Best practice for JSON when result is JUST an array?

[S. Dale Morrey]

I can't seem to locate the proper way to use the JSON parser when the result is a pure array with no top level tagging.

Here is an example.  I have a REST API.
The API defines a method GET /getrecentactivity

The result is a pure javascript array that looks exactly like this...

[
  {
    "account": "user1",
    "category": "broadcast",
    "msgid": "some unique id",
    "time": 1395920488,
    "timereceived": 1395920488,
    "message": "Hey everyone this a broadcast!"
  },
  {
    "account": "user1",
    "category": "direct",
    "destination": "user2",
    "msgid": "some other unique id",
    "time": 1395920492,
    "timereceived": 1395920493,
    "message": "Hello user2!  How is life?"
  }
]

The content type is application/json

To access this RESTful API I'm using a ConnectionRequest with a ResponseListener (extends ActionListener) that looks like this.
 public void actionPerformed(ActionEvent evt) {
        Result result;
        try{
            result = Result.fromContent(new String(request.getResponseData()), Result.JSON);
            Application.setActivityList(result);
        }catch(IllegalArgumentException ex){
            Display.getInstance().callSerially(new Runnable(){

                public void run() {
                    Dialog.show("Error!", "The server returned an invalid result.\nPlease try again later.", "OK", null);
                }
            });
        }
    }

Application.setActivityList(result)  looks like

    public static void setActivityList(Result result) {
        recentActivityList = result.getAsArray("/");
    }

Unfortunately that line "recentActivity = result.getAsArray("/");" throws the following exception

java.lang.StringIndexOutOfBoundsException: String index out of range: 1
    at java.lang.String.charAt(String.java:658)
    at com.codename1.processing.ResultTokenizer.next(ResultTokenizer.java:146)
    at com.codename1.processing.ResultTokenizer.tokenize(ResultTokenizer.java:77)
    at com.codename1.processing.Result._internalGetAsArray(Result.java:861)
    at com.codename1.processing.Result.getAsArray(Result.java:844)
    at com.cannibay.potwallet.Application.setActivityList(Application.java:123)
 
I've checked the Network Monitor and the result is exactly what I pasted above.  I've ran it through a JSON validator and it validates fine.  Furthermore I have a webpage with a javascript element that does a JSON.parse on this same REST call and it gives me an array every time.
 
So at this point I'm pretty well stumped.  It seems that / should be the root of the JSON response but clearly the JSON parse doesn't like it.
Any ideas?

[Shai Almog]

This might be an omission in that API. We usually use the vector directly rather than the processing API.

[S. Dale Morrey]

Ok fine, so what would be the current best way of dealing with this? 
Assume I can't change what's coming out of the webserver since I'm not on that team. 

I want the array, but I'm willing to take any array like object.  Can you give me a code sample (or point me to one) of how you're recommending someone deal with this type of situation?
Thanks!

[Steve Hannah]

In the worst case you can use this cn1lib

https://github.com/shannah/CN1JSON

It uses a completely different API and it does support arrays as the root object.

Steve

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Steve Hannah

Web Lite Solutions Corp.

[Sadart Abukari]

It has been a long time since I used this approach. I use the JSONParser instead. Check out if this code will be friendly for your purpose
// Note the root. With JSON array responses starting with [ the parser automatically fixes "root" as the root element for them
// [{"name":"myname"},{"name":"anothername"}]  becomes {"root":[{"name":"myname"},{"name":"anothername"}]}
// Array = Vector / ArrayList eg {"student":[{"name":"student1", "class":"4"},{"name":"student2", "class":"8"}]}
[{"name":"student1", "class":"4"},{"name":"student2", "class":"8"}] will be changed to {"root":[{"name":"student1", "class":"4"},{"name":"student2", "class":"8"}]}
// Object = Hashtable/ HashMap eg {"name":"student1", "class":"4"}

    private void fetchFixturesAndResultsList() {
        ConnectionRequest connectionRequest;
        connectionRequest = new ConnectionRequest() {
            // New school
            ArrayList arFixturesResults = new ArrayList();// Array will be ArrayList
            // Old school
            Vector vFixturesResults = new Vector();// Array will be Vector
           
            @Override
            protected void readResponse(InputStream input) throws IOException {
                JSONParser json = new JSONParser();
                // New school
                Map<String, Object> map = json.parseJSON(new InputStreamReader(input));
                arFixturesResults = (ArrayList) map.get("root");
                // Old school
                Hashtable h = json.parseJSON(new InputStreamReader(input));
                vFixturesResults = (Vector) h.get("root");
            }

            @Override
            protected void postResponse() {
                // do anything you want with arFixturesResults or vFixturesResults
                // New school
                for (int i = 0; i < arFixturesForRenderer.size(); i++) {
                    HashMap hListItem = (HashMap) arFixturesForRenderer.get(i);
                    String homeTeamScore = (String) hListItem.get("home team score");
                    String homeTeam = (String) hListItem.get("home team");
                }
                // Old school
                for (int i = 0; i < vFixturesForRenderer.size(); i++) {
                    Hashtable hListItem = (Hashtable) arFixturesForRenderer.elementAt(i);
                    String homeTeamScore = (String) hListItem.get("home team score");
                    String homeTeam = (String) hListItem.get("home team");
                }
               
            }

 
        };
        connectionRequest.setUrl(API_URL + "/views/fixtures_and_results");
        connectionRequest.setPost(false);
        connectionRequest.removeAllArguments();
        NetworkManager.getInstance().addToQueueAndWait(connectionRequest);

    }

[Shai Almog]

Sadrat's code is good although I would cast to java.util.List rather than ArrayList so the code can be more generic.

[Sadart Abukari]

@Shai. Thanks for the recommendation.
@S. Dale Morrey
I made a mistake in the line

Hashtable h = json.parseJSON(new InputStreamReader(input));

correction is
Hashtable h = json.parse(new InputStreamReader(input));
in case you want to use it