Android 中的文件存儲

package cn.tttt.android_file;

import java.io.BufferedOutputStream;
import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;

import android.app.Activity;
import android.os.Bundle;
import android.util.Log;

public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        String word = readFromFile();
        Log.i("tttt", "word -> " + word);
    }

    public String readFromFile() {
        StringBuffer result = new StringBuffer();
        FileInputStream fis = null;
        InputStreamReader isr = null;
        BufferedReader br = null;

        try {
            fis = openFileInput("helloworld.txt");
            isr = new InputStreamReader(fis);
            br = new BufferedReader(isr);

            int b;
            while((b = br.read()) != -1) {
                result.append((char) b);
            }
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            if(br != null) {
                try {
                    br.close();
                    br = null;
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }

        return result.toString();
    }

    public void writeToFile() {
        FileOutputStream fos = null;
        BufferedOutputStream bos = null;

        String word = "public static void main(String[] args)";

        try {
            fos = openFileOutput("helloworld.txt", MODE_PRIVATE);
            bos = new BufferedOutputStream(fos);
            bos.write(word.getBytes());
            bos.flush();
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            if (bos != null) {
                try {
                    bos.close();
                    bos = null;
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }

}