외국 사이트에 있는 예제파일인데요

여기에서 특정 폴더의 이미지들만 보여주려면 어떻게 해야되나요??

어느 부분을 어떻게 수정해야되는지 알려주세요

sd카드의 DCIM/test

여기 폴더를 지정하려면 어떻게 해야되는지...

package com.isummation.customgallery;

import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.net.Uri;
import android.os.Bundle;
import android.provider.MediaStore;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.Button;
import android.widget.CheckBox;
import android.widget.GridView;
import android.widget.ImageView;
import android.widget.Toast;

public class AndroidCustomGalleryActivity extends Activity {
 private int count;
 private Bitmap[] thumbnails;
 private boolean[] thumbnailsselection;
 private String[] arrPath;
 private ImageAdapter imageAdapter;
 
 /** Called when the activity is first created. */
 @Override
 public void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.main);
  
  final String[] columns = { MediaStore.Images.Media.DATA, MediaStore.Images.Media._ID };
  final String orderBy = MediaStore.Images.Media._ID;
  Cursor imagecursor = managedQuery(
    MediaStore.Images.Media.EXTERNAL_CONTENT_URI, columns, null,
    null, orderBy);
  int image_column_index = imagecursor.getColumnIndex(MediaStore.Images.Media._ID);
  this.count = imagecursor.getCount();
  this.thumbnails = new Bitmap[this.count];
  this.arrPath = new String[this.count];
  this.thumbnailsselection = new boolean[this.count];
  for (int i = 0; i < this.count; i++) {
   imagecursor.moveToPosition(i);
   int id = imagecursor.getInt(image_column_index);
   int dataColumnIndex = imagecursor.getColumnIndex(MediaStore.Images.Media.DATA);
   thumbnails[i] = MediaStore.Images.Thumbnails.getThumbnail(
     getApplicationContext().getContentResolver(), id,
     MediaStore.Images.Thumbnails.MICRO_KIND, null);
   arrPath[i]= imagecursor.getString(dataColumnIndex);
  }
  GridView imagegrid = (GridView) findViewById(R.id.PhoneImageGrid);
  imageAdapter = new ImageAdapter();
  imagegrid.setAdapter(imageAdapter);
  imagecursor.close();
  
  final Button selectBtn = (Button) findViewById(R.id.selectBtn);
  
  //선택된 아이템 수를 보여준다
  selectBtn.setOnClickListener(new OnClickListener() {
   
   public void onClick(View v) {
    // TODO Auto-generated method stub
    final int len = thumbnailsselection.length;
    int cnt = 0;
    String selectImages = "";
    for (int i =0; i<len; i++)
    {
     if (thumbnailsselection[i]){
      cnt++;
      selectImages = selectImages + arrPath[i] + "|";
     }
    }
    if (cnt == 0){
     Toast.makeText(getApplicationContext(),
       "Please select at least one image",
       Toast.LENGTH_LONG).show();
    } else {
     Toast.makeText(getApplicationContext(),
       "You've selected Total " + cnt + " image(s).",
       Toast.LENGTH_LONG).show();
     Log.d("SelectedImages", selectImages);
    }
   }
  });
 }

 public class ImageAdapter extends BaseAdapter {
  private LayoutInflater mInflater;

  public ImageAdapter() {
   mInflater = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
  }

  public int getCount() {
   return count;
  }

  public Object getItem(int position) {
   return position;
  }

  public long getItemId(int position) {
   return position;
  }

  public View getView(int position, View convertView, ViewGroup parent) {
   ViewHolder holder;
   if (convertView == null) {
    holder = new ViewHolder();
    //이미지 뷰 하나
    convertView = mInflater.inflate(
      R.layout.galleryitem, null);
    holder.imageview = (ImageView) convertView.findViewById(R.id.thumbImage);
    holder.checkbox = (CheckBox) convertView.findViewById(R.id.itemCheckBox);
    
    convertView.setTag(holder);
   }
   else {
    holder = (ViewHolder) convertView.getTag();
   }
   holder.checkbox.setId(position);
   holder.imageview.setId(position);
   //체크 박스 선택시
   holder.checkbox.setOnClickListener(new OnClickListener() {
    
    public void onClick(View v) {
     // TODO Auto-generated method stub
     CheckBox cb = (CheckBox) v;
     int id = cb.getId();
     if (thumbnailsselection[id]){
      cb.setChecked(false);
      thumbnailsselection[id] = false;
     } else {
      cb.setChecked(true);
      thumbnailsselection[id] = true;
     }
    }
   });
   holder.imageview.setOnClickListener(new OnClickListener() {
    
    public void onClick(View v) {
     // TODO Auto-generated method stub
     
     CheckBox cb = (CheckBox) v;
     int id = cb.getId();
     if (thumbnailsselection[id]){
      cb.setChecked(false);
      thumbnailsselection[id] = false;
     } else {
      cb.setChecked(true);
      thumbnailsselection[id] = true;
     }
//     int id = v.getId();
//     Intent intent = new Intent();
//     intent.setAction(Intent.ACTION_VIEW);
//     intent.setDataAndType(Uri.parse("file://" + arrPath[id]), "image/*");
//     startActivity(intent);
    }
   });
   holder.imageview.setImageBitmap(thumbnails[position]);
   holder.checkbox.setChecked(thumbnailsselection[position]);
   holder.id = position;
   return convertView;
  }
 }
 class ViewHolder {
  ImageView imageview;
  CheckBox checkbox;
  int id;
 }
}