import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;

import java.util.concurrent.ThreadPoolExecutor;

@Configuration
public class AsyncThreadPoolConfig {

    // 核心线程数（默认线程数）
    private static final int corePoolSize = 20;
    // 最大线程数
    private static final int maxPoolSize = 100;
    // 允许线程空闲时间（单位：默认为秒）
    private static final int keepAliveTime = 10;
    // 缓冲队列大小
    private static final int queueCapacity = 200;
    // 线程池名前缀
    private static final String threadNamePrefix = "Async-Service-";

    @Bean("myTaskExecutor")
    public ThreadPoolTaskExecutor myTaskExecutor() {
        ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
        executor.setCorePoolSize(corePoolSize);
        executor.setMaxPoolSize(maxPoolSize);
        executor.setQueueCapacity(queueCapacity);
        executor.setKeepAliveSeconds(keepAliveTime);
        executor.setThreadNamePrefix(threadNamePrefix);
        // 设置线程池关闭的时候等待所有任务都完成再继续销毁其他的Bean
        executor.setWaitForTasksToCompleteOnShutdown(true);
        // 设置线程池中任务的等待时间，如果超过这个时候还没有销毁就强制销毁，以确保应用最后能够被关闭，而不是阻塞住.
        executor.setAwaitTerminationSeconds(60);
        // 线程池对拒绝任务的处理策略
        // CallerRunsPolicy：由调用线程（提交任务的线程）处理该任务
        executor.setRejectedExecutionHandler(new ThreadPoolExecutor.CallerRunsPolicy());
        // 初始化
        executor.initialize();
        return executor;
    }
}