Cache Staheli Cache Staheli - 4 months ago 33
JSON Question

In Gson, how do I add a JsonArray to a JsonObject?

Suppose that I am trying to get a Json structure like this:

{
"rows": [
{
"date_str": "2016-07-01",
"sleep_7_or_more_hours": true,
"activity_minutes": "0",
"water_5_or_more_cups": true,
"fruit_veg_4_or_more_servings": true,
"physical_activity_description": "walking"
}
{
"date_str": "2016-07-02",
"sleep_7_or_more_hours": true,
"activity_minutes": "30",
"water_5_or_more_cups": true,
"fruit_veg_4_or_more_servings": true,
"physical_activity_description": "walking"
}
...etc
]
}


Some questions about building this Json:


  1. How can I specify the name of the
    JsonArray
    ? I need it to be named, in the Json,
    "rows"
    .

  2. How can I add the
    JsonArray
    rows
    to a
    JsonObject
    (I assume that's what the outer brackets mean)?



This is the code that I am using to do it:

JsonArray rows = new JsonArray();

//Code to get local dates omitted
for (LocalDate date = start; !date.isAfter(end); date = date.plusDays(1))
{
JsonObject row = new JsonObject();

DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-mm-dd", Locale.ENGLISH);
String dateString = date.format(formatter);
row.addProperty("date_str", dateString);

boolean sleptLongEnough = (sleepLog.getTimeInBed(getDate(date)) > (7 * 60));
row.addProperty("sleep_7_or_more_hours", sleptLongEnough);

int activityMinutes = (activitiesLog.getMinutesVeryActive(getDate(date)) + activitiesLog.getMinutesFairlyActive(getDate(date)));
...
//Omitted extra code
rows.add(row);
}
JsonObject logs = new JsonObject();
//add rows to logs here.


I need to add
rows
to
logs
. However,
JsonObject
only appears to have
.add(JsonElement)
and
.addProperty(String, variousTypes)
, and nothing to add an array. What am I missing?

EDIT: I am not using Gson to serialize objects because the Json is composed of data items from each of several logs (and not even close to all of the information in each log).

Answer

JsonArray is an instance of JsonElement. So the method .add("name", element), where element is a JsonArray, should just work.