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Run time exception while accessing JSON string from server

I am getting a json string back from the local test server as following.
[0,"000SSSBBBB"]
I am not able to fetch the "000SSSBBBB" using JSON object. My code is as following. At run time at following line exception comes as following :
"value 0 at 0 of type java.lang.Integer can not be converted to jsonobject"
JSONObject obj = jsonArray.getJSONObject(i);
Please help as i am new to json.
Thanks

It is not a JSONObject that's why you are facing with that Exception.
Java doc is sometimes helpful: http://www.json.org/javadoc/org/json/JSONObject.html
JSONObject getJSONObject(int index)
Get the JSONObject associated with an index.
You should use :
java.lang.Object get(int index)
Get the object value associated with an index.
or
java.lang.String getString(int index)
Get the string associated with an index.
Don't forget to provide a length check before to take an element a given position.
You can do it by that following code for example: jsonArray.length() == 1

You can try this!
This [0,'000SSSBBBB'] is one object without a key, the object contains an array!
try {
JSONArray jsonArray = new JSONArray("[0,'000SSSBBBB']");
String obj = (String)jsonArray.get(1);
...
}catch(org.json.JSONException e){}

JSON Object to generic ParseFile Object, issue

I have run in to an issue, while converting my iOS app to android.
The database is structured such that there are "stations", these stations can have multiple images attached, in the parse database, the images are an array of imagePointers.
When i wanted to get the images out in iOS here is what i did:
stations = object in this case
// Get a single image
if ([[object objectForKey:#"imagePointers"] objectAtIndex:0] != [NSNull null]) {
PFFile *imageFile = [[[object objectForKey:#"imagePointers"] objectAtIndex:0] objectForKey:#"image"];
cell.coverImageView.file = imageFile;
[cell.coverImageView loadInBackground];
}
Its pretty simple, i just lift the imagePointers array and get objectAtIndex0, then i cast it to a parse file.
But i can't do this in android, here is what i have atm:
JSONArray imagePointers = thisStation.getJSONArray("imagePointers");
try {
JSONObject indexImage = imagePointers.getJSONObject(0);
} catch ( Exception e ) {
JSONObject indexImage = null;
}
Here i get the object at index 0 as a JSONObject, i cannot use this in a ParseFile Object, since i need to cast it as a generic type ParseFile.
How do i do this? Or is my approach completely incorrect?

Fixed it by avoiding casting to JSON, apparently there is a getList method
// Get parse Image as index image
ParseObject thisStation = stationItems.get(position);
List<ParseObject>imagePointers = thisStation.getList("imagePointers");
ParseFile image = imagePointers.get(0).getParseFile("image");
thumbnail.setParseFile(image);
thumbnail.loadInBackground();

I had the same issue for almost 2 days but finally I solved it by the getList method!
Now all you gotta do is use getList instead of getJSONObject or getJSONArray or whatever, because when you use them you will not be able to use the getParseFile for any of those believe me.
But instead you can do something like:
val obj = parseObject.getList("listname")
val file = obj[0].getParseFile("image")
Now, I don't remember how the syntex is or so but the key here is to use the getList method if you want to get list of all images you saved in a Back4app Parse JSONArray.
Hope you found it helpful.
Goodluck

Processing: how to check if JSON Objects are bound

Since the Processing forum is down I hope one of you guys can help me out.
I made a Processing sketch that pulls data from an API (test here: http://www.europeana.eu/portal/api/console.html ) in JSON-format and reads some fields of this data for visualization. Everything works fine so far except when there are fields that are not bound to every JSONObject.
This is the code for the retrieval of the data:
JSONObject json;
json = loadJSONObject("data.json"); // loading my JSON file into the object
JSONArray CHOData = json.getJSONArray("items"); // array of the items I want data from
for (int i = 0; i < CHOData.size(); i++) {
JSONObject CHO = CHOData.getJSONObject(i); // get a specific item
JSONArray previewObj = CHO.getJSONArray("edmPreview"); // this field is an array, so I need to store it in a JSONArray object first
String[] previewArray = previewObj.getStringArray(); // here I store it in my actual string array
String preview = previewArray[0]; // I only need the first element
}
As you can see, I want the first string of the "edmPreview" array in the object. When I run the sketch, I get an error: "JSONObject["edmPreview"] not found."
This is of course because not every item has such an object. But how can I test if there is an object with this name in an item? I tried with if(CHO.getJSONObject("edmPreview") != null), but same error. Is there a way to look into the JSONObject and check the data values for something called "edmPreview"? There is no such function explained in the Processing reference.
The JSON file essentially looks as follows:
{
"items": [
{
"id": "someID",
"edmPreview": [
"http://europeanastatic.eu/api/image?uri=someimage.jpg"
],
// some other fields
}, // some other items
]
}
I'm new to this JSON-stuff, so maybe I miss something important... Thanks for the help!

So I found the answer myself, but not in the Processing reference, but in the actual reference for the JSONObject class in Java (http://www.json.org/javadoc/org/json/JSONObject.html). I tried some of the methods there and found that hasKey() (which is actually something I came up with myself, combining the method "has()" with the term "key", pure coincidence) as a boolean value works very well:
String preview = "";
if (CHO.hasKey("edmPreview")) {
JSONArray previewObj = CHO.getJSONArray("edmPreview");
String[] previewArray = previewObj.getStringArray();
preview = previewArray[0];
}
So now I learned that Processing is essentially just Java and sometimes not every method is written in the Reference. :-)

How to write multiple records to JSON in file on Java

I need to write multiple json in one file, the problem is that every time that inserts inserted as follows:
{"1":"{\"id\":\"1\"}"**}{**"2":"{\"id\":\"2\"}"**}{**"3":"{\"id\":\"3\"}"}
and I need the chain follows to that can be read for JSON:
{"1":"{\"id\":\"1\"}"**,**"2":"{\"id\":\"2\"}"**,**"3":"{\"id\":\"3\"}"}
my code is:
public void writeMci(String mci, String nombreMci) throws Exception{
FileReadWrite a=new FileReadWrite();
JSONObject vjo = new JSONObject();
vjo.put(nombreMci, mci);
try {
BufferedWriter write=new BufferedWriter(new FileWriter("c:\\JSON.json", true));
write.write(vjo.toString());
write.flush();
write.close();
} catch (IOException e) {
//manejar error
}
System.out.print(vjo);
}

The line you want
{"1":"{\"id\":\"1\"}"**,**"2":"{\"id\":\"2\"}"**,**"3":"{\"id\":\"3\"}"}
isn't legal either, I assume you mean (at least) something like this:
{"1":"{\"id\":\"1\"}","2":"{\"id\":\"2\"}","3":"{\"id\":\"3\"}"}
Note that this is not a JSON array, it's an object with string fields respectively called 1 2 and 3 that happen to contain JSON syntaxed string values. Although not illegal, it's highly questionable you actually want that
Now, could it be that you mean
{"1":{"id":"1"},"2":{"id":"2"},"3":{"id":"3"}}
Still an object but with object fields respectively called 1 2 and 3, where the object has just 1 field called id? Anyways (disclaimer: not an org.json library user myself - see below - so not giving any guarantees wrt the accuracy of the code :) ) :
// Create the outer container
JSONObject outer = new JSONObject();
// Create a container for the first contained object
JSONObject inner1 = new JSONObject();
inner1.put("id",1);
// and add that to outer
outer.put("1",inner1);
// Create a container for the second contained object
JSONObject inner2 = new JSONObject();
inner2.put("id",2);
// and add to outer as well
outer.put("2",inner2);
// Create a container for the third contained object
JSONObject inner3 = new JSONObject();
inner3.put("id",3);
// and add that to outer
outer.put("3",inner3);
// at this point
outer.toString()
// should return the JSON String from my last step.
if you actually want it to be an array, you need to put the objects in a JSONArray, and wrap that array as a named field inside an object. The end result will look more or less like this:
{"data": [{"id":"1"},{"id":"2"},{"id":"3"}]}
Code for the inner objects is the same as above, but there's a new layer (the array) between the inner and outer object:
JSONArray middle = new JSONArray();
...
middle.add(inner1);
...
middle.add(inner2);
...
middle.add(inner3);
...
outer.put("data",middle);
Still not sure if that's what you actually want, but I think it's a first step towards a solution. That being said, I would recommend you to switch to a nicer JSON Java library than the one from json.org you are apparently using. Look here for some feedback on different libraries that are available, for my projects I've been using Jackson since quite some time now and I'm very happy with it, but the SO question I linked to talks about several other, excellent alternatives.

You should write both objects, as below:
write.write(vjo.toString());
write.newLine();
write.write(conb.toString());
write.newline();
write.flush();
write.close();

GWT: Dealing with incoming JSON string

I am working on a GWT app that is receiving a JSON string, and I'm having a hard time getting down to the values of each object. I'm trying to transfer the incoming JSON string into an array of objects.
Here is the JSON (from Firebug response tab), The "d" is a .NET thing (Web Service Being Consumed is C#.
{
"d": [
{
"__type": "Event",
"ID": 30,
"Bin": 1,
"Date": "\/Date(1281544749000)\/",
"Desc": "Blue with white stripes.",
"Category": "1"
},
{
"__type": "Event",
"ID": 16,
"Bin": 3,
"Date": "\/Date(1281636239000)\/",
"Desc": "Yellow with pink stripes",
"Category": "1"
}
]
}
I'm trying to parse the JSON into objects, and then insert them into an array. I'm able to use Window.alert and get the entire "d" object to echo. However, when I try to access the elements of the array, GWT debugger just crashes.
//My GWT array to receive JSON Array
ArrayList<Item> itemInfo = new ArrayList<Item>();
//Getting response JSON into something I can work with.(THIS FAILS)
JSONArray jsonValue = JSONParser.parse(incomingJsonRespone);
//Just trying to verify I'm getting values
for (int i=0; i<jsonValue.size(); i++) {
JSONValue jsonItem = = JsonValue.get(i).getString();
Window.alert(jsonItem);
itemInfo.add(jsonItem);
}
I think I have narrowed down the problem to where the JSONArray instance is being created. Is there something blatantly wrong with how I'm trying to do this, because I'm not getting much help in the way of error messages?

In response to RMorrisey's comment:
Actually, it's more convoluted :/ It would look something like this (code untested, but you should get the general idea):
JSONValue jsonValue;
JSONArray jsonArray;
JSONObject jsonObject;
JSONString jsonString;
jsonValue = JSONParser.parseStrict(incomingJsonRespone);
// parseStrict is available in GWT >=2.1
// But without it, GWT is just internally calling eval()
// which is strongly discouraged for untrusted sources
if ((jsonObject = jsonValue.isObject()) == null) {
Window.alert("Error parsing the JSON");
// Possibilites: error during download,
// someone trying to break the application, etc.
}
jsonValue = jsonObject.get("d"); // Actually, this needs
// a null check too
if ((jsonArray = jsonValue.isArray()) == null) {
Window.alert("Error parsing the JSON");
}
jsonValue = jsonArray.get(0);
if ((jsonObject = jsonValue.isObject()) == null) {
Window.alert("Error parsing the JSON");
}
jsonValue = jsonObject.get("Desc");
if ((jsonString = jsonValue.isString()) == null) {
Window.alert("Error parsing the JSON");
}
Window.alert(jsonString.stringValue()); // Finally!
As you can see, when using JSONParser you have to/should be very cautious - that's the whole point, right? To parse an unsafe JSON (otherwise, like I suggested in the comments, you should go with JavaScript Overlay Types). You get a JSONValue, check if it's really what you think it should be, say, a JSONObject, you get that JSONObject, check if it has the "xyz" key, you get a JSONValue, rinse and repeat. Not the most interesting work, but at least its safer than just calling eval() on the whole JSON :)
Attention: as Jason pointed out, prior to GWT 2.1, JSONParser used eval() internally (it only had a parse() method - GWT 2.0 javadocs vs GWT 2.1). In GWT 2.1, parse() became deprecated and two more methods were introduced - parseLenient() (uses eval() internally) and parseStrict() (the safe approach). If you really have to use JSONParser, then I'd suggest upgrading to GWT 2.1 M2, because otherwise you might as well use JSOs. As an alternative to JSONParser for untrusted sources, you could try integrating json2.js as a JSON parser via JSNI.
PS: cinqoTimo, JSONArray jsonValue = JSONParser.parse(incomingJsonRespone); obviously doesn't work because JSONParser.parse has a return type of JSONValue, not JSONArray - didn't your IDE (Eclipse + Google Plugin?) warn you? Or at least the compiler.

It looks like you don't have an array, but a single root object, whose property called 'd' is an array. I'm not familiar with that specific API, but maybe you can try retrieving a JSONObject or similar instead of an array?