Making JSONObject parcelable

Question

I have an array list of JSON Objects that I'm trying to pass like so.

ArrayList<JSONObject> entryCities = new ArrayList<>();

for(int i = 0; i < entries.length(); i++){

    entryCities.add(entries.getJSONObject(i));

}

Intent intent = new Intent(UnitedStatesActivity.this, StateActivity.class);
intent.putExtra("object", entryCities);
startActivity(intent);

I know this doesn't work and that I need to make my array, or the JSON Object in the array parcelable. I started looking at the documentation and have come up with this class that I am wanting to pass the ArrayList<JSONObject> into, but I'm not sure what I'm supposed to be adding in my writeToParcel() method.

Am I writing out the specific values of the JSON Object I want to pull? i.e. out.object.getString("string") and then passing my parcelable object on to the next activity? I'm just not sure what the content of the method should be in the context of making JSON Objects parcelable.

public class StateParcelable extends JSONObject implements Parcelable {

ArrayList<JSONObject> list;


public StateParcelable(ArrayList<JSONObject> list){
    this. list = list;
}

public void writeToParcel(Parcel out, int flags) {

}

public int describeContents(){
    return 0;
}

public static final Parcelable.Creator<StateParcelable> CREATOR
        = new Parcelable.Creator<StateParcelable>() {
    public StateParcelable createFromParcel(Parcel in) {
        return new StateParcelable(in);
    }

    public StateParcelable[] newArray(int size) {
        return new StateParcelable[size];
    }
};

private StateParcelable(Parcel in) {

}

How about having a singleton where you save your object, and you retrieve it in the second activity? Sounds to me like a faster and simpler solution. — noev, Dec 02 '15 at 17:07
Wouldn't I get the same error that requires me to make the JSONObject parcelable when I pass the object into the next class? — Rafa, Dec 02 '15 at 18:07
No because then you wouldn't use the intent to send data. You would do singleton.setJson(json) and in the other activity you would do singleton.getJson(). In this solution you wouldn't get the error because you wouldn't use the putExtra() method which requires you to use a parceable object. — noev, Dec 02 '15 at 19:52

score 5 · Answer 1 · answered Dec 02 '15 at 19:00

Since you already have (what appears to be) a JSONArray of JSONObjects, why not just convert it to a String, pass that, and rebuild the JSONArray from that?

Intent intent = new Intent(UnitedStatesActivity.this, StateActivity.class);
intent.putExtra("object", entries.toString());
startActivity(intent);

And then in the following Activity:

JSONArray entries = new JSONArray(getIntent().getStringExtra("object"));

Otherwise, yes, you'd have to loop through and serialize the individual items in your ArrayList and then rebuild and add them to the list.

Also, a side note, you can pass the individual JSONObjects the same way: via toString() and new JSONObject(getIntent().getStringExtra("object")), respectively.

This is a quick and dirty way. Parcel is aim for low level communication. Json is human readable which because a waste of memory and processing power on converting it. — Fung, Feb 17 '17 at 01:30
There are trade-offs with every decision you make in software. — Cruceo, Feb 20 '17 at 14:56

Making JSONObject parcelable

1 Answers1