import java.io.BufferedWriter; 
 import java.io.File; 
 import java.io.FileInputStream; 
 import java.io.FileWriter; 
 import java.io.IOException; 
 import java.util.ArrayList; 
 import java.util.List; 
 import java.util.Scanner; 
 import java.util.concurrent.ArrayBlockingQueue; 
 import java.util.concurrent.BlockingQueue; 
  
 public class BlockingQueueTest { 
 	public static void main(String[] args) { 
 		Scanner in = new Scanner(System.in); 
 		System.out.print("Enter base directory (e.g. f:/test): "); 
 		String directory = in.nextLine(); 
 		System.out.print(" Enter original string (e.g. frame): "); 
 		String keyword = in.nextLine(); 
 		System.out.print("  Enter replace with (e.g. MyFrame): "); 
 		String replace = in.nextLine(); 
 		final int FILE_QUEUE_SIZE = 10; 
 		final int SEARCH_THREADS = 100; 
 		BlockingQueue <File> queue = new ArrayBlockingQueue <File>(FILE_QUEUE_SIZE); 
 		FileEnumerationTask enumerator = new FileEnumerationTask(queue, new File(directory)); 
 		new Thread(enumerator).start(); 
 		for (int i = 1; i  <= SEARCH_THREADS; i++) 
 			new Thread(new SearchTask(queue, keyword, replace)).start(); 
 	} 
 } 
  
 /** 
  * This task enumerates all files in a directory and its subdirectories. 
  */ 
 class FileEnumerationTask implements Runnable { 
 	/** 
 	 * Constructs a FileEnumerationTask. 
 	 *  
 	 * @param queue the blocking queue to which the enumerated files are added 
 	 * @param startingDirectory the directory in which to start the enumeration 
 	 */ 
 	public FileEnumerationTask(BlockingQueue <File> queue, File startingDirectory) { 
 		this.queue = queue; 
 		this.startingDirectory = startingDirectory; 
 	} 
  
 	public void run() { 
 		try { 
 			enumerate(startingDirectory); 
 			queue.put(DUMMY); 
 		} catch (InterruptedException e) { 
 		} 
 	} 
  
 	/** 
 	 * Recursively enumerates all files in a given directory and its 
 	 * subdirectories 
 	 *  
 	 * @param directory the directory in which to start 
 	 */ 
 	public void enumerate(File directory) throws InterruptedException { 
 		File[] files = directory.listFiles(); 
 		for (File file : files) { 
 			if (file.isDirectory()) 
 				enumerate(file); 
 			else 
 				queue.put(file); 
 		} 
 	} 
  
 	public static File DUMMY = new File(""); 
  
 	private BlockingQueue <File> queue; 
 	private File startingDirectory; 
 } 
  
 /** 
  * This task searches files for a given keyword. 
  */ 
 class SearchTask implements Runnable { 
 	/** 
 	 * Constructs a SearchTask. 
 	 *  
 	 * @param queue the queue from which to take files 
 	 * @param keyword the keyword to look for 
 	 */ 
 	public SearchTask(BlockingQueue <File> queue, String keyword, String replace) {