Question

I have a large JSON file that contains A LOT of similar code. It’s similar to this:

...,"techs":{"t1":{"level":24,"able":true},"t2":{"level":23,"able":true},"t3":{"level":20,"able":true},"t4"...,"t5"...

It has since t1 until t510… For this reason, I have to create an activity for each tN, so I have to create 510 activities! 0.0

To get acces to each tN I use the following lines:

       Gson gson = new Gson();
        Planets json = gson.fromJson(str, Planets.class);

        System.out.println(json.techs.t1.level);
        System.out.println(json.techs.t2.level);
                         etc...

So I wanna know if there’s the possibility to change t1 for a variable, so that I only have to change the variable to access t2 in a single activity.

For example: String tech = t456; System.out.println(json.techs.tech.level);

Thank you very much in advance!

Answer 1

It’s all just about your imagination 😉

I will come out from this JSON snippet

"techs":{"t1":{"level":24,"able":true},"t2":{"level":23,"able":true},"t3":{"level":20,"able":true}}

This is easily representable as this structure

HashMap<String, InnerObject>

where InnerObject class is defined like this:

class InnerObject {
    int level;
    boolean able;
}

So everything you need is class, where single field will be called techs and it will be defined like this:

class JSONWrapper {
    // another variables
    HashMap<String, InnerObject> techs;
}

To access fields after, you can use:

String techId = "t546";
InnerObject = JSONWrapperInstance.techs.get(techId);

Whole code:

String str = "... contains JSON string ...";
JSONWrapper JSONWrapperInstance = new Gson().fromJson(str, JSONWrapper.class);

And you can walk through all items in HashMap like this:

Iterator<String> iterator = JSONWrapperInstance.techs.keySet().iterator();
while(iterator.hasNext()){
    InnerObject = JSONWrapperInstance.techs.get(iterator.next());
}