Java线程的生命周期管理：理解自动终止与异步任务的最佳实践

public Advert saveAdvert(Advert advert) {
    Advert advertToSave = advertRepository.save(advert);

    // 每次调用此方法都会创建一个新的Thread实例
    new Thread(() -> {
        try {
            populateAdvertSearch(advertToSave);
        } catch (ParseException | OfficeNotFoundException | OfficePropertyNotFoundException e) {
            e.printStackTrace();
            // 记录异常或进行其他错误处理
        }
    }).start(); // 启动新线程

    return advertToSave;
}

import java.text.ParseException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import javax.annotation.PostConstruct;
import javax.annotation.PreDestroy;
import org.springframework.stereotype.Service;

@Service
public class AdvertService {

    private final AdvertRepository advertRepository;
    private ExecutorService asyncTaskExecutor; // 声明线程池

    public AdvertService(AdvertRepository advertRepository) {
        this.advertRepository = advertRepository;
    }

    // 在服务初始化时创建线程池
    @PostConstruct
    public void init() {
        // 推荐使用Executors.newFixedThreadPool()或ThreadPoolExecutor自定义线程池
        // 这里使用newCachedThreadPool作为示例，它会根据需要创建新线程，并在空闲60秒后回收
        asyncTaskExecutor = Executors.newCachedThreadPool(); 
        // 也可以使用 Executors.newFixedThreadPool(Runtime.getRuntime().availableProcessors() * 2);
        // 根据CPU核心数设置固定大小的线程池
    }

    public Advert saveAdvert(Advert advert) {
        Advert advertToSave = advertRepository.save(advert);

        // 使用线程池提交任务
        asyncTaskExecutor.submit(() -> {
            try {
                populateAdvertSearch(advertToSave);
            } catch (ParseException | OfficeNotFoundException | OfficePropertyNotFoundException e) {
                e.printStackTrace();
                // 记录异常或进行其他错误处理
            }
        });

        return advertToSave;
    }

    private void populateAdvertSearch(Advert advert) throws ParseException, OfficeNotFoundException, OfficePropertyNotFoundException {
        // 模拟耗时操作
        System.out.println("Executing populateAdvertSearch for Advert ID: " + advert.getId() + " on thread: " + Thread.currentThread().getName());
        try {
            Thread.sleep(2000); // 模拟2秒的耗时操作
        } catch (InterruptedException e) {
            Thread.currentThread().interrupt(); // 重新设置中断状态
            e.printStackTrace();
        }
        System.out.println("Finished populateAdvertSearch for Advert ID: " + advert.getId());
    }

    // 在服务销毁时关闭线程池，释放资源
    @PreDestroy
    public void shutdown() {
        if (asyncTaskExecutor != null && !asyncTaskExecutor.isShutdown()) {
            asyncTaskExecutor.shutdown(); // 启动有序关闭，不再接受新任务，等待已提交任务完成
            try {
                // 等待所有任务完成，最多等待60秒
                if (!asyncTaskExecutor.awaitTermination(60, java.util.concurrent.TimeUnit.SECONDS)) {
                    asyncTaskExecutor.shutdownNow(); // 强制关闭，中断正在执行的任务
                }
            } catch (InterruptedException e) {
                asyncTaskExecutor.shutdownNow(); // 强制关闭
                Thread.currentThread().interrupt(); // 重新设置中断状态
            }
        }
    }

    // 假设的AdvertRepository和Advert类
    static class AdvertRepository {
        public Advert save(Advert advert) {
            System.out.println("Saving advert: " + advert.getId());
            return advert;
        }
    }

    static class Advert {
        private Long id;
        public Advert(Long id) { this.id = id; }
        public Long getId() { return id; }
        public void setId(Long id) { this.id = id; }
    }

    // 假设的异常类
    static class OfficeNotFoundException extends Exception {}
    static class OfficePropertyNotFoundException extends Exception {}
}