SpringBoot 教程之发送邮件

目录

  1. 简介
  2. API
  3. 配置
  4. 实战
  5. 示例源码
  6. 参考资料

1. 简介

Spring Boot 收发邮件最简便方式是通过 spring-boot-starter-mail。

<dependency>
  <groupId>org.springframework.bootgroupId> <artifactId>spring-boot-starter-mailartifactId> dependency>

spring-boot-starter-mail 本质上是使用 JavaMail(javax.mail)。如果想对 JavaMail 有进一步了解，可以参考： JavaMail 使用指南

2. API

Spring Framework 提供了一个使用 JavaMailSender 接口发送电子邮件的简单抽象，这是发送邮件的核心 API。

JavaMailSender 接口提供的 API 如下：

3. 配置

Spring Boot 为 JavaMailSender 提供了自动配置以及启动器模块。

如果 spring.mail.host 和相关库（由 spring-boot-starter-mail 定义）可用，则 Spring Boot 会创建默认 JavaMailSender（如果不存在）。可以通过 spring.mail 命名空间中的配置项进一步自定义发件人。
特别是，某些默认超时值是无限的，您可能希望更改它以避免线程被无响应的邮件服务器阻塞，如以下示例所示：

spring.mail.properties.mail.smtp.connectiontimeout=5000
spring.mail.properties.mail.smtp.timeout=3000
spring.mail.properties.mail.smtp.writetimeout=5000

也可以使用 JNDI 中的现有会话配置 JavaMailSender：

spring.mail.jndi-name=mail/Session

以下为 Spring Boot 关于 Mail 的配置：

有关更多详细信息，请参阅 MailProperties。

# Email (MailProperties)
spring.mail.default-encoding=UTF-8 # Default MimeMessage encoding.
spring.mail.host= # SMTP server host. For instance, `smtp.example.com`. spring.mail.jndi-name= # Session JNDI name. When set, takes precedence over other Session settings. spring.mail.password= # Login password of the SMTP server. spring.mail.port= # SMTP server port. spring.mail.properties.*= # Additional JavaMail Session properties. spring.mail.protocol=smtp # Protocol used by the SMTP server. spring.mail.test-connection=false # Whether to test that the mail server is available on startup. spring.mail.username= # Login user of the SMTP server.

4. 实战

4.1. 引入依赖

<dependencies>
  <dependency>
    <groupId>org.springframework.bootgroupId> <artifactId>spring-boot-starter-mailartifactId> dependency> <dependency> <groupId>org.springframework.bootgroupId> <artifactId>spring-boot-starter-testartifactId> <scope>testscope> dependency> <dependency> <groupId>org.projectlombokgroupId> <artifactId>lombokartifactId> dependency> <dependency> <groupId>com.github.dozermappergroupId> <artifactId>dozer-spring-boot-starterartifactId> <version>6.4.0version> dependency> dependencies>

4.2. 配置邮件属性

在 src/main/resources 目录下添加 application-163.properties 配置文件，内容如下：

spring.mail.host = smtp.163.com
spring.mail.username = xxxxxx
spring.mail.password = xxxxxx
spring.mail.properties.mail.smtp.auth = true
spring.mail.properties.mail.smtp.starttls.enable = true
spring.mail.properties.mail.smtp.starttls.required = true
spring.mail.default-encoding = UTF-8 mail.domain = 163.com mail.from = ${spring.mail.username}@${mail.domain}

注：需替换有效的 spring.mail.username、spring.mail.password。

application-163.properties 配置文件表示使用 163 邮箱时的配置，为了使之生效，需要通过 spring.profiles.active = 163 来激活它。

在 src/main/resources 目录下添加 application.properties 配置文件，内容如下：

spring.profiles.active = 163

4.3. Java 代码

首先，需要读取部分配置属性，方法如下：

import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.stereotype.Component;
import org.springframework.validation.annotation.Validated;

@Validated
@Component @ConfigurationProperties(prefix = "mail") public class MailProperties { private String domain; private String from; public String getDomain() { return domain; } public void setDomain(String domain) { this.domain = domain; } public String getFrom() { return from; } public void setFrom(String from) { this.from = from; } }

接着，定义一个邮件参数实体类（使用 lombok 简化了 getter、setter）：

import lombok.Data;
import java.util.Date;

@Data
public class MailDTO { private String from; private String replyTo; private String[] to; private String[] cc; private String[] bcc; private Date sentDate; private String subject; private String text; private String[] filenames; }

接着，实现发送邮件的功能接口：

import com.github.dozermapper.core.Mapper;
import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired; 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.MimeBodyPart; import javax.mail.internet.MimeMessage; import javax.mail.internet.MimeMultipart; import java.io.IOException; @Service public class MailService { private final Logger log = LoggerFactory.getLogger(this.getClass()); @Autowired private MailProperties mailProperties; @Autowired private JavaMailSender javaMailSender; @Autowired private Mapper mapper; public void sendSimpleMailMessage(MailDTO mailDTO) { SimpleMailMessage simpleMailMessage = mapper.map(mailDTO, SimpleMailMessage.class); if (StringUtils.isEmpty(mailDTO.getFrom())) { mailDTO.setFrom(mailProperties.getFrom()); } javaMailSender.send(simpleMailMessage); } public void sendMimeMessage(MailDTO mailDTO) { MimeMessage mimeMessage = javaMailSender.createMimeMessage(); MimeMessageHelper messageHelper; try { messageHelper = new MimeMessageHelper(mimeMessage, true); if (StringUtils.isEmpty(mailDTO.getFrom())) { messageHelper.setFrom(mailProperties.getFrom()); } messageHelper.setTo(mailDTO.getTo()); messageHelper.setSubject(mailDTO.getSubject()); mimeMessage = messageHelper.getMimeMessage(); MimeBodyPart mimeBodyPart = new MimeBodyPart(); mimeBodyPart.setContent(mailDTO.getText(), "text/html;charset=UTF-8"); // 描述数据关系 MimeMultipart mm = new MimeMultipart(); mm.setSubType("related"); mm.addBodyPart(mimeBodyPart); // 添加邮件附件 for (String filename : mailDTO.getFilenames()) { MimeBodyPart attachPart = new MimeBodyPart(); try { attachPart.attachFile(filename); } catch (IOException e) { e.printStackTrace(); } mm.addBodyPart(attachPart); } mimeMessage.setContent(mm); mimeMessage.saveChanges(); } catch (MessagingException e) { e.printStackTrace(); } javaMailSender.send(mimeMessage); } }

5. 示例源码

示例源码：spring-boot-mail

6. 参考资料

• Spring Boot 官方文档之 Sending Email