/@Column(name = "IS_DELETE")private String isDelete;/*** 创建者ID*/@Column(name = "CREATE_ADMIN_ID")private Integer createAdminId;@Column(name = "EXTEND1")private String extend1;@Column(name = "EXTEND2")private String extend2;@Column(name = "EXTEND3")private String extend3;@Column(name = "EXTEND4")private String extend4;@Column(name = "EXTEND5")private String extend5;@Column(name = "EXTEND6")private String extend6;
   }

5. Service

   @Override
   public ResponseBean sendMails(MailVo mailVo) {if (null == mailVo) {return ResponseBean.createInstance(Boolean.FALSE, 400, "参数异常");}// 获取当前正在使用的发件人配置List<CmsMailConfig> mailConfigList = mailConfigMapper.selectCurrUseMailConfig();if (null == mailConfigList || mailConfigList.size() != 1) {return ResponseBean.createInstance(Boolean.FALSE, 400, "参数异常");}try {// 发送邮件mailUtils.sendMail(Boolean.FALSE, mailVo, null, mailConfigList.get(0));return ResponseBean.createInstance();} catch (Exception e) {e.printStackTrace();}return ResponseBean.createInstance(Boolean.FALSE, 400, "参数异常");
   }

6. Controller

   @PostMapping("/mail/sendMails")
   public ResponseBean sendMails(MailVo mailVo) {return mailService.sendMails(mailVo);
   }

效果

此处发送为手动发送，主要体验代码功能。具体应用场景可根据实际生产环境，随机应变。比如：通过结合定时器任务，每天定时发送报表；检测用户登录地址不是常用地址时，自动发邮件通知用户；普通用户登录时，触发发送邮件向管理员等

结束语

本人已开通公众号，欢迎大家前来灌水