findViewById(R.id.file).setOnClickListener(new Button.OnClickListener() {
  @Override
  public void onClick(View v) {
    try {
    //可寫入的方式創(chuàng)建或打開huangbiao.txt文件
    //該文件的路徑是/data/data/包名/files/huangbiao.txt
      FileOutputStream fos = openFileOutput("huangbiao.txt",Context.MODE_APPEND);
    //將字符串寫入到文件中
      fos.write("huangbiao".getBytes());
    //關(guān)閉數(shù)據(jù)流
      fos.close();
    } catch (FileNotFoundException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
    } catch (IOException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
    }
  }
});

findViewById(R.id.read_file).setOnClickListener(new Button.OnClickListener() {
  @Override
  public void onClick(View v) {
    FileInputStream fis;
    try {
    //打開文件并得到InputStream對象
      fis = openFileInput("huangbiao.txt");
    //available()返回估算需要的空間長度
      byte[] buffer = new byte[fis.available()];
    //把數(shù)據(jù)流的內(nèi)容寫入buffer中
      fis.read(buffer);
      String aaa = new String(buffer);
      System.out.println(aaa);
      fis.close();
    } catch (FileNotFoundException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
    } catch (IOException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
    }
  }
});