jdk线程池的实现

public ThreadPoolExecutor(int corePoolSize,
                              int maximumPoolSize,
                              long keepAliveTime,
                              TimeUnit unit,
                              BlockingQueue<Runnable> workQueue,
                              ThreadFactory threadFactory,
                              RejectedExecutionHandler handler) {
        if (corePoolSize < 0 ||
            maximumPoolSize <= 0 ||
            maximumPoolSize < corePoolSize ||
            keepAliveTime < 0)
            throw new IllegalArgumentException();
        if (workQueue == null || threadFactory == null || handler == null)
            throw new NullPointerException();
        this.acc = System.getSecurityManager() == null ?
                null :
                AccessController.getContext();
        this.corePoolSize = corePoolSize;
        this.maximumPoolSize = maximumPoolSize;
        this.workQueue = workQueue;
        this.keepAliveTime = unit.toNanos(keepAliveTime);
        this.threadFactory = threadFactory;
        this.handler = handler;
    }

ExecutorService pool = Executors.newXXXXXPool()

public static ExecutorService newFixedThreadPool(int nThreads) {
        return new ThreadPoolExecutor(nThreads, nThreads,
                                      0L, TimeUnit.MILLISECONDS,
                                      new LinkedBlockingQueue<Runnable>());
    }

public static ExecutorService newSingleThreadExecutor() {
        return new FinalizableDelegatedExecutorService
            (new ThreadPoolExecutor(1, 1,
                                    0L, TimeUnit.MILLISECONDS,
                                    new LinkedBlockingQueue<Runnable>()));
    }

public static ExecutorService newCachedThreadPool() {
        return new ThreadPoolExecutor(0, Integer.MAX_VALUE,
                                      60L, TimeUnit.SECONDS,
                                      new SynchronousQueue<Runnable>());
    }

package cn.demo;

import cn.hutool.core.util.RandomUtil;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;

public class ExecutorTestsForCallableTask {

    public static void main(String[] args) throws ExecutionException, InterruptedException {
        String res1 = "";
        String res2 = "";
        String res3 = "";
        String res4 = "";

        ExecutorService fixedThreadPool = Executors.newFixedThreadPool(3);

        //submit 提交4个任务, 实际执行时,任务是并发执行的,执行顺序不固定
        Future<String> submit1 = fixedThreadPool.submit(
                new TestCallableTask(RandomUtil.randomInt(30,1000),"t1"));
        Future<String> submit2 = fixedThreadPool.submit(
                new TestCallableTask(RandomUtil.randomInt(100,400),"t2"));
        Future<String> submit3 = fixedThreadPool.submit(
                new TestCallableTask(RandomUtil.randomInt(30,350),"t3"));
        Future<String> submit4 = fixedThreadPool.submit(
                new TestCallableTask(RandomUtil.randomInt(310,500),"t4"));

        res1 = submit1.get();
        System.out.println(res1);
        res2 = submit2.get();
        System.out.println(res2);
        res3 = submit3.get();
        System.out.println(res3);
        res4 = submit4.get();
        System.out.println(res4);

        fixedThreadPool.shutdown();
    }
}

package cn.demo;


import cn.hutool.core.util.RandomUtil;

import java.time.LocalDateTime;
import java.util.concurrent.Callable;

public class TestCallableTask implements Callable<String> {

    private int testIntVal;
    private String taskSeq;

    public TestCallableTask(int testIntVal, String taskSeq) {
        this.testIntVal = testIntVal;
        this.taskSeq = taskSeq;
    }

    @Override
    public  String call() throws Exception {
        String s = LocalDateTime.now().toString();
        System.out.println(s+"->"+taskSeq+" run ....");

        int i = testIntVal;
        System.out.println(i);

        try {
            Thread.sleep(RandomUtil.randomInt(100,300));
        } catch (InterruptedException e) {
            e.printStackTrace();
        }

        if (i>300){
            return "300more";
        }else {
            return "300less";
        }
    }
}

package cn.demo;

import java.util.concurrent.*;

public class ExecutorTestsForRunnableTask {

    public static void main(String[] args) throws ExecutionException, InterruptedException {

        String res1 = "";
        String res2 = "";
        String res3 = "";
        String res4 = "";
        ExecutorService fixedThreadPool = Executors.newFixedThreadPool(3);

        //submit 提交4个任务, 实际执行时,任务是并发执行的,执行顺序不固定
        Task1Param task1Param = new Task1Param();
        task1Param.setUrl("f23r3r");
        task1Param.setName("1heg43t34t34t");
        Future<String> stringFuture = fixedThreadPool.submit(
            new TestTask1Runnable(task1Param), "success1 ok");

        Task1Param t2 = new Task1Param();
        t2.setUrl("gnsg2323");
        t2.setName("2wwswer2r1asdaaws");
        Future<String> f2 = fixedThreadPool.submit(new TestTask1Runnable(t2), "success2 ok");

        Task1Param t3 = new Task1Param();
        t3.setUrl("thwasr23r");
        t3.setName("3erzawfe23rawsf");
        Future<String> f3 = fixedThreadPool.submit(new TestTask1Runnable(t3), "success3 ok");

        Task1Param t4 = new Task1Param();
        t4.setUrl("mjkdsragt");
        t4.setName("4tbertydraewrsfk");
        Future<String> f4 = fixedThreadPool.submit(new TestTask1Runnable(t4), "success4 ok");


        res1 = stringFuture.get();
        System.out.println(res1);
        res2 = f2.get();
        System.out.println(res2);
        res3 = f3.get();
        System.out.println(res3);
        res4 = f4.get();
        System.out.println(res4);

        fixedThreadPool.shutdown();
    }
}

package cn.demo;

import cn.hutool.core.util.RandomUtil;
import java.time.LocalDateTime;

public class TestTask1Runnable implements Runnable{

    private Task1Param task1Param;

    public TestTask1Runnable(Task1Param task1Param) {
        this.task1Param = task1Param;
    }

    @Override
    public void run() {
        try {
            Thread.sleep(RandomUtil.randomInt(200,600));
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        System.out.println(task1Param.getName());
        System.out.println(task1Param.getUrl());
        String s = LocalDateTime.now().toString();
        System.out.println(s+" TestTask1Runnable run ....");
    }
}

package cn.demo;


import cn.hutool.core.util.RandomUtil;
import java.util.concurrent.*;

public class TpeTest {

    private final static ThreadPoolExecutor pool =
            new ThreadPoolExecutor(
                    1,1,
                    1L, TimeUnit.MINUTES,
                    new ArrayBlockingQueue<Runnable>(1),
                    new ThreadPoolExecutor.CallerRunsPolicy());
    public static void main(String[] args) throws ExecutionException, InterruptedException {
        Future<String> submit1 = pool.submit(
                new TestCallableTask(RandomUtil.randomInt(30,1000),"t1"));
        Future<String> submit2 = pool.submit(
                new TestCallableTask(RandomUtil.randomInt(100,400),"t2"));
        Future<String> submit3 = pool.submit(
                new TestCallableTask(RandomUtil.randomInt(30,350),"t3"));
        Future<String> submit4 = pool.submit(
                new TestCallableTask(RandomUtil.randomInt(310,500),"t4"));
        System.out.println("task1-"+submit1.get());
        System.out.println("task2-"+submit2.get());
        System.out.println("task3-"+submit3.get());
        System.out.println("task4-"+submit4.get());

        pool.shutdown();
    }
}