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get json data based on object name

May be it's a simple task for some one.
I've json like below.
{
"address": {
"state": "World",
"address": "infinite space, 000",
"city": "Android city",
"address2": {
"state": "World2",
"address": "infinite space2, 002",
"city": "Android city2",
"address3": {
"state": "World3",
"address": "infinite space3, 003",
"city": "Android city3"
}
}
},
"valid": {
"state": "World",
"address": "infinite space, 000",
"city": "Android city",
"valid2": {
"state": "World2",
"address": "infinite space2, 002",
"city": "Android city2",
"valid3": {
"state": "World3",
"address": "infinite space3, 003",
"city": "Android city3"
}
}
}
}
This is a sample structure. Some times may have many objects inside of one object. I know this is a bad format of JSON but i've to achieve my requirement by using this only :-(.
My requirement is: when we sending the object name like address3 or valid3 to a method as argument. My method have to return key and value of object (Which we passed as argument). Any one know, how to achieve this in Java?

You can parse the JSON and convert the result into a HashMap<String,String>
Here is sample code for this JSON object .
public HashMap<String,String> getKeyValuePairs(JSONObject json,String key){
HashMap<String,String> jsonHashList=new HashMap<String,String>();
JSONObject desiredJSON = json.get(key);
Iterator<?> keys = desiredJSON.keys();
while( keys.hasNext() ) {
String key2 = (String)keys.next();
if ( desiredJSON.get(key2) instanceof JSONObject ) {
String value = desiredJSON.get(key2);
jsonHashList.add(key2,value);
}
}
return jsonHashList;
}
Note : In this case key is assumed to be at level one of passed JSON so if you want to pass any JSON to get it's key values separated pass the Level One JSON.

This is the solution
private void parseJson(JSONObject jsonObject, String objName){
try {
for(int i = 0; i < jsonObject.length(); i++){
if(jsonObject.get(jsonObject.names().getString(i)) instanceof JSONObject){
JSONObject singleObj = new JSONObject(jsonObject.get(jsonObject.names().getString(i)).toString());
Iterator<String> keys= singleObj.keys();
while (keys.hasNext()){
String keyValue = keys.next();
final String valueString = singleObj.getString(keyValue);
if(!isJSONObjectOrString(valueString)){
if(keyValue.contains(objName) || valueString.contains(objName)
|| jsonObject.names().getString(i).contains(objName)){
Log.e("objectName", jsonObject.names().getString(i));
Log.e(keyValue, valueString);
}
}
}
parseJson(singleObj);
}
}
} catch (JSONException e) {
e.printStackTrace();
}
}

JSON to JSON Transform of input sample using any existing java library/tools

Input:
{
"Student": {
"name" :"abc",
"id" : 588,
"class : "12"
}
}
Reqired Output:
{
"Student": {
"key" :"name",
"value":"abc",
"key" :"id",
"value":"588",
"key" :"class",
"value":"12"
}
}

Your output json invalid. Json object can not duplicate key .
You can use the library org.json and do something like this:
JSONObject jsonObject = new JSONObject(inputJson);
JSONObject outputJson = new JSONObject();
JSONArray array = new JSONArray();
for (Object key : jsonObject.keySet()) {
JSONObject item = new JSONObject();
String keyStr = (String)key;
Object keyvalue = jsonObj.get(keyStr);
item.put(keyStr, keyvalue);
array.put(item);
}
outputJson.put("Student", array);
System.out.println(json.toString());
Output :
{
"Student": [
{
"key": "name",
"value": "abc"
},
{
"key": "id",
"value": "588"
},
{
"key": "class",
"value": "12"
}
]
}

Similar to the other answer, the desired output JSON format is not valid.
The closest valid output would be
{
"Student" : [ {
"key" : "name",
"value" : "abc"
}, {
"key" : "id",
"value" : 588
}, {
"key" : "class",
"value" : "12"
} ]
}
This can be generated via Jolt with the following spec
[
{
"operation": "shift",
"spec": {
"Student": {
"name": {
"$": "Student[0].key",
"#": "Student[0].value"
},
"id": {
"$": "Student[1].key",
"#": "Student[1].value"
},
"class": {
"$": "Student[2].key",
"#": "Student[2].value"
}
}
}
}
]

This is easy to solve with JSLT if we assume the output is made valid JSON by making an array of key/value objects like the other respondents do.
The array function converts an object into an array of key/value objects exactly like you ask for, so the transform becomes:
{"Student" : array(.Student)}

creating JsonObject from JSONArray value in JAVA

I have a JsonArray Object like
JsonArray[0]= { "streetName" : "xyz", "wardName" : "12xz"}
JsonArray[1]= { "doorNumber" : "123", "plot" : "90z"}
JsonArray[2]= { "city" : "pqr", "district" : "nmc"}
JsonArray[3]= { "state" : "hisd", "country" : "kasps"}
I want to convert above JsonArray into JsonObject which will be like
{
"addresss":[ {
"streetName": "xyz",
"wardName": "12xz",
"doorNumber": "123",
"plot": "90z",
"city": "pqr",
"district": "nmc",
"state": "hisd",
"country": "kasps"
}]
}
I tried in different ways using Json Objcet put and traversing JSONarray and appending the value to String builder. No use. any one give me some idea. how to do that. Thanks for your help.

Extracting fields from JSON fields from mongodb

I want to extract all these places mentioned in "location" field and does not want the other fields in the below json.but can't be able to extract since it is nested..Can anyone help me?
DBCursor cursorTotal = coll.find(obje);
while (cursorTotal.hasNext()) {
DBObject curNext = cursorTotal.next();
System.out.println("data::"+curNext.get("list.myList.location");
}
My "curNext" gives output as::
{
"_id": {
"$oid": "51ebe983e4b0d529b4df2a0e"
},
"date": {
"$date": "2013-07-21T13:31:11.000Z"
},
"lTitle": "Three held for running CISF job racket",
"list": {
"myList": [
{
"location": "Germany"
},
{
"location": "Geneva"
},
{
"location": "Paris"
}
]
},
"hash": -1535814113,
"category": "news"
}
I want my output as
Germany,Geneva,Paris

I have been in a long wait here for an answer and finally I got what I was searching for...Just noting my answer so someone else can benefit from it
DBCursor cursorTotal = coll.find(obje);
while (cursorTotal.hasNext()) {
DBObject curNext = cursorTotal.next();
String res=curNext.toString();
JsonElement jelement = new JsonParser().parse(res);
JsonObject jobject = jelement.getAsJsonObject();
jobject = jobject.getAsJsonObject("list");
JsonArray jarray = jobject.getAsJsonArray("myList");
jobject = jarray.get(0).getAsJsonObject();
String result = jobject.get("location").getAsString();
System.out.println("all places::"+result);
}

For finding only locations you should used mongo aggregation, below query will fetch all lcoations array
db.collectionName.aggregate({
"$unwind": "$ner.nerList"
},
{
"$group": {
"_id": "$_id",
"location": {
"$push": "$ner.nerList.location"
}
}
},
{
"$project": {
"location": "$location",
"_id": 0
}
})
Unfortunately I don't know how to convert this in Java but, I find below links which helpfull to you for converting above query in java format
Mongo Java aggregation driver

Get sub-array from JSON

I parsing some data from a json file. Here is my JSON File.
[
{
"topic": "Example1",
"contact": [
{
"ref": [
1
],
"corresponding": true,
"name": "XYZ"
},
{
"ref": [
1
],
"name": "ZXY"
},
{
"ref": [
1
],
"name": "ABC"
},
{
"ref": [
1,
2
],
"name":"BCA"
}
] ,
"type": "Presentation"
},
{
"topic": "Example2",
"contact": [
{
"ref": [
1
],
"corresponding": true,
"name": "XYZ"
},
{
"ref": [
1
],
"name": "ZXY"
},
{
"ref": [
1
],
"name": "ABC"
},
{
"ref": [
1,
2
],
"name":"BCA"
}
] ,
"type": "Poster"
}
]
I can fetch and store data one by one. Like this one
JSONArray getContactsArray = new JSONArray(jsonObject.getString("contact"));
for(int a =0 ; a < getContactsArray.length(); a++)
{
JSONObject getJSonObj = (JSONObject)getContactsArray.get(a);
String Name = getJSonObj.getString("name");
}
1)Now, my question is there any way to get all name values for each array with single query.
2) Can I get all those values in an Array ?
Please correct me, if I am doing anything wrong. Thank you.

Iteration cannot be avoided here as org.json and other Json parsers as well provide random access to objects but not to their properties collectively (as a collection). So, you can't query something like "all name properties of all contact objects" unless you probably get a Json parser like Gson to unmarshall it that way.
But, that's too much to just avoid a for loop when you can definitely shorten the parse by making use of the appropriate API methods to avoid unnecessary object casts.
JSONArray contacts = jsonObject.getJSONArray("contact");
String[] contactNames = new String[contacts.length()];
for(int i = 0 ; i < contactNames.length; i++) {
contactNames[i] = contacts.getJSONObject(i).getString("name");
}

Better to use a json parser such as GSon or Jackson to marshall your json to a java object. Then you can write utitlity method in your java class to retrieve all the names in that object.

Try this:
Create JSONObject of your file and try to get array of all names and iterate it to get all values.
public static String[] getNames(JSONObject jo) {
int length = jo.length();
if (length == 0) {
return null;
}
Iterator i = jo.keys();
String[] names = new String[length];
int j = 0;
while (i.hasNext()) {
names[j] = (String) i.next();
j += 1;
}
return names;
}