Android 文件操作

Android 文件操作操作时，要赋予相应的权限：

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<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>

 下面是向文件写文本的代码：

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     private final static String PATH = "/sdcard/lin";

private final static String FILENAME = "/test.txt";

 

@Override

protected void onCreate(Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);

    setContentView(R.layout.activity_main);

    writeFile();

}

 

private void writeFile() {

    //判断设备是否存在sdcard

    if (Environment.MEDIA_MOUNTED.equals(Environment.getExternalStorageState())) {

        try {

            Log.d("File Operation", "start!");

            File path = new File(PATH);

            File file = new File(PATH+FILENAME);

            //如果不存在此路径，则创建此路径

            if (!path.exists()) {

                path.mkdir();

            }

            //如果不存在此文件，则创建此文件

            if (!file.exists()) {

                file.createNewFile();

            }

            //将"text message!"信息写入相应的文件

            OutputStreamWriter osw = new OutputStreamWriter(new FileOutputStream(file));

            osw.write("text message!");

            osw.close();

            Log.d("File Operation", "success!");

        } catch (Exception e) {

            Log.d("File Operation", "file create error");

        }

         

    }

     

}