springboot 线程池的使用

超、凢脫俗 2022-04-13 07:51 242阅读 0赞

线程池可以用于解决单线程干某件事情比较慢的问题

> AsyncConfigurer：通过实现AsyncConfigurer自定义线程池，包含异常处理  
> 实现AsyncConfigurer接口对异常线程池更加细粒度的控制

步骤：\*  
a) 创建线程自己的线程池  
b) 对void方法抛出的异常处理的类AsyncUncaughtExceptionHandler

demo

import org.springframework.aop.interceptor.AsyncUncaughtExceptionHandler;
    import org.springframework.context.annotation.Bean;
    import org.springframework.context.annotation.ComponentScan;
    import org.springframework.context.annotation.Configuration;
    import org.springframework.context.annotation.PropertySource;
    import org.springframework.scheduling.annotation.AsyncConfigurer;
    import org.springframework.scheduling.annotation.EnableAsync;
    import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;
    import java.lang.reflect.Method;
    import java.util.concurrent.Executor;
    import java.util.concurrent.ThreadPoolExecutor;
    
    /** * @author * @version 1.0 * <p> * 配置类实现AsyncConfigurer接口并重写getAsyncExecutor方法，并返回ThreadPoolTaskExecutor， * 这样我们就获得了一个基于线程池TaskExecutor */
    @Configuration
    @ComponentScan("com.demo") //扫描一定要包含执行类
    @EnableAsync
    @PropertySource(value = "classpath:application.properties", ignoreResourceNotFound = true)//手动配置目录，解决property配置找不到的问题
    public class ThreadConfig implements AsyncConfigurer { 
    
        @Override
        public Executor getAsyncExecutor() { 
            ThreadPoolTaskExecutor taskExecutor = new ThreadPoolTaskExecutor();
            //核心线程数
            taskExecutor.setCorePoolSize(20);
            //队列最大长度
            taskExecutor.setQueueCapacity(1000);
            //最大线程数
            taskExecutor.setMaxPoolSize(50);
            //线程池维护线程所允许的空闲时间(单位秒)
            taskExecutor.setKeepAliveSeconds(10);
            //设置名称
            taskExecutor.setThreadNamePrefix("demo-thread");
            /* * 线程池对拒绝任务(无线程可用)的处理策略 * ThreadPoolExecutor.CallerRunsPolicy策略,调用者的线程会执行该任务,如果执行器已关闭,则丢弃. */
            taskExecutor.setRejectedExecutionHandler(new ThreadPoolExecutor.AbortPolicy());
    
            taskExecutor.initialize();
            return taskExecutor;
        }
        @Override
        public AsyncUncaughtExceptionHandler getAsyncUncaughtExceptionHandler() { 
            return new SpringAsyncExceptionHandler();
        }
        class SpringAsyncExceptionHandler implements AsyncUncaughtExceptionHandler { 
            @Override
            public void handleUncaughtException(Throwable throwable, Method method, Object... objects) { 
                System.out.println("线程池错误！" + throwable.getMessage());
            }
        }
    }

线程池批量调用待执行任务对任务进行并发执行：

ExecutorService pool = Executors.newFixedThreadPool(webProcessInfo.getMaxThread());
    List<Callable<Integer>> callers = new ArrayList<>();
    callers.add(()->{ 
        crawlParseService.getChildUrls(linkurl, projectId, batchId, baseUrl, webProcessInfo, uncheckedUrlSet);
        return null;
    });
    
    //用线程池来执行callers中的批量任务
    try { 
        pool.invokeAll(callers);
        pool.shutdown();
    }catch (InterruptedException e){ 
        e.printStackTrace();
    }

以上