Runnable + ThreadPoolExecutor 實例

自定義Runnable任務(wù)

import java.util.Date;

/**
 * 這是一個簡單的Runnable類，需要大約5秒鐘來執(zhí)行其任務(wù)。
 * @author shuang.kou
 */
public class MyRunnable implements Runnable {

    private String command;

    public MyRunnable(String s) {
        this.command = s;
    }

    @Override
    public void run() {
        System.out.println(Thread.currentThread().getName() + " Start. Time = " + new Date());
        processCommand();
        System.out.println(Thread.currentThread().getName() + " End. Time = " + new Date());
    }

    private void processCommand() {
        try {
            Thread.sleep(5000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }

    @Override
    public String toString() {
        return this.command;
    }
}

調(diào)用構(gòu)造方法初始化線程池，執(zhí)行任務(wù)

import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;

public class ThreadPoolExecutorDemo {

    private static final int CORE_POOL_SIZE = 5;
    private static final int MAX_POOL_SIZE = 10;
    private static final int QUEUE_CAPACITY = 100;
    private static final Long KEEP_ALIVE_TIME = 1L;
    public static void main(String[] args) {

        //使用阿里巴巴推薦的創(chuàng)建線程池的方式
        //通過ThreadPoolExecutor構(gòu)造函數(shù)自定義參數(shù)創(chuàng)建
        ThreadPoolExecutor executor = new ThreadPoolExecutor(
                CORE_POOL_SIZE,
                MAX_POOL_SIZE,
                KEEP_ALIVE_TIME,
                TimeUnit.SECONDS,
                new ArrayBlockingQueue<>(QUEUE_CAPACITY),
                new ThreadPoolExecutor.CallerRunsPolicy());

        for (int i = 0; i < 10; i++) {
            //創(chuàng)建WorkerThread對象（WorkerThread類實現(xiàn)了Runnable 接口）
            Runnable worker = new MyRunnable("" + i);
            //執(zhí)行Runnable
            executor.execute(worker);
        }
        //終止線程池
        executor.shutdown();
        while (!executor.isTerminated()) {
        }
        System.out.println("Finished all threads");
    }
}

Callable + ThreadPoolExecutor代碼實例

自定義Callable實現(xiàn)

import java.util.concurrent.Callable;

public class MyCallable implements Callable<String> {
    @Override
    public String call() throws Exception {
        Thread.sleep(1000);
        //返回執(zhí)行當前 Callable 的線程名字
        return Thread.currentThread().getName();
    }
}

調(diào)用構(gòu)造方法初始化線程池，執(zhí)行任務(wù)

import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.Callable;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.Future;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;

public class CallableDemo {

    private static final int CORE_POOL_SIZE = 5;
    private static final int MAX_POOL_SIZE = 10;
    private static final int QUEUE_CAPACITY = 100;
    private static final Long KEEP_ALIVE_TIME = 1L;

    public static void main(String[] args) {

        //使用阿里巴巴推薦的創(chuàng)建線程池的方式
        //通過ThreadPoolExecutor構(gòu)造函數(shù)自定義參數(shù)創(chuàng)建
        ThreadPoolExecutor executor = new ThreadPoolExecutor(
                CORE_POOL_SIZE,
                MAX_POOL_SIZE,
                KEEP_ALIVE_TIME,
                TimeUnit.SECONDS,
                new ArrayBlockingQueue<>(QUEUE_CAPACITY),
                new ThreadPoolExecutor.CallerRunsPolicy());

        List<Future<String>> futureList = new ArrayList<>();
        Callable<String> callable = new MyCallable();
        for (int i = 0; i < 10; i++) {
            //提交任務(wù)到線程池
            Future<String> future = executor.submit(callable);
            //將返回值 future 添加到 list，我們可以通過 future 獲得 執(zhí)行 Callable 得到的返回值
            futureList.add(future);
        }
        for (Future<String> fut : futureList) {
            try {
                System.out.println(new Date() + "::" + fut.get());
            } catch (InterruptedException | ExecutionException e) {
                e.printStackTrace();
            }
        }
        //關(guān)閉線程池
        executor.shutdown();
    }
}