package q.test.filescanner; 

import java.io.File; 
import java.util.ArrayList; 
import java.util.LinkedList; 

import q.test.filescanner.exception.ScanFilesException; 

/** 
 * @author 
 */ 
public class FolderFileScanner { 

  private static ArrayList<Object> scanFiles = new ArrayList<Object>(); 

  /**linkedList實現(xiàn)**/ 
  private static LinkedList<File> queueFiles = new LinkedList<File>(); 


  /** 
   * TODO:遞歸掃描指定文件夾下面的指定文件 
   * @return ArrayList<Object> 
   * @author
   * @time 2017年11月3日 
   */ 
  public static ArrayList<Object> **scanFilesWithRecursion**(String folderPath) throws ScanFilesException{ 
    ArrayList<String> dirctorys = new ArrayList<String>(); 
    File directory = new File(folderPath); 
    if(!directory.isDirectory()){ 
      throw new ScanFilesException('"' + folderPath + '"' + " input path is not a Directory , please input the right path of the Directory. ^_^...^_^"); 
    } 
    if(directory.isDirectory()){ 
      File [] filelist = directory.listFiles(); 
      for(int i = 0; i < filelist.length; i ++){ 
        /**如果當前是文件夾，進入遞歸掃描文件夾**/ 
        if(filelist[i].isDirectory()){ 
        //絕對路徑名字符串
          dirctorys.add(filelist[i].getAbsolutePath()); 
          /**遞歸掃描下面的文件夾**/ 
          **scanFilesWithRecursion**(filelist[i].getAbsolutePath()); 
        } 
        /**非文件夾**/ 
        else{ 
          scanFiles.add(filelist[i].getAbsolutePath()); 
        } 
      } 
    } 
    return scanFiles; 
  } 

  /** 
   * 
   * TODO:非遞歸方式掃描指定文件夾下面的所有文件 
   * @return ArrayList<Object> 
   * @param folderPath 需要進行文件掃描的文件夾路徑 
   * @author 
   * @time 2017年11月3日 
   */ 
  public static ArrayList<Object> scanFilesWithNoRecursion(String folderPath) throws ScanFilesException{ 
    File directory = new File(folderPath); 
    if(!directory.isDirectory()){ 
      throw new ScanFilesException('"' + folderPath + '"' + " input path is not a Directory , please input the right path of the Directory. ^_^...^_^"); 
    } 
    else{ 
      //首先將第一層目錄掃描一遍 
      File [] files = directory.listFiles(); 
      //遍歷掃出的文件數(shù)組，如果是文件夾，將其放入到linkedList中稍后處理 
      for(int i = 0; i < files.length; i ++){ 
        if(files[i].isDirectory()){ 
          queueFiles.add(files[i]); 
        }else{ 
          //暫時將文件名放入scanFiles中 
          scanFiles.add(files[i].getAbsolutePath()); 
        } 
      } 

      //如果linkedList非空遍歷linkedList 
      while(!queueFiles.isEmpty()){ 
        //移出linkedList中的第一個 
        File headDirectory = queueFiles.removeFirst(); 
        File [] currentFiles = headDirectory.listFiles(); 
        for(int j = 0; j < currentFiles.length; j ++){ 
          if(currentFiles[j].isDirectory()){ 
            //如果仍然是文件夾，將其放入linkedList中 
            queueFiles.add(currentFiles[j]); 
          }else{ 
            scanFiles.add(currentFiles[j].getAbsolutePath()); 
          } 
        } 
      } 
    } 

    return scanFiles; 
  } 
}