Base class to facilitate JSON-backed entities

JsonBackedObject.java

import org.json.JSONException;
import org.json.JSONObject;

public abstract class JsonBackedObject {
    protected final JSONObject source;

    JsonBackedObject(String json) {
        source = parsedObject(json);
    }

    protected String valueForKey(String key) throws JSONException {
        try {
            return source.getString(key);
        } catch (JSONException e) {
            throw new JSONException("The key \"" + key + "\" was not found in the JSON source");
        }
    }

    @NonNull
    private JSONObject parsedObject(String json) {
        JSONObject parsedObject;

        try {
            parsedObject = new JSONObject(json);
        } catch (JSONException anException) {
            try {
                parsedObject = new JSONObject("{}");
            } catch (JSONException notPossible) {
                throw new AssertionError();
            }
        }

        return parsedObject;
    }
}