Parse JSON with org.json [duplicate]

Question

I'm trying to parse an output from a server that looks like this:

{
  "GetFolderFilesByZoneResult": [
    {
      "ID": 98748,
      "CreatedBy": "",
      "UpdatedBy": "none",
      "CreatedDate": "\/Date(1308273033620+0100)\/",
      "UpdatedDate": "\/Date(1308303003770+0100)\/",  
      "CommentCount": 0,
      "Key": "",
      "Enabled": true,
      "MimeType": "video",
      "Votes": 2,
      "TotalRating": 0,
      "AllowComments": true,
      "ViewCount": 323,
      "ReleaseDate": "\/Date(1308273000000+0100)\/",
      "ExpireDate": "\/Date(4102444800000+0000)\/",
      "Author": "",
      "Size": 133799936,
      "Tag1": "",
      "Tag2": "",
      "Tag3": "",
      "RecycleBin": false
    },
    {
      "ID": 99107,
      "CreatedBy": "",
      "UpdatedBy": "none",
      "CreatedDate": "\/Date(1308583412520+0100)\/",
      "UpdatedDate": "\/Date(1308583564007+0100)\/",     
      "CommentCount": 0,
      "Key": "",
      "Enabled": true,
      "MimeType": "video",
      "Votes": 0,
      "TotalRating": 0,
      "AllowComments": true,
      "ViewCount": 33,
      "ReleaseDate": "\/Date(1308583380000+0100)\/",
      "ExpireDate": "\/Date(4102444800000+0000)\/",
      "Author": "",
      "Size": 47955968,
      "Tag1": "",
      "Tag2": "",
      "Tag3": "",
      "RecycleBin": false
    }
  ]
}

I'm trying to use Java org.json to parse it, but I don't have any experience with JSON/org.json, so I'm having a little trouble. How can I parse this?

Malloy

After parsing the data from the JSON input, how do you intend to use it in Java code? Are you trying to populate a custom Java data structure, or do you just want to quickly retrieve one or two values from the JSON and move on? – Foot

This short video that demonstrates reading and parsing JSON using the org.json library. – Influenza

Answer 1

1) Assuming you have the JSON libraries on your path (from www.json.org), it's pretty easy.

import org.json.JSONTokener;
...

URI uri = new URI("http://someserver/data.json");
JSONTokener tokener = new JSONTokener(uri.toURL().openStream());
JSONObject root = new JSONObject(tokener);

From there, you can address the various parts of the JSON object. Take a look at the Javadocs for the specifics. https://developer.android.com/reference/org/json/package-summary.html

Loftus

With that I get the following error on the last line: Exception in thread "main" java.lang.RuntimeException: Uncompilable source code - Erroneous ctor sym type: <any> – Malloy

Can you post the code you are having problems with? – Loftus

With the exact code you posted, the only difference is the url used – Malloy

the above code may throw an exception, are you catching or handling exceptions appropriately? – Loftus

Broken link above: json.org/javadoc/index.html?org/json/package-summary.html – Regurgitation

fixed the broken link – Loftus

Answer 2

Here is the most universal solution, which allows to parse any JSON type into appropriate Java type:

Object json = new JSONTokener(response).nextValue();

Then you can determine resulting type and handle it appropriately.

Writeoff

Answer 3

I'd pass it

map<String, Object> 

loaded with

map<String, Object> 

in the object field.

Basically recreating the hierarchy of your java classes inside of a large map.

Example :

return ( Map<"GetFolderFilesByZoneResult", Map<"Result1", (object by id 98748) | "Result2", (object by id 99107) | "Result3", etc.

JSON will return that big map very pretty like, and programmatically it's easier to do then lists.

Holdup

I see, but how can I parse that objects/arrays/values with org.json? Can you provide some code? – Malloy

It does it automagically. Push it an object and it decodes it. For instance in my map example, it decodes the objects variable "String ID = 99107" field into JSON as "ID : 99107". – Holdup

I think the question was exactly the opposite, take a json content and get it's value in java object. – Housekeeper