ThreadPoolExecutor 并发调用

概述

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通常为了提供任务的处理速度,会使用一些并发模型，ThreadPoolExecutor中的invokeAll便是一种。

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代码

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package test.current;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.concurrent.Callable;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.Future;

public class TestCallable {

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

        List>> tasks = new ArrayList<>();
        for (int i = 0; i < 10; i++) {
            Callable> task = new Callable>() {
                @Override
                public List call() throws Exception {
                    return Arrays.asList(1L,2L);
                }
            };

            tasks.add(task);
        }

        List finalResults = new ArrayList<>(10);
        List>> results = ThreadPool.getThreadPool().invokeAll(tasks);
        for(Future> ele : results) {
            List list = ele.get();
            finalResults.addAll(list);
        }

        System.out.println(finalResults);
    }
}

package test.current;

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

public class ThreadPool {
    private static final int CORE_SIZE = 8;

    private static final int MAX_SIZE = 12;

    private static final long KEEP_ALIVE_TIME = 30;

    private static final int QUEUE_SIZE = 50000;

    private static ThreadPoolExecutor threadPool = new ThreadPoolExecutor(CORE_SIZE, MAX_SIZE, KEEP_ALIVE_TIME,
            TimeUnit.SECONDS, new ArrayBlockingQueue(QUEUE_SIZE), new ThreadPoolExecutor.AbortPolicy());

    public static ThreadPoolExecutor getThreadPool() {
        return threadPool;
    }
}

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可以把需要执行的任务创建一个Callable task,利用线程池中的线程并发的执行这些task,从而提高任务的执行效率。