android 遍历所有文件夹和子目录搜索文件

import java.io.File;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;
public class ShuosouwenjianActivity extends Activity  implements OnClickListener  {

private File file;
private String path;
private String info;
private String key; //关键字
private TextView result; // 显示结果
private EditText et; // 编辑view
private Button search_btn; // button view

@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);

result = (TextView)findViewById(R.id.TextView_Result);
et = (EditText)findViewById(R.id.key);
search_btn = (Button)findViewById(R.id.button_search);
// file = new File(Environment.getExternalStorageDirectory().getPath());
file = new File("/sdcard/");
info = getString(R.string.info);

search_btn.setOnClickListener(this);
}

@Override
public void onClick(View v) {
// TODO Auto-generated method stub
path = "";
result.setText("");
key = et.getText().toString();
BrowserFile(file);
}

public void BrowserFile(File fileold) {
if (key.equals("")) {
Toast.makeText(this, getString(R.string.pleaseInput), Toast.LENGTH_LONG).show();
} else {
search(fileold);
if (result.getText().equals("")) {
Toast.makeText(this, getString(R.string.notFound), Toast.LENGTH_SHORT).show();
}
}
}

private void search(File fileold)
{
try{
File[] files=fileold.listFiles();
if(files.length>0)
{
for(int j=0;j<files.length;j++)
{
if(!files[j].isDirectory())
{
if(files[j].getName().indexOf(key)> -1)
{
path += "\n" + files[j].getPath();
result.setText(info+path);

//shuju.putString(files[j].getName().toString(),files[j].getPath().toString());
}
}
else{
this.search(files[j]);
}
}
}
}
catch(Exception e)
{

}
}
}

<?xml version="1.0" encoding="utf-8"?>
<AbsoluteLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:id="@+id/widget0"
>

<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/button_search"
android:layout_x="253px"
android:layout_y="5px"
android:text="@string/toSearch"
/>
<EditText
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/key"
android:text="821077962.db"

/>
<TextView
android:layout_width="fill_parent"
android:layout_height="370px"
android:id="@+id/TextView_Result"
android:layout_x="0px"
android:layout_y="60px"
/>
</AbsoluteLayout>

<?xml version="1.0" encoding="utf-8"?>
<resources>
<string name="hello">Hello World, Activity07!</string>
<string name="app_name">文件搜索</string>
<string name="toSearch">搜索</string>
<string name="info">系统SDCard目录文件路径：\n</string>
<string name="pleaseInput">请输入关键字!</string>
<string name="notFound">SD卡中没有相关文件!!</string>
<string name="pathError">读取路径出错!!</string>
</resources>