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Parsing and retrieving elements in a JSON Java

JSONParser parser = new JSONParser();
try {
Object obj = parser.parse(new FileReader("C:/Users/dan/Documents/rental.txt"));
JSONObject jsonObject = (JSONObject) obj;
for(Iterator iterator = jsonObject.keySet().iterator(); iterator.hasNext();) {
String key = (String) iterator.next();
System.out.println(jsonObject.get(key));
}
} catch (Exception e) {
e.printStackTrace();
}
Following is the JSON String:
{
"Search": {
"VehicleList": [
{
"sipp": "CDMR",
"name": "Ford Focus",
"price": 157.85,
"supplier": "Hertz",
"rating": 8.9
},
{
"sipp": "FVAR",
"name": "Ford Galaxy",
"price": 706.89,
"supplier": "Hertz",
"rating": 8.9
}
]
}
}
}
Hi, I can iterate over the whole JSON object with my code but right now I want to print out the name of a vehicle and the price of the vehicle individually. Any help would be appreciated, I am a beginner when it comes to working with JSON.

Your JSON is structured like this JsonObject -> JsonArray-> [JsonObject]
With that in mind you can access the name and price with this
Object obj = parser.parse(new FileReader("C:/Users/dan/Documents/rental.txt"));
JSONArray jsonArray = (JSONObject) obj.getJsonArray("VehicleList");
for(JSONObject jsonObject : jsonArray){
System.out.println(jsonObject.getString("name") + " " + jsonObject.getDouble("price"))
}
}
Depending on your import library it may deviate from the above but the concept is the same.

You need to iterate over the json. For example.
$.Search.VehicleList[0].price will give you [157.85]
$.Search.VehicleList[1].price will give you [706.89]
http://www.jsonquerytool.com/ will come handy for you :)

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)

How to override the 2nd Object JSON with 1st JSON object

I have a situation where I need to override 2nd JSON object value to 1st.
JSON original :-
{
"products": {
"productsApp15": {
"status": "active",
"attribute_set": "Apparel",
"name": "productsApp16",
"product_type": "product",
"code": "productsApp16"
}
}
}
My 1st object :-
{
"productsApp15": {
"attribute_set": "Apparel",
"status": "active",
"name": "productsApp16",
"product_type": "product",
"code": "productsApp16"
}
}
My 2nd object :-
{
"attribute_set": "Apparel",
"status": "active",
"name": "productsApp16",
"product_type": "product",
"code": "try"
}
If you see the value of key -> code is updated here. I want this change in my real or 1st JSON object so I can pass it to my Payload
My Code:-
FileReader reader = new FileReader(filePath);
JSONParser jsonParser = new JSONParser();
JSONObject jsonObject = (JSONObject) jsonParser.parse(reader);
JSONObject jsonObject1 = (JSONObject) jsonObject.get("products");
JSONObject jsonObject2 = (JSONObject)jsonObject1.get("productsApp15");
String firstName = (String) jsonObject2.get("code").toString();
System.out.println("The first name is: " + firstName);
jsonObject2.remove("code");
jsonObject2.put("code", "try");
JSONObject jsonObject3 = (JSONObject)jsonObject1.get("productsApp15");
String firstName2 = (String) jsonObject2.get("code").toString();
System.out.println("The first name is: " + jsonObject3);
JSONObject combined = new JSONObject();
combined.put("Object1", jsonObject1);
combined.put("Object2", jsonObject3);
String firstName3 = (String) jsonObject2.get("code").toString();
System.out.println("The first name is: " + combined);
My Main objective :- I am reading a file which contain my JSON, As you can see my object is again inside an another object .
I want to update the value and then want to pass it to payload.
But how to get the original JSON structure with updated value?
Is it possible?

By Constructing the Java classes against the structure that is required in JSON, this can be achieved.
Messing up with JSON with JSON readers and parser is risky.
public class Products{
private List<Product> productsList;
}
public class Product{
private Map<String, ProProps> map = new HashMap<>();
class ProProps{
private String code;
private String name;
...
}
}
This gives you to map the objects and values.
Get the value of product that you want by key and replace the required props that you want.
Though the conversion of Java - Json takes place, there can be many extensions that can happen when you develop.
You can use this example to convert and do the manipulations required.

how can I get response value (json) to String via Java

I have the json format like following
{
"items": [
{
"id": 0,
"name": "name1"
},
{
"id": 1,
"name": "name2"
}
]
}
I want to filter name from it , Array name = [name1, name2]
#GET (Web service)
#Produces(MediaType.APPLICATION_JSON)
public Response getItem() {
ClientConfig config = new ClientConfig();
HttpAuthenticationFeature feature = HttpAuthenticationFeature.basic(getUserName(),getUserPassword());
config.register(feature);
Client client = ClientBuilder.newClient(config);
WebTarget service = client.target(getURI() + "/Item");
Response response = service.request().header("Content-Type", "application/json").get();
return response;
}
I have already tried here
http://gotoanswer.com/?q=How+to+Parse+the+this+JSON+Response+in+JAVA
then success.
But how can I do to dynamicaly get json format from Response to string
so that I can input to String jsonString.

When you are parsing your json, the 'items' is an array in your json. So if you try to get the 'items' you will need to type cast it to JSONArray. And iterating on this JSONArray you can get the values of the array using the attributes defined like 'name' and 'id'.
Can you try like this?
JSONObject jsonObject = new JSONObject(jsonString);
JSONArray items = (JSONArray) jsonObject.get("items");
for (int 1 = 0; i < items.length(); i++)
{
System.out.println( items.get(i).get("name");
}
Hope it will help you.

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);