Gson Array of Strings to JsonArray

Question

I'm using Gson and am trying to add a bunch of string values into a JsonArray like this:

JsonArray jArray = new JsonArray();
jArray.add("value1");

The problem is that the add method only takes a JsonElement.

I've tried to cast a String into a JsonElement but that didn't work.

How do I do it using Gson?

score 72 · Accepted Answer · edited Nov 20 '18 at 02:06

72

You can create a primitive that will contain the String value and add it to the array:

JsonArray jArray = new JsonArray();
JsonPrimitive element = new JsonPrimitive("value1");
jArray.add(element);

edited Nov 20 '18 at 02:06

Grant Foster

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answered May 08 '12 at 11:56

alexey28

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11

Why is this so **ludicrously** counterintuitive? – allidoiswin Nov 02 '15 at 23:47
And why do the docs tell us there is a JsonArray.add(String)?!? – Casey Murray Jul 29 '16 at 05:47

score 4 · Answer 2 · answered May 08 '12 at 11:51

4

Seems like you should make a new JsonPrimitive("value1") and add that. See The javadoc

answered May 08 '12 at 11:51

slipset

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score 4 · Answer 3 · edited Feb 12 '19 at 16:18

4

For newer versions of Gson library , now we can add Strings too. It has also extended support for adding Boolean, Character, Number etc. (see more here)

Using this works for me now:

JsonArray msisdnsArray = new JsonArray();
for (String msisdn : msisdns) {
    msisdnsArray.add(msisdn);
}

edited Feb 12 '19 at 16:18

Neuron

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answered Jan 11 '17 at 09:52

Nilu

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score 2 · Answer 4 · answered Nov 02 '16 at 16:36

I was hoping for something like this myself:

JsonObject jo = new JsonObject();
jo.addProperty("strings", new String[] { "value1", "value2" });

But unfortunately that isn't supported by GSON so I created this helper:

public static void Add(JsonObject jo, String property, String[] values) {
    JsonArray array = new JsonArray();
    for (String value : values) {
        array.add(new JsonPrimitive(value));
    }
    jo.add(property, array);
}

And then use it like so:

JsonObject jo = new JsonObject();
Add(jo, "strings", new String[] { "value1", "value2" });

Voila!

Gson Array of Strings to JsonArray

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