SpringBoot发送Gmail邮件

1. 登录Gmail

Gmail网址
点击右上角“小齿轮”，然后点击"查看所有设置"
在这里插入图片描述
点击“转发和 POP/IMAP”，按图中设置，然后点击保存：

2. 启用两步验证(https://myaccount.google.com/security)

登录上述网址，找到“安全”（Security）
点击“两步验证”

开启“两步验证”，小编这里已经开启了，所以显示的关闭.

3. 创建应用程序密码

搜索"App passwords"，点击第一个在这里插入图片描述
输入程序名称，点击“创建”后会显示一个密码，该密码可以用来发送邮件.

4. Java程序实现（方式1）

4.1 导入依赖

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

4.2 yml配置

spring
  mail:
    host: smtp.gmail.com
    port: 587
    username: xxx@gmail.com
    password: xxx # 第三步的应用程序密码
    properties:
      mail:
        smtp:
          auth: true
          starttls:
            enable: true
            required: true

4.3 代码

import jakarta.mail.MessagingException;
import jakarta.mail.internet.MimeMessage;
import lombok.RequiredArgsConstructor;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.mail.SimpleMailMessage;
import org.springframework.mail.javamail.JavaMailSender;
import org.springframework.mail.javamail.MimeMessageHelper;
import org.springframework.stereotype.Service;

/**
 * 邮件发送服务实现类
 */
@Slf4j
@RequiredArgsConstructor
@Service
public class MailSendService {

	@Value("${spring.mail.username}")
	private String mailFrom;
	private final JavaMailSender javaMailSender;

	@Override
	public void sendMailSimple(String to, String subject, String text)  {
		SimpleMailMessage simpleMailMessage = new SimpleMailMessage();
		// 发件人
		simpleMailMessage.setFrom(mailFrom);
		// 收件人
		simpleMailMessage.setTo(to);
		// 邮件主题
		simpleMailMessage.setSubject(subject);
		// 邮件内容
		simpleMailMessage.setText(text);
		javaMailSender.send(simpleMailMessage);
	}

	@Override
	public void sendWithAttach(String to, String subject, String text, MailAttachInfoDTO ...attachInfos) {
		MimeMessage message = javaMailSender.createMimeMessage();
		try{
			MimeMessageHelper helper = new MimeMessageHelper(message, true);
			helper.setFrom(mailFrom);
			helper.setTo(to);
			helper.setSubject(subject);
			helper.setText(text);
			for(MailAttachInfoDTO attachInfo : attachInfos) {
				if(attachInfo == null) continue;
				helper.addAttachment(attachInfo.getAttachName(), attachInfo.getAttachSource());
			}
		}catch (MessagingException e) {
			log.warn("MailSendServiceImpl.sendWithAttach failed.", e);
		}
		javaMailSender.send(message);
	}
}

4.4 设置代理

在调试的时候需要梯子，否则可能访问不了Gmail的服务器：

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.data.jpa.repository.config.EnableJpaAuditing;
import org.springframework.scheduling.annotation.EnableScheduling;

@EnableScheduling
@EnableJpaAuditing
@SpringBootApplication
public class TestApplication {

	public static void main(String[] args) {
		// 设置代理地址、端口		你们调试的时候替换成自己的代理地址端口
		System.setProperty("http.proxyHost", "192.168.0.12");
		System.setProperty("http.proxyPort", "10183");
		SpringApplication.run(TestApplication.class, args);
	}

}

5. Java程序实现（方式2-动态发送者）

由于我们项目中，原本已经存在发送邮件的功能，yml已经配置了其他的邮箱，而此时又来一个新需求，需要使用不同的邮箱来发送。所以这里我使用了动态设置发送人的方式。

DynamicMailSender.java

import org.springframework.mail.javamail.JavaMailSender;
import org.springframework.mail.javamail.JavaMailSenderImpl;

import java.util.Properties;

public class DynamicMailSender {

    public static JavaMailSender createGmailSender(String username, String password) {
        JavaMailSenderImpl mailSender = new JavaMailSenderImpl();
        mailSender.setHost("smtp.gmail.com");
        mailSender.setPort(587);
        mailSender.setUsername(username);
        mailSender.setPassword(password);

        Properties props = mailSender.getJavaMailProperties();
        props.put("mail.transport.protocol", "smtp");
        props.put("mail.smtp.auth", "true");
        props.put("mail.smtp.starttls.enable", "true");
//        props.put("mail.smtp.connectiontimeout", "5000");
//        props.put("mail.smtp.timeout", "5000");
//        props.put("mail.smtp.writetimeout", "5000");
        props.put("mail.debug", "true");

        return mailSender;
    }
}

EmailService.java

import jakarta.mail.internet.MimeMessage;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.lang3.StringUtils;
import org.springframework.mail.SimpleMailMessage;
import org.springframework.mail.javamail.JavaMailSender;
import org.springframework.mail.javamail.MimeMessageHelper;
import org.springframework.stereotype.Service;

@Slf4j
@Service
public class EmailService {
	
	/**
     * 发送Gmail邮件
     * @param from 发送者邮箱
     * @param password 应用程序密码
     * @param to 接收者邮箱
     * @param subject 邮件主题
     * @param text 邮件内容
     * @return 发送是否成功
     */
    public boolean sendGmailSimple(String from, String password, String to, String subject, String text) {
        try {
            JavaMailSender mailSender = DynamicMailSender.createGmailSender(from, password);

            SimpleMailMessage message = new SimpleMailMessage();
            message.setFrom(from);
            message.setTo(to);
            message.setSubject(subject);
            message.setText(text);

            mailSender.send(message);
            return true;
        } catch (Exception e) {
            log.info("EmailService 发送gmail失败.", e);
        }
        return false;
    }

	/**
     * 发送Gmail邮件
     * @param fromEmail 发送者邮箱
     * @param fromName 发送者昵称
     * @param password 应用程序密码
     * @param to 接收者邮箱
     * @param subject 邮件主题
     * @param text 邮件内容
     * @return 发送是否成功
     */
    public boolean sendGmailSimple(String fromEmail, String fromName, String password, String to, String subject, String text) {
        if (StringUtils.isBlank(fromName)) {
            return sendGmailSimple(fromEmail, password, to, subject, text);
        }
        return sendGmailSimple(fromEmail, fromName, password, to, subject, text, false);
    }

	/**
     * 发送Gmail邮件
     * @param fromEmail 发送者邮箱
     * @param fromName 发送者昵称
     * @param password 应用程序密码
     * @param to 接收者邮箱
     * @param subject 邮件主题
     * @param text 邮件内容
     * @param html 内容是否使用html格式
     * @return 发送是否成功
     */
    public boolean sendGmailSimple(String fromEmail, String fromName, String password, String to, String subject, String text, boolean html) {
        try {
            JavaMailSender mailSender = DynamicMailSender.createGmailSender(fromEmail, password);
            MimeMessage message = mailSender.createMimeMessage();
            MimeMessageHelper helper = new MimeMessageHelper(message, true);

            helper.setFrom(fromEmail, fromName);
            helper.setTo(to);
            helper.setSubject(subject);
            helper.setText(text, html);

            mailSender.send(message);
            return true;
        } catch (Exception e) {
            log.info("EmailService 发送gmail失败.", e);
        }
        return false;
    }
}