Code to list File/Directory in Android

package com.AndroidListFiles;

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

import android.app.ListActivity;
import android.os.Bundle;
import android.os.Environment;
import android.widget.ArrayAdapter;

public class AndroidListFilesActivity extends ListActivity {

private List<String> fileList = new ArrayList<String>();

@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);

File root = new File(Environment
.getExternalStorageDirectory()
.getAbsolutePath());
ListDir(root);

}

void ListDir(File f){
File[] files = f.listFiles();
fileList.clear();
for (File file : files){
fileList.add(file.getPath());
}

ArrayAdapter<String> directoryList
= new ArrayAdapter<String>(this,
android.R.layout.simple_list_item_1, fileList);
setListAdapter(directoryList);
}

}