How to escape the quotes in JSON Object?

Question

Below is my method which makes the JSONObject and then print out the JSONString.

I am using Google GSON.

private String generateData(ConcurrentMap<String, Map<Integer, Set<Integer>>> dataTable, int i) {

    JsonObject jsonObject = new JsonObject();

    Set<Integer> ap = dataTable.get("TEST1").get(i);
    Set<Integer> bp = dataTable.get("TEST2").get(i);

    jsonObject.addProperty("description", "test data");
    jsonObject.addProperty("ap", ap.toString());
    jsonObject.addProperty("bp", bp.toString());

    System.out.println(jsonObject.toString());

    return jsonObject.toString();
}

Currently if I print out the jsonObject.toString() then it prints out like this -

{"description":"test data","ap":"[0, 1100, 4, 1096]","bp":"[1101, 3, 6, 1098]"}

But this is not what I need. I want to print out like below which is without double quote on ap and bp values.

{"description":"test data","ap":[0, 1100, 4, 1096],"bp":[1101, 3, 6, 1098]}

I am not sure how do I escape that quotes in the JSONObject?

Solution 1

Your problem is that with

jsonObject.addProperty("ap", ap.toString());

you are adding a property which is the String representation of a Set in Java. It has nothing to do with JSON (even if the format looks the same).

You will have to convert your Set into a JsonElement (a JsonArray really but you won't see that).

Create a Gson object somewhere

Gson gson = new Gson();

and use it to convert your Set elements to JsonElement objects and add them to the JsonObject.

jsonObject.add("ap", gson.toJsonTree(ap));
jsonObject.add("bp", gson.toJsonTree(bp));

Gson has its conventions, it converts a Set into a JsonArray which is a sub type of JsonElement and you can therefore add it with JsonObject#add(String, JsonElement).

Solution 2

Use StringEscapeUtils:

import org.apache.commons.lang3.StringEscapeUtils;

(...)

myString = StringEscapeUtils.escapeJson(myString);

On Android, remember to update your app/build.gradle:

compile 'org.apache.commons:commons-lang3:3.4'

Comments

[Admin]

It doesn't work as well. The method addProperty(String, String) in the type JsonObject is not applicable for the arguments (String, JsonElement)

[Sotirios Delimanolis]

@SSH add not addProperty.

[Sotirios Delimanolis]

@SSH Try not to create a Gson object in the method. It will slow everything down as it's a quite heavy initialization. Either pass it as a method argument or reference it with a static variable somewhere.

[Sotirios Delimanolis]

The quotes were a misunderstanding of what they were adding to the Json object. They wanted a Json array instead of a String which is the toString() result of a Set. See the expected JSON.

[Aram]

Looks like this is the only solution. Only thing we need to change the syntax for android.