Android文件读写示例-优快云博客

本文展示了一个简单的Android应用程序示例，该程序演示了如何在外部SD卡上进行文件的读取与写入操作。通过使用Java代码实现，具体包括检查SD卡状态、创建文件路径、读取指定文件内容及向文件追加写入字符串。

but_read.setOnClickListener(new OnClickListener() {

   @Override
   public void onClick(View v) {
    // TODO Auto-generated method stub
    if (Environment.getExternalStorageState().equals(
      Environment.MEDIA_MOUNTED)) {
     File path = Environment.getExternalStorageDirectory();
     File file = new File(path, "0321Test.txt");
     try {
      FileInputStream in = new FileInputStream(file);
      InputStreamReader isr = new InputStreamReader(in, "GBK");
      BufferedReader br = new BufferedReader(isr);
      String line;
      while ((line = br.readLine()) != null) {
       System.out.println(line);
      }
      br.close();
     } catch (FileNotFoundException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
     } catch (IOException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
     }
    } else {
     Toast.makeText(MainActivity.this, "未发现SD卡",
       Toast.LENGTH_SHORT).show();
    }

}
});

but_write.setOnClickListener(new OnClickListener() {

   @Override
   public void onClick(View v) {
    // TODO Auto-generated method stub
    File path = Environment.getExternalStorageDirectory();
    File file = new File(path, "0321Test.txt");

    try {
     FileOutputStream out = new FileOutputStream(file, true);
     out.write("hello,world!!".getBytes());
     out.close();
    } catch (FileNotFoundException e) {
     // TODO Auto-generated catch block
     e.printStackTrace();
    } catch (IOException e) {
     // TODO Auto-generated catch block
     e.printStackTrace();
    }
   }
  });