print values from json file

Question

I'm using the following code to get JSON data from file, currently I was able to achieve the JSON but in one string. I want to parse it to array. The json file is like this:

{
    "employee": [
        {
            "name": "joan",
            "lastname": "test",
            "age": 23
        },

I'm using the following code to get the data but I get it in one string and I want to print some of the data

JSONObject jsonObject = (JSONObject) parser
                .parse(new FileReader("C:\\MockData\\Json\\js.txt"));

        JSONParser parser1 = new JSONParser();
        ContainerFactory containerFactory = new ContainerFactory() {
            public List<?> creatArrayContainer() {
                return new LinkedList<Object>();
            }

            public Map<?, ?> createObjectContainer() {
                return new LinkedHashMap<Object, Object>();
            }

        };

        Map<?, ?> json = (Map<?, ?>) parser1.parse(jsonObject.toJSONString(), containerFactory);

        Iterator<?> iter = json.entrySet().iterator();
        System.out.println("==iterate result==");

        while (iter.hasNext()) {
            Map.Entry entry = (Map.Entry) iter.next();

            System.out.println(entry.getKey() + "=>" + entry.getValue());

        }

this is the output

employee=[{age=23, name=joan, lastname=test}, {age=22, name=Alex, lastname=avz}, {age=65, name=Dan, lastname=severn}]

Here the entry.getValue() is retuen one concatenated string of the array, the while is running just one time... but I want to loop on it to take the key value. How should I do that? for example if I want to print name alex witn age 22 how should I do that?

Note: The file can be changed so I don't know the keys (now its name but in can be firstName and any other field for that i need generic solution).

if there is a way to use different parser that can do that Im open.

You've tagged your question `jackson`, but as far as I can tell, [Jackson](http://jackson.codehaus.org/) has no `JSONObject`. Are you sure you're not using a different JSON library? — T.J. Crowder, Mar 05 '13 at 08:12
@ T.J. Crowder - the reason that i tag it since maybe jackson have some solution for this issue... — Bill Mackdmor, Mar 05 '13 at 08:14

score 2 · Accepted Answer · edited Mar 11 '13 at 15:35

The following is the full solution to your question. With this code you can break down the data to each employee and also separate the employee attributes.

 Set<String> keySet = jsonObject.keySet();
                Iterator keySetIterator = keySet.iterator();
                while(keySetIterator.hasNext()){
                    JSONArray array = (JSONArray)jsonObject.get(keySetIterator.next());

                        while(employeeKeySetIterator.hasNext()){
                            String employeeKey = employeeKeySetIterator.next().toString();
                            System.out.println(employeeKey + " : "+ employee.get(employeeKey));
                        }
                    }
                }

score 1 · Answer 2 · answered Mar 05 '13 at 08:21

1

You need to cast the inner json string to a JSONArray

JSONArray array = (JSONArray)jsonObject.get("employee");
Iterator<JSONObject> iterator = array.iterator();
while (iterator.hasNext()) {
    System.out.println(iterator.next().toString());
}

answered Mar 05 '13 at 08:21

spiritwalker

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@spiritwalker- Thanks for your solution ,but assume that i dont know the name/key employee(can be person ,customer etc),how should i do that? – Bill Mackdmor Mar 05 '13 at 08:26
then you need to get jsonobject key set first and traverse all the possible keys.Set keySet = jsonObject.keySet(); Iterator keySetIterator = keySet.iterator(); while(keySetIterator.hasNext()){ JSONArray array = (JSONArray)jsonObject.get(keySetIterator.next()); Iterator iterator = array.iterator(); while (iterator.hasNext()) { System.out.println(iterator.next().toString()); } } – spiritwalker Mar 05 '13 at 08:29
@spiritwalker- thanks for your solution ,do you know whether i can break the iterator.next().toString() for example to print just "name":"joan" ? – Bill Mackdmor Mar 05 '13 at 08:51
I've put the full solution in another answer box, hopefully it is what you need. – spiritwalker Mar 05 '13 at 09:31

print values from json file

2 Answers2