线程池小例

package com.test.current;

import java.io.File;
import java.io.FileInputStream;
import java.util.ArrayList;
import java.util.Scanner;
import java.util.concurrent.Callable;
import java.util.concurrent.Executor;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import java.util.concurrent.ThreadPoolExecutor;

public class ThreadPoolTest {
	public static void main(String[] args) {
		//指定目录和关键字  
        String directory = "C:\\Program Files\\Java\\jdk1.6.0_29";  
        String keyword = "volatile";  
        
		ExecutorService pool = Executors.newCachedThreadPool();
		MatchCounter counter = new MatchCounter(new File(directory), keyword, pool);
		Future<Integer> result = pool.submit(counter);
		try{
			System.out.println(result.get()+" matching files");
		}catch (Exception e) {
			e.printStackTrace();
		}
		pool.shutdown();
		int largestPoolSize = ((ThreadPoolExecutor)pool).getLargestPoolSize();
		System.out.println("largest pool size="+largestPoolSize);
	}
}
class MatchCounter implements Callable<Integer>{
	private File directory;
	private String keyword;
	private ExecutorService pool;
	private int count;
	
	public MatchCounter(File directory, String keyword, ExecutorService pool) {
		this.directory = directory;
		this.keyword = keyword;
		this.pool = pool;
	}
	public Integer call() throws Exception {
		count =0;
		try{
			File[] files = directory.listFiles();
			ArrayList<Future<Integer>> results = new ArrayList<Future<Integer>>();
			for (File file : files) {
				if(file.isDirectory()){
					MatchCounter counter = new MatchCounter(file, keyword, pool);
					Future<Integer> result = pool.submit(counter);
					results.add(result);
				}else{
					if(search(file)){
						count ++;
					}
				}
				
				for (Future<Integer> result : results) {
					try{
						count += result.get();
					}catch (Exception e) {
						e.printStackTrace();
					}
				}
			}
		}catch (Exception e) {
		}
		return count;
	}
	public boolean search(File file){
		try{
			Scanner in = new Scanner(new FileInputStream(file));
			boolean found = false;
			while(!found && in.hasNextLine()){
				String line = in.nextLine();
				if(line.contains(keyword)){
					found = true;
				}
			}
			in.close();
			return found;
		}catch(Exception e){
			e.printStackTrace();
			return false;
		}
	}