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Is there a way to name each JSONObject in an array?

{
"Object1": {
"description": "An object",
"data": "more data"
},
"Object2": {
"description": "An object",
"data": "more data"
}
}
How would I use GSON to iterate over the elements in this JSON Object to easily parse each element one by one?

Yes there is, but PrabhakarP is right, associative arrays in JSON are objects. So in your case,
{
"Object1": {
"description": "An object",
"data": "more data"
}
}
You would have a meta-object containing each array element as a property, which doesn't really make sense. You should parse it differently.
But if you still need, in GSON, then try ,
JsonArray body = gson.fromJson(yourString, JsonArray.class);
JSONObject metaObj = new JSONObject();
for (JsonElement currEle : paymentsArray) {
JSONObject currObj = currEle.getAsJsonObject();
String nameVal = currObj.get("name");
currObj.remove("name");
metaObj.addProperty(nameVal, currObj);
}

I would suggest you to add a property to each object in array and use it

I looked at the man page and found I could loop over the set of members in the object.
JsonObject obj = gson.fromJson(jsonFile, JsonObject.class);
for(Map.Entry<String, JsonElement> element : obj.entrySet()) {
Object obj = gson.fromJson(element.getValue(), Object.class);
// do stuff with the object
}

json array to individual strings

Assignment: I am using json-simple. How can I convert this json data into individual java strings?
(Please forgive me if you think that this is a low-level question - I am new to JSON, so I don't know much about that - I've searched a lot, but I couldn't find any answers)
I can get the data if there is only one object ... like this ...
{
"name": "Abhi",
"age": "21"
}
But, I can't get the data if it is in the array
[{
"name": "Abhi",
"age": "21"
}, {
"name": "shek",
"age": "7"
}]
my program logic for json object
JSONParser parser = new JSONParser();
Object obj = parser.parse(new FileReader("A:/c/dataFile.json"));
JSONObject jObj = (JSONObject) obj;
String gName = (String) jObj.get("name");
String gAge = (String) jObj.get("age");
System.out.println(gName);
System.out.println(gAge);
Can anyone show me how to get the data? maybe a code snippet?
Thanks in advance for your answer!

Because in your second case you are getting JSONArray
you may need to check the instance of obj as
if (jObj instanceof JSONObject)
else if (jObj instanceof JSONArray)

Getting the values from a JSON string in Java using GSON

I hope someone can show me where i'm doing it wrong...
I'm using sendgrid for my email tracking and it is posting a JSON like the following:
[
{
"email": "john.doe#sendgrid.com",
"timestamp": 1337966815,
"event": "click",
"url": "http://sendgrid.com"
"userid": "1123",
"template": "welcome"
}
]
Now i want to get the value of for example for "timestamp" which is 1337966815 . I've tried the following:
StringBuffer jb = new StringBuffer();
String line = null;
try {
BufferedReader reader = req.getReader();
while ((line = reader.readLine()) != null)
jb.append(line);
} catch (Exception e) { /*report an error*/ }
String jsonString = jb.toString();
Gson gson = new Gson();
JsonObject jsonObject = gson.fromJson(jsonString, JsonObject.class);
String timeStam = jsonObject.get(timestamp).toString();
The string of jsonString gives me the following which i think is in the right format:
[ { "email": "john.doe#sendgrid.com", "timestamp": 1337966815, "event": "click", "url": "http://sendgrid.com" "userid": "1123", "template": "welcome" }]
But i'm getting the following error at this line of code - JsonObject jsonObject = gson.fromJson(jsonString, JsonObject.class);
java.lang.IllegalStateException: Expected BEGIN_OBJECT but was STRING at line 1 column 52
What am I doing wrong? Is it the format of jsonString that is confusing the JsonObject?
Any help would be very much appreciated.
Kind regards
Francois

The JSON you show in both examples is invalid. There is a comma missing after "url":"http://sendgrid.com"
Ignoring that, the JSON you show is an array of JSON objects, not an object. This is what the [] denotes (correcting the missing comma):
[
{
"email": "john.doe#sendgrid.com",
"timestamp": 1337966815,
"event": "click",
"url": "http://sendgrid.com",
"userid": "1123",
"template": "welcome"
}
]
If you are not mapping this JSON to a Java POJO, then you would want to use Gson's JsonParser to parse your String to a JsonElement (Note you could even use it to parse directly from the Stream, but this if for how you have your code now).
JsonElement je = new JsonParser().parse(jsonString);
Now you have what's called a "parse tree". This JsonElement is the root. To access it as an array you're going to do:
JsonArray myArray = je.getAsJsonArray();
You only show this array containing one object, but let's say it could have more than one. By iterating through the array you can do:
for (JsonElement e : myArray)
{
// Access the element as a JsonObject
JsonObject jo = e.getAsJsonObject();
// Get the `timestamp` element from the object
// since it's a number, we get it as a JsonPrimitive
JsonPrimitive tsPrimitive = jo.getAsJsonPrimitive("timestamp");
// get the primitive as a Java long
long timestamp = tsPrimitive.getAsLong();
System.out.println("Timestamp: " + timestamp);
}
Realize that Gson primarily is meant for Object Relational Mapping where you want to take that JSON and have it converted to a Java object. This is actually a lot simpler:
public class ResponseObject {
public String email;
public long timestamp;
public String event;
public String url;
public String userid;
public String template;
}
Because you have array of these, you want to use a TypeToken and Type to indicate your JSON is a List of these ResponseObject objects:
Type myListType = new TypeToken<List<ResponseObject>>(){}.getType();
List<ResponseObject> myList = new Gson().fromJson(jsonString, myListType);

Is there any tool to generate a String from a JSON?

My doubt is if there is any tool on-line or not to generate a string from a JSON. For example, I have this JSON:
{
"my_json": [
{
"number": 20,
"name": "androider",
},
{
"id": 3432,
"name": "other_name",
}
]
}
If I want to declare a String in my code with this values, so I have to write many quotation marks to have my JSON in a String acceptable format.
So I want to know if thre is some tool to generate this String?

Some good choices are:
Jackson
Gson
They have built in methods to do just whatever you need to do in an efficient way...

I can't quite tell what you want from your original question, but I assume you are trying to output a Java String that contains some JSON that you have generated.
You should use JSONObject and JSONArray to accomplish this.
To create this JSON:
{
"my_json": [
{
"number": 20,
"name": "androider",
},
{
"id": 3432,
"name": "other_name",
}
]
}
You should use this code:
JSONObject a = new JSONObject();
a.put("number", 20);
a.put("name", "androider");
JSONObject b = new JSONObject();
b.put("id", 3432);
b.put("name", "other_name");
JSONArray array = new JSONArray();
array.put(a);
array.put(b);
JSONObject root = new JSONObject();
root.put("my_json", array);
// convert the root object to a string with 4 spaces of indentation
String json = root.toString(4);

As told by Angel, Jackson and Gson are two cool libs.
Gson is very easy to use while Jackson has better performance.

Try here, Go through the answers mentioned below
How to convert String to JSONObject in Java
in short,
Using org.json library:
JSONObject jsonObj = new JSONObject("{\"phonetype\":\"N95\",\"cat\":\"WP\"}");
Here put your own string.
Edit:
Try here,
http://www.mkyong.com/java/json-simple-example-read-and-write-json/
Create a Json object,
JSONObject jsonobj = new JSONObject();
Put your data using...
josnobj.put()

Parsing JSON data in Java for Android

I hope someone might be able to help me.
I am trying to parse following json file:
{"seminar":[
{"categoryid": "1","cpe": "13","inventory":["Discussion","Value x","Value y"
],"teachers": [
{
"titel": "Dipl.-Ing.",
"company": "XY",
"name": "Test",
"id": "3",
}
],
},...
I am lost with parsing the teachers data in...
...
private static final String TAG_teachers = "teachers";
private static final String TAG_TITLE = "title";
for(int i = 0; i < seminar.length(); i++){
JSONObject c = seminar.getJSONObject(i);
...
teachers = c.getJSONArray(TAG_DOZENTEN);
for(int z = 0; z < teachers.length(); z++){
JSONObject d = teachers.getJSONObject(z);
String title = d.getString(TAG_TITLE);
Log.d("JSONParsingActivity", title);
I get the error System.err(1010): org.json.JSONException: Value null
at teachers of type org.json.JSONObject$1 cannot be converted to
JSONArray.
What did I do wrong? As I understand from the JSON documentation, teachers is an JSON Array and not an Object. Is somebody able to help me?

You have an extra (trailing) comma in teachers (after "3"). Not allowed in JSON. Remove it and see if that helps.

If your JSON is really of the form:
{ ... }, { ... }, { ... }, ...
This is invalid JSON
The root enclosure must either be a single object (in {}) or an array (in []).
If your intent is to send an array of objects, then simply wrap the entire thing with square brackets to make it an array and create a JSONArray object from it.
So it must be like this
[ { ... }, { ... }, { ... }, ... ]
You also need to make sure that you don;t have extra commas, unclosed brackets, etc. Use JSONLint or other similar JSON format checker to save yourself some time in finding syntax problems.