浅谈Java多线程处理中Future的妙用（附源码）

import java.util.ArrayList;import java.util.List;import java.util.Random;import java.util.concurrent.Callable;import java.util.concurrent.CompletionService;import java.util.concurrent.ExecutorCompletionService;import java.util.concurrent.ExecutorService;import java.util.concurrent.Executors;import java.util.concurrent.Future;public class CompletionServiceTest {  static int numThread =100;  static ExecutorService executor = Executors.newFixedThreadPool(numThread);  public static void main(String[] args) throws Exception{    //data表示批量任务    int[] data =new int[100];    for(int i=1;i<100000;i++){      int idx =i % 100;      data[idx] =i;      if(i%100==0){        testCompletionService(data);        data =new int[100];      }    }  }  private static void testCompletionService(int [] data) throws Exception{        CompletionService<Object> ecs = new ExecutorCompletionService<Object>(executor);    for(int i=0;i<data.length;i++){      final Integer t=data[i];      ecs.submit(new Callable<Object>() {        public Object call() {          try {            Thread.sleep(new Random().nextInt(1000));          } catch (InterruptedException e) {            e.printStackTrace();          }          return t;        }      });    }    //CompletionService会按处理完后顺序返回结果    List<Object> res =new ArrayList<Object>();    for(int i = 0;i<data.length;i++ ){      Future<Object> f = ecs.take();      res.add(f.get());    }           System.out.println(Thread.currentThread().getName()+":"+res);  }  private static void testBasicFuture(int [] data) throws Exception{       List<Future<Object>> res =new ArrayList<Future<Object>>();    for(int i=0;i<data.length;i++){      final Integer t=data[i];      Future<Object> future=executor.submit(new Callable<Object>() {        public Object call() {          return t;        }      });      res.add(future);    }       for(int i = 0;i<res.size();i++ ){      Future<Object> f = res.get(i);      Object rObject =f.get();      System.out.print(":"+rObject);    }           System.out.println("LN");  }}