springboot 异步邮件服务

目标：springboot，使用异步方式后台发送邮件。

关键点：异步服务不能在同类里调用。

1、mail依赖

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

2、yml配置

spring:
  mail:
    host: smtp.126.com
    port: 25
    username: abc99@126.com
    password: HXAABBCCBEJLSYPQ
    properties:
      mail:
        debug: false

username：发件人邮件地址，

password：发件人邮箱密码或者授权码

3、代码实现

3.1 线程池准备

@Configuration
@EnableAsync
public class ThreadPoolConfig {
    @Bean("messageThread")
    public TaskExecutor taskExecutor() {
        ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
        // 设置核心线程数
        executor.setCorePoolSize(4);
        // 设置最大线程数
        executor.setMaxPoolSize(8);
        // 设置队列容量
        executor.setQueueCapacity(100);
        // 设置线程活跃时间（秒）
        executor.setKeepAliveSeconds(60);
        // 设置默认线程名称
        executor.setThreadNamePrefix("com.wood.message-");
        // 设置拒绝策略
        executor.setRejectedExecutionHandler(new ThreadPoolExecutor.CallerRunsPolicy());
        // 等待所有任务结束后再关闭线程池
        executor.setWaitForTasksToCompleteOnShutdown(true);
        executor.setAwaitTerminationSeconds(60);
        return executor;
    }
}

3.2 邮件服务

@Slf4j
@Service
public class MailServiceImpl implements MailService {

    @Resource
    private JavaMailSender javaMailSender;

    @Value("${spring.mail.username}")
    private String sender;

    @Override
    @Async("messageThread") //对应线程池的bean，使用线程池实现异步调用
    public void sendMail(List<SysUser> receivers, String subject, String content) {
        // 获取收件人邮件地址数组
        String[] receiverMails = receivers.stream().map(SysUser::getEmail).filter(StringUtils::isNotBlank).distinct().toArray(String[]::new);
        if(receiverMails.length<1) return;
        SimpleMailMessage message = new SimpleMailMessage();
        // 邮件主题
        message.setSubject(subject);
        // 发件人
        message.setFrom("邮件提醒<"+sender+">");
   　　　// 收件人数组　
        message.setTo(receiverMails);
        // 发送日期
        message.setSentDate(new Date());
        // 正文
        message.setText(content);

        javaMailSender.send(message);
        log.info("邮件提醒，收件人："+ Arrays.toString(receiverMails)+",内容："+content);
    }
}