/**
 * Result.java
 * @author Charzous
 * @date 2021/1/20 11:00
 *
 */
 
package SearchFiles;
 
 
public class Result {
 boolean found;
 String path;
 
 
 public void setFound(boolean found){
 this.found=found;
 }
 
 public boolean isFound(){
 return this.found;
 }
 
 public void setPath(String path){
 this.path=path;
 }
 
 public String getPath(){
 return this.path;
 }
}

/**
 * 
 * SerialSearch.java 
 * @author Charzous
 * @date 2021/1/20 11:15
 *
 */
 
package SearchFiles;
 
import java.io.File;
 
public class SerialFileSearch {
 public static void searchFiles(File file,String fileName,Result result){
 File[] contents;
 contents=file.listFiles();
 
 if ((contents==null)||(contents.length==0))
 return;
 
 for (File content:contents){
 if (content.isDirectory())
 searchFiles(content,fileName,result);
 else{
 if (content.getName().equals(fileName)){
  result.setPath(content.getAbsolutePath());
  result.setFound(true);
  System.out.println("Serial Search Path: "+result.getPath());
  return;
 }
 }
 if (result.isFound())
 return;
 }
 }
 
 public static void main(String[] args) {
 Result result=new Result();
 File file=new File("D:\\");
 long startTime=System.currentTimeMillis();
 String fileName="maskOrder.txt";
 SerialFileSearch.searchFiles(file,fileName,result);
 
 if (!result.isFound())
 System.out.println("未找到該文件："+fileName);
 else
 System.out.println("找到該文件："+fileName+"!");
 System.out.println("查詢時(shí)間："+(System.currentTimeMillis()-startTime)+"ms");
 }
}

/**
 * ParallelGroupFileTask.java
 * @author Charzous
 * @date 2021/1/20 11:31
 *
 */
package SearchFiles;
 
 
import java.io.File;
import java.util.concurrent.ConcurrentLinkedQueue;
 
class ParallelGroupFileTask implements Runnable {
 private final String fileName;
 private final ConcurrentLinkedQueue<File> directories;
 private final Result parallelResult;
 private boolean found;
 
 public ParallelGroupFileTask(String fileName, ConcurrentLinkedQueue<File> directories, Result parallelResult) {
 this.fileName = fileName;
 this.directories = directories;
 this.parallelResult = parallelResult;
 }
 
 @Override
 public void run() {
 while (directories.size() > 0) {
 File file = directories.poll();
 try {
 processDirectory(file,fileName,parallelResult);//遞歸
 if (found) {
  System.out.println(Thread.currentThread().getName() + " has found the file");
  System.out.println("parallel search:Path :" + parallelResult.getPath());
  return;
 }
 } catch (Exception e) {
 System.out.println(Thread.currentThread().getName() + " hae been interrupted");
 }
 }
 }
 
 public void processDirectory(File file, String fileName, Result parallelResult) throws InterruptedException {
 File[] contents;
 contents = file.listFiles();
 
 if ((contents == null) || (contents.length == 0))
 return;
 
 for (File content : contents) {
 if (content.isDirectory()) {
 processDirectory(content, fileName, parallelResult);
 if (Thread.currentThread().isInterrupted())
  throw new InterruptedException();
 
 if (found)
  return;
 } else {
 processFile(content, fileName, parallelResult);//遞歸
 if (Thread.currentThread().isInterrupted())
  throw new InterruptedException();
 if (found)
  return;
 }
 }
 }
 
 public void processFile(File content, String fileName, Result parallelResult) {
 if (content.getName().equals(fileName)) {
 parallelResult.setPath(content.getAbsolutePath());
 this.found = true;
 }
 }
 
 public boolean getFound() {
 return found;
 }
 
 
}

/**
 * ParallelGroupFileSearch.java
 * @author Charzous
 * @date 2021/1/20 11:40
 *
 */
package SearchFiles;
 
import java.io.File;
import java.util.concurrent.ConcurrentLinkedQueue;
 
public class ParallelGroupFileSearch {
 public static void searchFiles(File file, String fileName, Result parallelResult) {
 ConcurrentLinkedQueue<File> directories = new ConcurrentLinkedQueue<>();
 File[] contents = file.listFiles();
 
 for (File content : contents) {
 if (content.isDirectory())
 directories.add(content);
 }
 int numThreads = Runtime.getRuntime().availableProcessors();
 Thread[] threads = new Thread[numThreads];
 
 ParallelGroupFileTask[] tasks = new ParallelGroupFileTask[numThreads];
 for (int i = 0; i < numThreads; i++) {
 tasks[i] = new ParallelGroupFileTask(fileName, directories, parallelResult);
 threads[i] = new Thread(tasks[i]);
 threads[i].start();
 }
 
 boolean finish = false;
 
 int numFinished = 0;
 while (!finish) {
 numFinished = 0;
 for (int i = 0; i < threads.length; i++) {
 if (threads[i].getState() == Thread.State.TERMINATED) {
  numFinished++;
  if (tasks[i].getFound())
  finish = true;
 }
 }
 if (numFinished == threads.length)
 finish = true;
 }
 if (numFinished != threads.length) {
 for (Thread thread : threads)
 thread.interrupt();
 }
 
 }
 
 public static void main(String[] args) {
 Result result=new Result();
 File file=new File("D:\\");
 String fileName="maskOrder.txt";
 long startTime=System.currentTimeMillis();
 
 ParallelGroupFileSearch.searchFiles(file,fileName,result);
 
 
 System.out.println("查詢時(shí)間："+(System.currentTimeMillis()-startTime)+"ms");
 }
 
}