How to store different types of JSON objects in a list?

Question

I want to display different type of stories in a news feed using a RecyclerView . For example one story could have a template of how the weather changed. So the JSON data would contain the day, temperature etc.

I download the stories as JSON from the database and parse them. Currently, I'm storing the parsed JSON objects in a List<FeedStoryContainer> . FeedStoryContainer has two properties, an int representing the type and an Object containing the data. When it comes time to bind the data I cast the Object into the correct story type which in based on the int type. Is this approach okay?

Answer 1

In my opinion it would be better that your story types should have the same base and api. Keep them in List< StoryBase > with the same api. Casting of object depending of it type ( int ) is some solution but sooner or later it won't help. Better is to use polymorphism.

class Story
{
    void apply( Viewer viewer )
    {
      System.out.println( "Default implementation" )
    }
}

class News extends Story
{
  void apply( Viewer viewer )
  {
     viewer.setTextBody( this.title + " " + this.content );
  }
}

class Wheather extends Story
{
  void apply( Viewer viewer )
  {
     viewer.setTextBody( this.title + " " + this.temperature );
  }
}

code 

List< Story > list;

for( Story story : list )
{
  story.apply( this );
}