小编sha*_*nks的帖子

我正在尝试了解java 8并行流.我写了下面的代码,首先使用Executor,然后使用并行流.看起来平行流需要两倍(10秒)的时间与Executor接近(5秒).在我看来,并行流也应该表现出类似的性能.任何想法为什么并行流需要两倍的时间？我的电脑有8个核心.

/**
 * 
 */
package com.shashank.java8.parallel_stream;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Date;
import java.util.List;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;

/**
 * @author pooja
 *
 */
public class Sample {

    public static int processUrl(String url) {

        try {
            Thread.sleep(5000);
        } catch (InterruptedException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        System.out.println("Running Thread " + Thread.currentThread());
        return url.length();
    }

    /**
     * @param args
     * @throws Exception
     */
    public static void main(String[] args) throws Exception {
        usingExecutor();
        usingParallelStream(); …