Create JSONObject from string

Question

I know that this question was already asked, i tried all solutions but nothing works for me. So i have this json syntax string:

{
   tasks: [
      {
         blockId: "startpoint1",
         properties: [ "aaaa"  ]
      },
      {
         blockId: "endpoint2",
         properties: [ "tttttt" ]
      } 
   ]
}

I tried to create a JSONObject from this String by this way:

JSONParser parser=new JSONParser();
try {
    JSONObject json=(JSONObject) parser.parse(req.getParameter(WORKFLOW_DEFINITION_PROPERTIES));
    } catch (ParseException e1) {
        // TODO Auto-generated catch block
        e1.printStackTrace();
    }

Now i want to loop on the tasks array to get every element blockId. I tried to do this by casting the JSONObject to JSONArray like this:

JSONArray tasks=(JSONArray) json.get("tasks");

but i still enable to loop over tasks to get the blockId's. Can you tell me what i made wrong or how to fix this?

var obj = JSON.parse(string);

Rajesh Murugan
– Rajesh Murugan

2017-08-22 12:54:20 +00:00
Commented Aug 22, 2017 at 12:54 — Rajesh Murugan
– Rajesh Murugan, Commented Aug 22, 2017 at 12:54
I'm in Java no javaScript

nmalloul
– nmalloul

2017-08-22 12:55:24 +00:00
Commented Aug 22, 2017 at 12:55 — nmalloul
– nmalloul, Commented Aug 22, 2017 at 12:55

Anas EL KORCHI · Accepted Answer · 2017-08-22 12:56:35Z

4

You have to use getJsonArray method instead of get method to retrieve the array of tasks :

JSONArray tasks= json.getJsonArray("tasks");

answered Aug 22, 2017 at 12:56

Anas EL KORCHI

2,06818 silver badges26 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

nmalloul Over a year ago

This method is not included in org.json.simple.JSONArray class i use

cralfaro · Accepted Answer · 2017-08-22 12:58:51Z

1

Just change the way you create your JSONObject.

JSONObject jObject = new JSONObject(jsonStr);
//later you can access to your array 
JSONArray tasks=(JSONArray) jObject.get("tasks");

answered Aug 22, 2017 at 12:58

cralfaro

5,9463 gold badges23 silver badges33 bronze badges

2 Comments

nmalloul Over a year ago

The constructor of JSONObject is JSONObject(map), so i can't create a JSONObject directly with a String

cralfaro Over a year ago

Thats not true, with the version <dependency> <groupId>org.json</groupId> <artifactId>json</artifactId> <version>20160810</version> </dependency> you can create an object from a string.

Chandrakant Thakkar · Accepted Answer · 2017-08-22 13:10:21Z

-1

Do you need this?

    var arrayVariable=[
      {
         blockId: "startpoint1",
         properties: [ "aaaa"  ]
      },
      {
         blockId: "endpoint2",
         properties: [ "tttttt" ]
      } 
   ]

    arrayVariable.map(function(d){
       return d.blockId
       });

Out put you will get all you blockId as

     ["startpoint1", "endpoint2"]

answered Aug 22, 2017 at 13:10

Chandrakant Thakkar

9789 silver badges23 bronze badges

2 Comments

nmalloul Over a year ago

No, my json string is created dynamically from an UI diagram so, i can't create it statically like you done

Chandrakant Thakkar Over a year ago

So,Convert you JSON string to JSON Object using JSON.parse(JSONstring) and then use my above method it will work

Collectives™ on Stack Overflow

Create JSONObject from string

3 Answers 3

1 Comment

2 Comments

2 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

1 Comment

2 Comments

2 Comments

Your Answer

Sign up or log in

Post as a guest

Related