Scheduled线程-schedule

爱被打了一巴掌 2022-07-16 11:17 175阅读 0赞

## schedule ##

## 1.schedule方法 ##

schedule方法主要使用延迟或者定时执行一次，在指定时间之后。

在延迟两秒后提交任务，开始任务的执行

package com.cweeyii.threadpool;
    
    import org.slf4j.Logger;
    import org.slf4j.LoggerFactory;
    
    import java.util.ArrayList;
    import java.util.List;
    import java.util.concurrent.*;
    
    /** * Created by wenyi on 16/10/16. * Email:caowenyi@meituan.com */
    public class ScheduledThreadPool { 
        private static final Logger LOGGER = LoggerFactory.getLogger(ScheduledThreadPool.class);
    
        public static void main(String[] args) throws ExecutionException, InterruptedException {
            testScheduledMethod();
            testFixScheduledMethod();
            testFixWithScheduledMethod();
        }
    
        private static void testScheduledMethod() throws ExecutionException, InterruptedException {
            int poolSize = 2;
            ScheduledExecutorService executorService = Executors.newScheduledThreadPool(poolSize);
            List<Future<CallerHandle>> futureList = new ArrayList<>();
            for (int i = 0; i < poolSize * 2; i++) {
                futureList.add(executorService.schedule(new CallableWorker(), 2, TimeUnit.SECONDS));
            }
            executorService.shutdown();
            LOGGER.info("线程池已经被关闭");
            for (Future<CallerHandle> future : futureList) {
                CallerHandle handle = future.get();
                LOGGER.info(handle.getThreadName() + "已经完成");
            }
            LOGGER.info("主线程结束");
        }
    
        private static void testFixScheduledMethod() throws ExecutionException, InterruptedException {
            int poolSize = 2;
            ScheduledExecutorService executorService = Executors.newScheduledThreadPool(poolSize);
            for (int i = 0; i < poolSize * 2; i++) {
                executorService.scheduleAtFixedRate(new RunableWorker(), 0, 5, TimeUnit.SECONDS);
            }
            executorService.awaitTermination(10, TimeUnit.SECONDS);
            executorService.shutdown();
            LOGGER.info("线程池已经被关闭");
            LOGGER.info("主线程结束");
        }
    
        private static void testFixWithScheduledMethod() throws ExecutionException, InterruptedException {
            int poolSize = 2;
            ScheduledExecutorService executorService = Executors.newScheduledThreadPool(poolSize);
            for (int i = 0; i < poolSize * 2; i++) {
                executorService.scheduleWithFixedDelay(new RunableWorker(), 0, 5, TimeUnit.SECONDS);
            }
            executorService.awaitTermination(10, TimeUnit.SECONDS);
            executorService.shutdown();
            LOGGER.info("线程池已经被关闭");
            LOGGER.info("主线程结束");
        }
    }

testScheduledMethod结果如下：

22:04:41.017  INFO (ScheduledThreadPool.java:29) - 线程池已经被关闭
    22:04:45.023  INFO (CallableWorker.java:20) - pool-1-thread-1 结束任务
    22:04:45.024  INFO (CallableWorker.java:20) - pool-1-thread-2 结束任务
    22:04:45.026  INFO (ScheduledThreadPool.java:32) - pool-1-thread-1已经完成
    22:04:45.027  INFO (ScheduledThreadPool.java:32) - pool-1-thread-2已经完成
    22:04:47.029  INFO (CallableWorker.java:20) - pool-1-thread-1 结束任务
    22:04:47.029  INFO (CallableWorker.java:20) - pool-1-thread-2 结束任务
    22:04:47.029  INFO (ScheduledThreadPool.java:32) - pool-1-thread-1已经完成
    22:04:47.030  INFO (ScheduledThreadPool.java:32) - pool-1-thread-2已经完成
    22:04:47.030  INFO (ScheduledThreadPool.java:34) - 主线程结束

注意：scheduleAtFixedRate只会同时调度指定线程数量的任务,其他的任务执行时间会延后，但是其调度延迟时间是按照任务执行开始时间进行计算。

testFixScheduledMethod执行结果如下：

22:46:37.313  INFO (RunableWorker.java:27) - pool-1-thread-2 线程处理提交任务完成
    22:46:37.313  INFO (RunableWorker.java:27) - pool-1-thread-1 线程处理提交任务完成
    22:46:39.318  INFO (RunableWorker.java:27) - pool-1-thread-2 线程处理提交任务完成
    22:46:39.324  INFO (RunableWorker.java:27) - pool-1-thread-1 线程处理提交任务完成
    22:46:42.316  INFO (RunableWorker.java:27) - pool-1-thread-2 线程处理提交任务完成
    22:46:42.316  INFO (RunableWorker.java:27) - pool-1-thread-1 线程处理提交任务完成
    22:46:44.321  INFO (RunableWorker.java:27) - pool-1-thread-1 线程处理提交任务完成
    22:46:44.321  INFO (RunableWorker.java:27) - pool-1-thread-2 线程处理提交任务完成
    22:46:45.311  INFO (ScheduledThreadPool.java:47) - 线程池已经被关闭
    22:46:45.312  INFO (ScheduledThreadPool.java:48) - 主线程结束
    22:46:47.314  INFO (RunableWorker.java:27) - pool-1-thread-1 线程处理提交任务完成

注意：scheduleWithFixedDelay只会同时调度指定线程数量的任务,其他的任务执行时间会延后，但是其调度延迟时间是按照任务结束时间进行计算。

testFixWithScheduledMethod执行如下：

22:49:50.897  INFO (RunableWorker.java:27) - pool-1-thread-1 线程处理提交任务完成
    22:49:50.897  INFO (RunableWorker.java:27) - pool-1-thread-2 线程处理提交任务完成
    22:49:52.906  INFO (RunableWorker.java:27) - pool-1-thread-1 线程处理提交任务完成
    22:49:52.906  INFO (RunableWorker.java:27) - pool-1-thread-2 线程处理提交任务完成
    22:49:57.907  INFO (RunableWorker.java:27) - pool-1-thread-1 线程处理提交任务完成
    22:49:57.907  INFO (RunableWorker.java:27) - pool-1-thread-2 线程处理提交任务完成
    22:49:58.895  INFO (ScheduledThreadPool.java:59) - 线程池已经被关闭
    22:49:58.896  INFO (ScheduledThreadPool.java:60) - 主线程结束
    22:49:59.911  INFO (RunableWorker.java:27) - pool-1-thread-2 线程处理提交任务完成
    22:49:59.911  INFO (RunableWorker.java:27) - pool-1-thread-1 线程处理提交任务完成