1.分支合并 (大数据量的去使用)

 

package com.kuang.forkjoin;import java.util.concurrent.ExecutionException;
import java.util.concurrent.ForkJoinPool;
import java.util.concurrent.ForkJoinTask;
import java.util.function.LongBinaryOperator;
import java.util.stream.LongStream;/*** 程序员分3000 6000(forkjoin) 9000(Stream 并行流) 等*/
public class Test {public static void main(String[] args) throws ExecutionException, InterruptedException {//        test1();11705ms//        test2();7077mstest3();//207ms}//普通程序员  11705public static void test1(){long start = System.currentTimeMillis();Long sum=0L;for (Long i = 1L; i < 10_0000_0000; i++) {sum+=i;}long end = System.currentTimeMillis();System.out.println("sum="+sum+"时间:"+(end-start));}//会使用ForkJoin的  7077public static void test2() throws ExecutionException, InterruptedException {long start = System.currentTimeMillis();ForkJoinPool forkJoinPool = new ForkJoinPool();ForkJoinTask<Long> task = new ForkJoinDemo(0l, 10_0000_0000l);ForkJoinTask<Long> submit = forkJoinPool.submit(task);//提交任务Long sum = submit.get();//forkJoinPool.execute(task);
//        Long aLong = task.get();//拿到返回值long end = System.currentTimeMillis();System.out.println("sum="+sum+"时间:"+(end-start));}//Steam并行流public static void test3(){long start = System.currentTimeMillis();//range() (]long reduce = LongStream.rangeClosed(1L, 10_0000_0000L).parallel().reduce(0, Long::sum);//1+到1000000000Llong end = System.currentTimeMillis();System.out.println("sum="+reduce+"时间:"+(end-start));}}