SpringBoot中实现多线程六种方式大全

// 开启异步
@EnableAsync
@SpringBootApplication
public class Application { ... }

// 异步方法
@Service
public class MailService {

    @Async
    public void sendMail(String to, String content) {
        // 耗时操作
        log.info("发送邮件中... Thread: {}", Thread.currentThread().getName());
    }
}

@Configuration
public class AsyncConfig implements AsyncConfigurer {

    @Override
    public Executor getAsyncExecutor() {
        ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
        executor.setCorePoolSize(8);
        executor.setMaxPoolSize(16);
        executor.setQueueCapacity(200);
        executor.setThreadNamePrefix("async-mail-");
        // 拒绝策略（很重要！）
        executor.setRejectedExecutionHandler(new ThreadPoolExecutor.CallerRunsPolicy());
        executor.initialize();
        return executor;
    }

    @Override
    public AsyncUncaughtExceptionHandler getAsyncUncaughtExceptionHandler() {
        return (ex, method, params) -> log.error("异步异常", ex);
    }
}

@Service
public class UserService {

    @Async
    public CompletableFuture<User> getUserById(Long id) {
        // 模拟耗时
        Thread.sleep(1000);
        return CompletableFuture.completedFuture(new User(id));
    }

    public CompletableFuture<List<User>> batchGetUsers(List<Long> ids) {
        List<CompletableFuture<User>> futures = ids.stream()
            .map(this::getUserById)
            .toList();

        return CompletableFuture.allOf(futures.toArray(new CompletableFuture[0]))
            .thenApply(v -> futures.stream().map(CompletableFuture::join).toList());
    }
}

@Autowired
private ThreadPoolTaskExecutor executor;

public void processBatch(List<Task> tasks) {
    List<CompletableFuture<Void>> futures = new ArrayList<>();
    for (Task task : tasks) {
        CompletableFuture<Void> future = CompletableFuture.runAsync(task::execute, executor);
        futures.add(future);
    }
    CompletableFuture.allOf(futures.toArray(new CompletableFuture[0])).join();
}

// 方式1：直接 new Thread（不推荐）
new Thread(() -> doSomething()).start();

// 方式2：Executors 工具类
ExecutorService executor = Executors.newFixedThreadPool(10);
executor.submit(() -> doSomething());

# application.yml
spring:
  threads:
    virtual:
      enabled: true

@Bean
public TaskExecutor taskExecutor() {
    return Executors.newVirtualThreadPerTaskExecutor();
}

@Configuration
@EnableScheduling
@EnableAsync
public class ScheduleConfig {

    @Scheduled(cron = "0 */5 * * * ?")
    @Async("batchExecutor")
    public void processBatchJob() {
        // 批量处理逻辑
    }

    @Bean("batchExecutor")
    public ThreadPoolTaskExecutor batchExecutor() {
        ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
        executor.setCorePoolSize(4);
        executor.setMaxPoolSize(8);
        // ...
        return executor;
    }
}