title: Write in file .properties
body: <p>I am doing an application with android 2.2, i created a file config.properties in the assets folder, i am trying modify the properties with the following code:</p>
  
  <pre><code>AssetManager am = this.getResources().getAssets();
  Properties pp = new Properties();
  
  InputStream isConfig = am.open("config.properties",Context.MODE_PRIVATE);           
  pp.load(isConfig);
  
  pp.setProperty("SHOP_URL", "NEW_SHOP_URL");//This key exists
  
  try {
      pp.store(new FileOutputStream("config.properties"), null);
  } catch (FileNotFoundException e) {
      e.printStackTrace();
  }catch (IOException e) {
      e.printStackTrace();
  }
  </code></pre>
  
  <p>When run the application,throw this error:
  java.io.FileNoFoundException: Read-only file system.</p>
  
  <p>I am trying adding permissions to solve this error,but i dont know which add.</p>
  
  <p>Thanks by help</p>