通过阻塞队列实现文件关键字检索功能

package com.queue;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.util.Scanner;
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.BlockingQueue;

/**
 * 通过阻塞队列实现文件关键字检索功能
 * 
 * @author benDaoRong
 */
public class BlockQueueTest {
	public static void main(String[] args) {
		String path = "F:/个人资料/书籍/TXT&PDF";
		String keyword = "农夫";
		
		final int FILE_QUEUE_SIZE = 10;// 阻塞队列大小
		final int SEARCH_THREADS = 100;// 关键字搜索线程个数

		BlockingQueue<File> queue = new ArrayBlockingQueue<File>(FILE_QUEUE_SIZE);
		
		// 启动线程遍历文件
		FileEnumerationTask enumeration = new FileEnumerationTask(queue, new File(path));
		new Thread(enumeration).start();
		
		// 启动线程检索关键字
		for (int i = 0; i < SEARCH_THREADS; i++) {
			new Thread(new SearchTask(queue, keyword)).start();
		}
	}
}

class FileEnumerationTask implements Runnable {
	// 哑元文件对象，放在阻塞队列最后，用来标示文件已被遍历完
	public static File DUMMY = new File("");
    
	private BlockingQueue<File> queue;

	private File startingDirectory;

	public FileEnumerationTask(BlockingQueue<File> queue, File startingDirectory) {
		this.queue = queue;
		this.startingDirectory = startingDirectory;
	}

	/**
	 * 遍历指定目录下的所有文件以File对象的格式放入阻塞队列中
	 * 
	 * @param directory
	 * @throws InterruptedException
	 */
	public void enumerate(File directory) throws InterruptedException {
		if (directory == null) {
			return;
		}
		if (directory.isDirectory()) {
			File[] files = directory.listFiles();
			for (File file : files) {
				if (file.isDirectory()) {
					enumerate(file);
				}
				else {
					queue.put(file);
				}
			}
		}
		else {
			queue.put(directory);
		}
	}
	
	public void run() {
		try {
			enumerate(startingDirectory);
			queue.put(DUMMY);
		}
		catch (InterruptedException e) {
			e.printStackTrace();
		}
	}

}

class SearchTask implements Runnable {
	private BlockingQueue<File> queue;

	private String keyword;
	
	public SearchTask(BlockingQueue<File> queue, String keyword) {
		this.queue = queue;
		this.keyword = keyword;
	}
	
	public void run() {
		try {
			while (true) {
				File file = queue.take();
				if (file == FileEnumerationTask.DUMMY) {
					queue.put(file);
					break;
				}
				else {
					search(file);
				}
			}
		}
		catch (Exception e) {
			e.printStackTrace();
		}
		
	}
	
	public void search(File file) throws IOException {
		if (file == null) {
			return;
		}
		Scanner scanner = new Scanner(new FileInputStream(file));
		int lineNumber = 0;
		while (scanner.hasNextLine()) {
			lineNumber++;
			String line = scanner.nextLine();
			if (line.contains(keyword)) {
				System.out.println("文件:" + file.getPath() + " 行数:" + lineNumber + " 行内容:" + line);
			}
		}
		scanner.close();
	}
}