java多线程Future和Callable用法

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Java多线程搜索文件的代码示例，主要是使用Callable和Future，生成大量生命周期很短的线程，每个目录产生一个线程，可以使用一个线程池来运行任务，多个线程同时搜索文件，然后自动结束线程

package com.huawei.concurrent.thread;

import java.io.*;
import java.util.*;
import java.util.concurrent.*;

public class FileSearch implements Callable<List<File>>{

private File directory;
private FilenameFilter filter;

public FileSearch(File directory, FilenameFilter filter)
{
  super();
  this.directory = directory;
  this.filter = filter;
}

@Override
public List<File> call() throws Exception {
    List<File> list = new ArrayList<File>();
    File[] files = directory.listFiles();
    ArrayList<Future<List<File>>> results = new ArrayList<Future<List<File>>>();
    for(File file : files)
    {
     if(file.isDirectory())
     {
      System.out.println("1111111111111："+file.getParentFile()+"1111111111111111111111："+file.getPath());
      Callable<List<File>> runnable = new FileSearch(file,filter);
      FutureTask<List<File>> task = new FutureTask<List<File>>(runnable);
      results.add(task);
      Thread t = new Thread(task);
      t.start();
     }
     else if (filter.accept(file.getParentFile(), file.getName()))
     {
      System.out.println("父目录路径："+file.getParentFile()+"包子："+file.getPath());
     list.add(file);
     }
    }
    for (Future<List<File>> result : results) {
      list.addAll(result.get());
   }
    return list;
}

public static void main(String[] args) throws Exception
{
  File dir = new File("d:"+File.separator+"work"+File.separator+"test");
  FileSearch search = new FileSearch(dir,new FilenameFilter()
  {

   @Override
   public boolean accept(File dir, String name) {
    return name.endsWith(".java");
   }
  });
  FutureTask<List<File>> task = new FutureTask<List<File>>(search);
  Thread t = new Thread(task);
  t.start();
  for(File f: task.get())
  {
   System.out.println(f.getPath());
   System.out.println(f.getName());

}
}

}

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