getting images from sdcard and binding to listview in android

import java.io.File;

import android.R.string;
import android.os.Bundle;
import android.os.Environment;
import android.app.Activity;
import android.view.Menu;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.Toast;

public class MyActivity extends Activity {
ListView listview;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//String path=Environment.getDataDirectory()+"/DCIM/Camera";
String path=Environment.getExternalStorageDirectory()+"/DCIM/Camera";
File f=new File(path);
if(f.exists())
{
String[] images=f.list();
ArrayAdapter< String> adptr=new ArrayAdapter(getApplicationContext(), android.R.layout.simple_gallery_item, images);
listview=(ListView)findViewById(R.id.listView1);
 listview.setAdapter(adptr);

}
else
{
System.out.println("particular Path not found ");
}
 }



}