SpringBoot 邮件发送与异步优化#

基础配置#

1. 引入依赖#

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

2. 配置邮箱参数#

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spring:
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  mail:
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    username: [email protected]
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    password: your-auth-code
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    host: smtp.163.com

密码处填写的是邮箱的 授权码，不是邮箱登录密码。以 163 邮箱为例，需要在设置 → POP3/SMTP/IMAP 中开启服务并获取授权码。

3. 发送简单邮件#

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@RestController
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@RequiredArgsConstructor
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public class EmailController {
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    private final JavaMailSender javaMailSender;
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    @GetMapping("/send-email")
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    public String sendEmail(String email) {
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        SimpleMailMessage message = new SimpleMailMessage();
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        message.setFrom("your-name<[email protected]>");
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        message.setTo(email);
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        message.setSubject("验证码");
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        message.setText("您的验证码是：123456");
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        javaMailSender.send(message);
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        return "ok";
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    }
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}

使用 @Async 实现异步发送#

同步发送邮件会阻塞请求线程，高并发场景下推荐异步化。

1. 开启异步支持#

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@SpringBootApplication
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@EnableAsync
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public class Application {
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    public static void main(String[] args) {
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        SpringApplication.run(Application.class, args);
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    }
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}

2. 异步发送服务#

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@Component
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@Slf4j
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public class EmailService {
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    @Autowired
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    private JavaMailSender javaMailSender;
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    @Autowired
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    private StringRedisTemplate stringRedisTemplate;
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    @Async
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    public void sendVerificationCode(String email) {
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        String code = UUID.randomUUID().toString().substring(0, 6);
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        SimpleMailMessage message = new SimpleMailMessage();
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        message.setFrom("your-name<[email protected]>");
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        message.setTo(email);
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        message.setSubject("验证码");
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        message.setText(code);
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        stringRedisTemplate.boundValueOps("code:" + email)
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            .set(code, 5, TimeUnit.MINUTES);
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        javaMailSender.send(message);
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        log.info("Verification code sent to: {}", email);
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    }
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}

3. 自定义线程池#

默认的异步线程池核心线程数为 8，可根据业务调整：

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spring:
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  task:
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    execution:
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      pool:
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        core-size: 50

或通过 Java 配置：

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@Bean
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public ThreadPoolTaskExecutor threadPoolExecutor() {
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    ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
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    executor.setCorePoolSize(20);
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    executor.setMaxPoolSize(50);
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    executor.setQueueCapacity(200);
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    executor.setThreadNamePrefix("mail-executor-");
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    executor.initialize();
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    return executor;
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}