I've a JSON Array:
JSON_STRING = [{"name": "adminparking1", "id": 1},{"name": "adminparking2", "id": 2}]
And I Want to parse it to a JSON-simple Array and work with json Objects that it provides from it examples I do it this way:
JSONParser jsonParser = new JSONParser();
Object res_obj = jsonParser.parse(JSON_STRING);
JSONArray json = (JSONArray) res_obj; //(HERE Error Occurs)
It gives me this error:
java.lang.ClassCastException: java.lang.String cannot be cast to org.json.simple.JSONArray
how can i get rid of this error?
This code works just fine, if JSON string is valid
public static void main() throws ParseException {
String JSON_STRING = "[{\"name\": \"adminparking1\", \"id\": 1},{\"name\": \"adminparking2\", \"id\": 2}]";
JSONParser jsonParser = new JSONParser();
Object res_obj = jsonParser.parse(JSON_STRING);
JSONArray json = (JSONArray) res_obj; // no Error
System.out.println(json.get(1));
}
prints
{"name":"adminparking2","id":2}
Have you tried this:
JSONArray arr = new JSONArray(JSON_STRING);
//loop through each object
for (int i=0; i<arr.length(); i++){
JSONObject jsonProductObject = arr.getJSONObject(i);
String name = jsonProductObject.getString("name");
String url = jsonProductObject.getString("id");
}
Related
So the json look like this
{
"cover":"AddressBook",
"Addresses":[
{
"id":"1",
"NickName":"Rahul",
"ContactName":"Dravid",
"Company":"Cricket",
"City":"Indore",
"Country":"India",
"Type":"Address"
},
{
"id":"2",
"NickName":"Sachin",
"ContactName":"Tendulkar",
"Company":"Cricket",
"City":"Mumbai",
"Country":"India",
"Type":"Address"
}
]
}
I want to extract the data from the id = 1 using the JSON array, but I am not sure how to use the syntax or some other way the code I have is this :
JSONParser jsonParser = new JSONParser();
FileReader reader = new FileReader("AddressBook.json");
Object obj = jsonParser.parse(reader);
address = (JSONArray)obj;
You have to loop through the "Addresses" array.
JSONObject addressBook = (JSONObject) jsonParser.parse(reader);
JSONArray addresses = (JSONArray) addressBook.get("Addresses");
JSONObject address = null;
for (Object find : addresses) {
if (((JSONObject) find).get("id").equals("1")) {
address = (JSONObject) find;
}
}
System.out.println(address.toJSONString());
Output
{"Company":"Cricket","Type":"Address","Country":"India","id":"1","City":"Indore","NickName":"Rahul","ContactName":"Dravid"}
Below is the sample code:
import org.json.JSONArray
import org.json.JSONObject
JSONObject jsonObject = new JSONObject("{\"Status\":200,\"Description\":\"Success\",\"Result\":\"{\\\"Id\\\":\\\"ABCD123\\\",\\\"clientId\\\":\\\"0c34c71c\\\",\\\"status\\\":\\\"Finished\\\",\\\"message\\\":\\\"Done\\\",\\\"type\\\":\\\"registration\\\"}\"}")
/*
here I want to do something like:
JSONObject innerJsonObj = (JSONObject) jsonObject.get("Result");
String id = innerJsonObj.get("clientId");
*/
On executing JSONObject innerJsonObj = (JSONObject) jsonObject.get("Result"); - it gives:
Exception in thread "main" java.lang.ClassCastException: Cannot cast object '{"Id":"ABCD123","clientId":"0c34c71c","status":"Finished","message":"Done","type":"registration"}' with class 'java.lang.String' to class 'org.json.JSONObject'
So what modification I need to do for fetching the values present in nested JsonObject( i.e Result)
Your JSON:
{
"Status": 200,
"Description": "Success",
"Result": "{\"Id\":\"ABCD123\",\"clientId\":\"0c34c71c\",\"status\":\"Finished\",\"message\":\"Done\",\"type\":\"registration\"}"
}
As you can see, the value of Result is a string, not a JSON object.
So you'd need to create a new JSONObject from that string:
JSONObject jsonObject = new JSONObject("{\"Status\":200,\"Description\":\"Success\",\"Result\":\"{\\\"Id\\\":\\\"ABCD123\\\",\\\"clientId\\\":\\\"0c34c71c\\\",\\\"status\\\":\\\"Finished\\\",\\\"message\\\":\\\"Done\\\",\\\"type\\\":\\\"registration\\\"}\"}");
JSONObject innerJsonObj = new JSONObject(jsonObject.getString("Result"));
String id = innerJsonObj.getString("clientId");
I need to create in a Java (Android) a JSONObject/JSONArray with the exact following structure:
{
"listId":
[
"c02bc683-fcd7-47a5-b157-853e26ed099e",
"f8e1c9d7-ae45-4433-a315-726c1d912d09"
]
}
Can somebody help me on this please?
EDIT:
What i have is this:
JSONArray obj = new JSONArray();
JSONObject jsonObject = new JSONObject();
jsonObject.put("listId", folderId);
obj.put(jsonObject);
JSONObject json = new JSONObject();
json.put("id", obj);
But this produces something like:
{
"listId":
[
{"id":"c02bc683-fcd7-47a5-b157-853e26ed099e"},
{"id":"f8e1c9d7-ae45-4433-a315-726c1d912d09"}
]
}
Thanks
You've got your array creation a bit mixed up. What you really want is an object holding an array of string, but what you're doing is creating an array of JSONObject.
Try this instead:
String[] arr = { "c02bc683-fcd7-47a5-b157-853e26ed099e", "f8e1c9d7-ae45-4433-a315-726c1d912d09" };
JSONArray jsonArray = new JSONArray(arr);
JSONObject json = new JSONObject();
json.put("listId", jsonArray);
System.out.println(json); // {"listId":["c02bc683-fcd7-47a5-b157-853e26ed099e","f8e1c9d7-ae45-4433-a315-726c1d912d09"]}
I am using the following library to parse an object:
{"name": "web", "services": []}
And the following code
import com.json.parsers.JSONParser;
JSONParser parser = new JSONParser();
Object obj = parser.parseJson(stringJson);
when the array services is empty, it displays the following error
#Key-Heirarchy::root/services[0]/ #Key:: Value is expected but found empty...#Position::29
if the array services has an element everything works fine
{"name": "web", "services": ["one"]}
How can I fix this?
Thanks
Try using org.json.simple.parser.JSONParser
Something like this:
JSONParser parser = new JSONParser();
JSONObject jsonObject = (JSONObject) parser.parse(stringJson);
Now to access the fields, you can do this:
JSONObject name = jsonObject.get("name"); //gives you 'web'
And services is a JSONArray, so fetch it in JSONArray. Like this:
JSONArray services = jsonObject.get("services");
Now, you can iterate through this services JSONArray as well.
Iterator<JSONObject> iterator = services.iterator();
// iterate through json array
while (iterator.hasNext()) {
// do something. Fetch fields in services array.
}
Hope this would solve your problem.
Why do you need parser?
try this:-
String stringJson = "{\"name\": \"web\", \"services\": []}";
JSONObject obj = JSONObject.fromObject(stringJson);
System.out.println(obj);
System.out.println(obj.get("name"));
System.out.println(obj.get("services"));
JSONArray arr = obj.getJSONArray("services");
System.out.println(arr.size());
I solve the problen with https://github.com/ralfstx/minimal-json
Reading JSON
Read a JSON object or array from a Reader or a String:
JsonObject jsonObject = JsonObject.readFrom( jsonString );
JsonArray jsonArray = JsonArray.readFrom( jsonReader );
Access the contents of a JSON object:
String name = jsonObject.get( "name" ).asString();
int age = jsonObject.get( "age" ).asInt(); // asLong(), asFloat(), asDouble(), ...
Access the contents of a JSON array:
String name = jsonArray.get( 0 ).asString();
int age = jsonArray.get( 1 ).asInt(); // asLong(), asFloat(), asDouble(), ...
This question already has answers here:
Accessing members of items in a JSONArray with Java
(6 answers)
Closed 6 years ago.
I am in a bit of a fix regarding the JSONObject that I am getting as a response from the server.
jsonObj = new JSONObject(resultString);
JSONObject sync_reponse = jsonObj.getJSONObject("syncresponse");
String synckey_string = sync_reponse.getString("synckey");
JSONArray createdtrs_array = sync_reponse.getJSONArray("createdtrs");
JSONArray modtrs_array = sync_reponse.getJSONArray("modtrs");
JSONArray deletedtrs_array = sync_reponse.getJSONArray("deletedtrs");
String deleted_string = deletedtrs_array.toString();
{"syncresponse":{"synckey":"2011-09-30 14:52:00","createdtrs":[],"modtrs":[],"deletedtrs":[{"companyid":"UTB17","username":"DA","date":"2011-09-26","reportid":"31341"}]
as you can see in the response that I am getting I am parsing the JSONObject and creating syncresponse, synckey as a JSON object createdtrs, modtrs, deletedtrs as a JSONArray. I want to access the JSONObject from deletedtrs, so that I can split them apart and use the values. i.e I want to extract companyid, username, date etc.
How can I go about this ?
Thanks for your input.
JSONArray objects have a function getJSONObject(int index), you can loop through all of the JSONObjects by writing a simple for-loop:
JSONArray array;
for(int n = 0; n < array.length(); n++)
{
JSONObject object = array.getJSONObject(n);
// do some stuff....
}
Here is your json:
{
"syncresponse": {
"synckey": "2011-09-30 14:52:00",
"createdtrs": [
],
"modtrs": [
],
"deletedtrs": [
{
"companyid": "UTB17",
"username": "DA",
"date": "2011-09-26",
"reportid": "31341"
}
]
}
}
and it's parsing:
JSONObject object = new JSONObject(result);
String syncresponse = object.getString("syncresponse");
JSONObject object2 = new JSONObject(syncresponse);
String synckey = object2.getString("synckey");
JSONArray jArray1 = object2.getJSONArray("createdtrs");
JSONArray jArray2 = object2.getJSONArray("modtrs");
JSONArray jArray3 = object2.getJSONArray("deletedtrs");
for(int i = 0; i < jArray3 .length(); i++)
{
JSONObject object3 = jArray3.getJSONObject(i);
String comp_id = object3.getString("companyid");
String username = object3.getString("username");
String date = object3.getString("date");
String report_id = object3.getString("reportid");
}
JSONArray deletedtrs_array = sync_reponse.getJSONArray("deletedtrs");
for(int i = 0; deletedtrs_array.length(); i++){
JSONObject myObj = deletedtrs_array.getJSONObject(i);
}
{"syncresponse":{"synckey":"2011-09-30 14:52:00","createdtrs":[],"modtrs":[],"deletedtrs":[{"companyid":"UTB17","username":"DA","date":"2011-09-26","reportid":"31341"}]
The get companyid, username, date;
jsonObj.syncresponse.deletedtrs[0].companyid
jsonObj.syncresponse.deletedtrs[0].username
jsonObj.syncresponse.deletedtrs[0].date
start from
JSONArray deletedtrs_array = sync_reponse.getJSONArray("deletedtrs");
you can iterate through JSONArray and use values directly or create Objects of your own type
which will handle data fields inside of each deletedtrs_array member
Iterating
for(int i = 0; i < deletedtrs_array.length(); i++){
JSONObject obj = deletedtrs_array.getJSONObject(i);
Log.d("Item no."+i, obj.toString());
// create object of type DeletedTrsWrapper like this
DeletedTrsWrapper dtw = new DeletedTrsWrapper(obj);
// String company_id = obj.getString("companyid");
// String username = obj.getString("username");
// String date = obj.getString("date");
// int report_id = obj.getInt("reportid");
}
Own object type
class DeletedTrsWrapper {
public String company_id;
public String username;
public String date;
public int report_id;
public DeletedTrsWrapper(JSONObject obj){
company_id = obj.getString("companyid");
username = obj.getString("username");
date = obj.getString("date");
report_id = obj.getInt("reportid");
}
}
When using google gson library.
var getRowData =
[{
"dayOfWeek": "Sun",
"date": "11-Mar-2012",
"los": "1",
"specialEvent": "",
"lrv": "0"
},
{
"dayOfWeek": "Mon",
"date": "",
"los": "2",
"specialEvent": "",
"lrv": "0.16"
}];
JsonElement root = new JsonParser().parse(request.getParameter("getRowData"));
JsonArray jsonArray = root.getAsJsonArray();
JsonObject jsonObject1 = jsonArray.get(0).getAsJsonObject();
String dayOfWeek = jsonObject1.get("dayOfWeek").toString();
// when using jackson library
JsonFactory f = new JsonFactory();
ObjectMapper mapper = new ObjectMapper();
JsonParser jp = f.createJsonParser(getRowData);
// advance stream to START_ARRAY first:
jp.nextToken();
// and then each time, advance to opening START_OBJECT
while (jp.nextToken() == JsonToken.START_OBJECT) {
Map<String,Object> userData = mapper.readValue(jp, Map.class);
userData.get("dayOfWeek");
// process
// after binding, stream points to closing END_OBJECT
}
Make use of Android Volly library as much as possible. It maps your JSON reponse in respective class objects. You can add getter setter for that response model objects. And then you can access these JSON values/parameter using .operator like normal JAVA Object. It makes response handling very simple.