How to access JSON value? - java

Very new to JSON, this is probably very simple but I'm not sure how to access the "coordinates" in this JSON I know how to go from resourceSets to resources but get stuck at "point":
{
"resourceSets":[
{
"estimatedTotal":1,
"resources":[
{
"__type":"Location:http:\/\/schemas.microsoft.com\/search\/local\/ws\/rest\/v1",
"bbox":[
51.3223903,
-0.2634519,
51.3246386,
-0.2598541
],
"name":"name",
"point":{
"type":"Point",
"coordinates":[
51.3235145,
-0.261653
]
}
}
]
}
]
}
My code so far:
JSONParser parser = new JSONParser();
JSONObject jObj = (JSONObject)parser.parse(result);
JSONArray jsonArray = (JSONArray)jObj.get("resourceSets");
for (int i = 0; i < jsonArray.size(); i ++) {
JSONObject jObjResourceSets = (JSONObject)jsonArray.get(i);
JSONArray jsonArray2 = (JSONArray)jObjResourceSets.get("resources");
System.out.println("Coords" + jObjResourceSets.get("point"));
}

Lets analyse what you're doing (and need to be doing), step by step, in order to get the "coordinates".
First of all, JSON is a great language to transfer static data. It works like a dictionary, where you have a key and the respective value. The key should always be a String, but the value can be a String, an int/double or even an array of other JSON objects. That's what you have.
For instance, "estimatedTotal" is an element (JSONObject) from the "resourceSet" array (JSONArray).
JSONArray jsonArray = (JSONArray)jObj.get("resourceSets");
What you're saying here is straight forward: from your overall JSONObject - jObj - you want to extract the array with key "resourceSets".
Now you have direct access to "resourceSets" array elements: "estimatedTotal", "resources", etc. So, by applying the same logic, in order to access "coordinates" we need to access the "resources" array. And by that I mean to create a JSONArray object like we did before.
JSONArray jsonResourcesArray = (JSONArray)jObjResourceSets.get("resources");
I hope it's clear what's the content of jsonResourcesArray here. It's the JSON array of "__type", "bbox", "name", "point", (...). The Coordinates howevere are inside "point" JSON object. How do we access it?
JSONObject jsonPointObject = (JSONObject) jsonResourcesArray.get("point");
And you know by know that "jsonPointObject" has as its values the following JSON objects: "type" and "coordinates". Coordinates is an array of values, so do we have to use JSONArray or JSONObject?
JSONArray jsonCoordinatesArray = (JSONArray) jsonPointObject.get("coordinates");
From which we mean: from the jsonPointObject we want to extract the array that has key "coordinates". Now your array is a JSONArray with values of jsonCoordinatesArray.get(0) and jsonCoordinatesArray.get(0).
Now you have, not only the code to get those values, but the understanding of how JSON works and how Java interacts with it so you can solve any Json problem from now on.

Normally this code works for the given JSON object. However I'll put the tested formatted JSON value below the java code so you can test it as well.
Note that this code will get you all the coordinates of all the elements in your object.
public static void main(String[] args) throws Exception {
String result = getJsonString();
// Getting root object
JSONParser parser = new JSONParser();
JSONObject jObj = (JSONObject)parser.parse(result);
// Getting resourceSets Array
JSONArray jsonArray = (JSONArray)jObj.get("resourceSets");
for (int i = 0; i < jsonArray.size(); i++) {
// Getting the i object of resourceSet
JSONObject jObjResourceSets = (JSONObject) jsonArray.get(i);
// Getting resources list of the current element
JSONArray jsonArray2 = (JSONArray) jObjResourceSets.get("resources");
for (int j = 0; j < jsonArray2.size(); j++) {
// Getting the j resource of the resources array
JSONObject resource = (JSONObject) jsonArray2.get(j);
// Getting the point object of the current resource
JSONObject point = (JSONObject) resource.get("point");
// Getting the coordinates list of the point
JSONArray coordinates = (JSONArray) point.get("coordinates");
for (int k = 0; k < coordinates.size(); k++) {
System.out.println("Coordinates[" + k + "]: " + coordinates.get(k));
}
// Printing an empty line between each object's coordinates
System.out.println();
}
}
}
The tested JSON Object:
{
"resourceSets":[
{
"estimatedTotal":1,
"resources":[
{
"__type":"Location:http:\/\/schemas.microsoft.com\/search\/local\/ws\/rest\/v1",
"bbox":[
51.3223903,
-0.2634519,
51.3246386,
-0.2598541
],
"name":"name",
"point":{
"type":"Point",
"coordinates":[
51.3235145,
-0.261653
]
}
}
]
}
]
}
If it worked please mark it as the answer.
Good luck ^^
B.

You need the following piece of code to get the data.
JSONArray jsonArray2 = (JSONArray)jObjResourceSets.get("resources");
/**
* here we should note that the "resources" is only having one JSON object hence we can take it as below
* from 0th index using ((JSONObject)jsonArray2.get(0)) these piece of code and the next part is to take the point JSONObject
* from the object.
*/
JSONObject temp = (JSONObject)((JSONObject)jsonArray2.get(0)).get("point");
System.out.println("Coords"+temp.get("coordinates")); //this will give you the coordinates array
//now if you want to do further processing, traverse in the jsonArray like below
JSONArray arr= (JSONArray)temp.get("coordinates");
System.out.println("X coordinate:"+arr.get(0));
System.out.println("Y coordinate:"+arr.get(1));
For more information and further details on JSONObject and JSONArray you can go through this linkparsing-jsonarray-and-jsonobject-in-java-using-json-simple-jar
json-simple-example-read-and-write-json

Related

count key value in JSON and extract values

I have following JSONObject (not array, which I don't mind to convert). I am trying to do two things:
get the count of genre entry as "poetry" (count = 2).
get the key value of author name and genre:
authorName = malcolm
genreName = newsarticle
authorName = keats
genreName = poetry
{ "AddressBook" :{
"Details" :{
"authorname" :{
"Author-malcolm":{
"genre" :"poetry"
}
"Author-keats":{
"genre" :"poetry"
}
}
}
}
}
Code which I tried:
public static void main(String[] args) throws Exception, IOException, ParseException {
JSONParser parser = new JSONParser();
Object obj = parser.parse(new FileReader("My path to JSON"));
JSONObject jsonObject = (JSONObject) obj;
JSONArray arrayhere = new JSONArray();
arrayhere.add(obj);
System.out.println(arrayhere);
int count = 0;
for(int i = 0; i < arrayhere.size(); i++) {
JSONObject element = arrayhere.getJSONObject(i);//The method getJSONObject(int) is undefined for the type JSONArray
String branchName = element.getString("genre");//The method getString(String) is undefined for the type JSONObject
if(branchName.equals("poetry")) {
count ++;
}
}
System.out.println("Count f0r poetry genre=" + count);
}
}
I have looked at solutions all over. There is no question similar to this at stackoverflow. I am not sure if the procedure is correct.
A few problems here.
First, I'm not sure where you got that example JSON but you can't work with that. That's not even valid JSON Formatting.
Looks like you want something like this:
{
AddressBook:
[
{
authorname: "author-malcom",
genre:"poetry"
},
{
authorname: "author-keats",
genre: "poetry"
}
]
}
That's the structure you're trying to create in JSON.
So, you're parsing this in from a file into a JSONObject that has a key called AddressBook inside of it. That key points to an array of JSONObjects representing authors. Each of those objects will have a key called genre. You're trying to access the genre key and count on a condition.
What you did above was create attempt to create a JSONObject from an invalid string, and then add the entire JSONObject itself into the JSONArray. JSONArray.add() doesn't convert an object to an array, it literally adds it onto the array.
jsonObj => {"Name":"name1","Id":1000}
jsonArray.add(jsonObj)
jsonArray => [{"Name":"name1","Id":1000}]
That's what you did in your code above. You didn't create an array from a JSONObject, you added an object to the array.
Proper use is going to look like:
Object obj = parser.parse(new FileReader("path_to_file"));
JSONObject jobj = (JSONObject) obj;
//access key AddressBook
JSONArray author_array = jobj.getJSONArray("AddressBook");
int poetry = 0;
for(int i = 0; i < author_array.length(); i++) {
JSONObject author = (JSONObject) author_array.get(i);
if(author.getString("genre").equals("poetry")) {
poetry++;
}
}
To summarize, you're problems come from a lack of understanding about JSON Formatting and how to access elements within a JSON Object.
Paste in the sample JSONObject I gave you above here. That site will let you visualize what you're working with.

How to put an value to the extracting JSON and display it

I wanna display a parsed json with my values . I mean , I wanna add some values to the json and display it . I can display all result from respond , but I wanna display just the json with my values not all data :)
here i have parsed allready my json
JSONObject jsonObject = new JSONObject(adresUrl);
JSONArray offerResources = jsonObject.getJSONArray("offerResources");
for(int y = 0; y < offerResources.length(); y++){
JSONObject currentTransfer = offerResources.getJSONObject(y);
JSONArray meetPoint = currentTransfer.getJSONArray("meetPoints");
for (int i = 0; i < meetPoint.length(); i++){
JSONObject currentMeetPoints = meetPoint.getJSONObject(i);
String startAddress = currentMeetPoints.getString("startAddress"); // here i wanna put some values , but i dont know how
// here is a litle piece of my json :)
"meetPoints": [
{
"startAddress": "....", // after the collon i have to put my value .
"startLocation": {
thank you for your help
I'm not sure if I understood your question fully but from what I got here is some solution. I simply created a string and couple of Json objects and jsonarray for adding the list of values and put it inside the main json object "jsonValueObject " and accumulate it inside meetPoints.
Accumulate(String key,Object Value) is a key value pair, meaning if key is created then Object is checked for being an array,and if this array has "values", it will be added else new array will be created. "Put" will replace the value if the key exists.
String jsonString = "{\"results\":[{\"Country\":\"value\",\"state\":\"value\" },
{ \"Country\":\"value\", \"state\":\"value\"}]}";
JSONObject meetPoints = new JSONObject(jsonDataString);
JSONObject jsonValueObject = new JSONObject();
JSONArray list = new JSONArray();
jsonValueObject.put("Country", "newValue");
jsonValueObject.put("state", "newValue");
jsonValueObject.put("city", "Chennai");
jsonValueObject.put("street", "Bharathiyar Street");
jsonValueObject.put("date", "14May2017");
jsonValueObject.put("time", "10:00AM");
list.put(jsonValueObject);
meetPoints.accumulate("values", list);
System.out.println(meetPoints);

[Java]: Unable to parse a JSON with no array / sub array in it

I am using the json-simple-1.1.jar
and trying to get multiple (atleast 3) values from the json as shown in the code section.
My code works for a JSON with multiple arrays but not working for simple json format.
{
"Addresses": {
"UserName": "Rahul",
"Status": "Active",
"CreateDate": "2017-01-09T11:39:31.244Z",
"SecretAccessKey": "ABCD-EFGH-HIJK",
"AccessKeyId": "1234567"
}
}
Following is the java logic I am trying to use:
public static String[] getValuesFromJson(String filename, Object key, int exp_sizeOfArray, String[] exp_keys) throws FileNotFoundException, IOException, ParseException {
String valuesFromJson[] = new String[exp_keys.length];
/** Create a JSONParser object*/
JSONParser parser = new JSONParser();
/** Read the JSON file using parser*/
JSONObject jsonObject = (JSONObject) parser.parse(new FileReader(
filename));
System.out.println("JsonObject size: "+jsonObject.keySet().size());
for (Object object : jsonObject.keySet()) {
System.out.println(jsonObject.get(object.toString()));
}
/** Get the values in JSONArray using the key*/
JSONArray jsonArray = (JSONArray) jsonObject.get(key);
for (int i = 0; i < jsonArray.size(); i++) {
/** Add the individual set from JSONArray to a JSONObject */
JSONObject subJsonObject = (JSONObject) parser.parse(jsonArray.get(i).toString());
/** Check for expected size of array */
if(subJsonObject.size() <= exp_sizeOfArray){
int index=0;
/** Check for each key value in the sub-JSONObject keySet*/
for (Object object : subJsonObject.keySet()) {
/** Iterate until the expected key value matches with the actual value*/
for (int j = 0; j < exp_keys.length; j++) {
/** Check if the expected key matches with any of the key value*/
if(object.toString().trim().equals(exp_keys[j].toString().trim())){
System.out.println("Key: '".concat(object.toString()).concat("'\tValue: '").concat(subJsonObject.get(object)+"'"));
valuesFromJson[index] = subJsonObject.get(exp_keys[j]).toString();
index++;
break;
}
}
}
}
}
/** Return the value of expected key*/
return valuesFromJson;
}
I am getting error: "org.json.simple.JSONObject cannot be cast to org.json.simple.JSONArray" on below line:
JSONArray jsonArray = (JSONArray) jsonObject.get(key);
You are trying to cast JSONObject to JSONArray, but there is no array. Rather get all object keys and iterate over it.
If you go to json.org(1) you can find there:
An array is an ordered collection of values. An array begins with [ (left bracket) and ends with ] (right bracket). Values are separated by , (comma)
Voila!
Done it without converting JSONObject to JSONArray
JSONObject jsonObject = (JSONObject) parser.parse(new FileReader(
filename));
/** Creating another JSONObject here */
JSONObject jsonObject2 = (JSONObject) parser.parse(jsonObject.get(key).toString());
for (Object newKey : jsonObject2.keySet()) {
System.out.println("Key: '".concat(newKey.toString()).concat("'\tValue: '").concat(jsonObject2.get(newKey)+"'"));
}
Thank you guys for the help!

simpleJson parsing in Java

I'm very new to parsing JSON. I have looked all over and cannot seem to grasp the idea to my particular problem. I'm having a hard time understanding how to get a JSON object from a JSON array. My example is below
[{"styleId":94,
"status":"verified",
"abv":"4.2",
"name":"Bud Light"}]
Here is my current code
JSONParser parser = new JSONParser();
Object obj = parser.parse(inputLine);
JSONObject jsonObject = (JSONObject) obj;
Long currPage = (Long)jsonObject.get("currentPage");
System.out.println(currPage);
JSONArray jArray = (JSONArray)jsonObject.get("data");
System.out.println(jArray);
inputLine is my orignal JSON. I have pulled a JSONArray out of the original JSONObject that has the "data" tag. Now this is where I'm stuck and given the JSONArray at the top. Not sure how to iterate through the Array to grab JUST the "name" tag.
Thanks for the help in advanced!
To iterate in a JSONArray you need to go through each element in a loop.
int resultSize = jArray.length();
JSONObject result;
for (int i = 0; i < resultSize; i++) {
result = resultsArray.getJSONObject(i);
String name = result.getString("name");
// do whatever you want to do now...
}
just use Gson . it works well out of the box with any object type you supply.
This is an example from the user's guide:
int[] ints2 = gson.fromJson("[1,2,3,4,5]", int[].class);

Android parse Json array of Strings

How can I parse in Android a Json array of strings and save it in a java string array ( like: xy[ ] ) ?
My Json to be parsed :
[
{
"streets": [ "street1", "street2", "street3",... ],
}
]
Later in my code I want to populated with that array a spinner item in my layout.
Everything i tried enden with only one street item listed in the spinner.
To parse
try {
JSONArray jr = new JSONArray("Your json string");
JSONObject jb = (JSONObject)jr.getJSONObject(0);
JSONArray st = jb.getJSONArray("streets");
for(int i=0;i<st.length();i++)
{
String street = st.getString(i);
Log.i("..........",""+street);
// loop and add it to array or arraylist
}
}catch(Exception e)
{
e.printStackTrace();
}
Once you parse and add it to array. Use the same to populate your spinner.
[ represents json array node
{ represents json object node
Try this..
JSONArray arr = new JSONArray(json string);
for(int i = 0; i < arr.length(); i++){
JSONObject c = arr.getJSONObject(i);
JSONArray ar_in = c.getJSONArray("streets");
for(int j = 0; j < ar_in.length(); j++){
Log.v("result--", ar_in.getString(j));
}
}
We need to make JSON object first. For example,
JSONObject jsonObject = new JSONObject(resp);
// resp is your JSON string
JSONArray arr = jsonObject.getJSONArray("results");
Log.i(LOG, "arr length = " + arr.length());
for(int i=0;i<arr.length();i++)
{...
arr may contains other JSON Objects or JSON array. How to convert the JSON depends on the String. There is a complete example with some explanation about JSON String to JSON array can be found at http://www.hemelix.com/JSONHandling

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