Android File数据存储

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >
    <EditText 
        android:id="@+id/write_edit"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:lines="4"
        android:gravity="top"
        />
    <Button 
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Save"
        android:onClick="writeFile"
        />
    <EditText 
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:lines="4"
        android:id="@+id/read_edit"
        android:gravity="top"
        android:editable="false"
        android:focusable="false"
        />
    <Button 
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Read"
        android:onClick="readFile"
        />
</LinearLayout>

package com.turboradio.activity;

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;

public class FileSaveActivity extends Activity{
    // 文件名称
    private static final String FILE_NAME = "temp.txt";
    private EditText writeEdit;
    private EditText readEdit;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.file_save);
        writeEdit = (EditText)findViewById(R.id.write_edit);
        readEdit = (EditText)findViewById(R.id.read_edit);
    }
    /**
     * 写文件
*/
    public void writeFile(View v){
        write(writeEdit.getText().toString());
    }
    /**
     * 读文件
*/
    public  void readFile(View v){
        readEdit.setText(read());
    }
    private String read(){
        try {
            FileInputStream fis = openFileInput(FILE_NAME);
            byte [] bytes = new byte [1024];
            fis.read(bytes);
            return new String(bytes);
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return null;
    }
    private void write(String content){
        try {
            FileOutputStream fos = openFileOutput(FILE_NAME,MODE_APPEND);
            fos.write(content.getBytes());
            fos.close();
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}