I have the following json data and i need to deserialize it. Btw i am using C# and i tried the following:
C#
// the data has been assigned to json variable
Result deserializedResult = JsonConvert.DeserializeObject<Result>(json);
Result class
private String _id = String.Empty;
private String[] _result = { };
private String _error = String.Empty;
public Result()
{
}
public String id
{
get { return _id; }
set { _id = value; }
}
public String[] result
{
get { return _result; }
set { _result = value; }
}
public String error
{
get { return _error; }
set { _error = value; }
}
JSon
{"id":1,"result":
[
{"id":12345,
"list_id":54321,
"is_test":false,
"type":"manual",
"creator_name":"Test Solutions"
},
{"id":54321,
"list_id":12345,
"is_test":false,
"type":"manual",
"creator_name":"Test Solutions"
}
],
"error":null}
ERROR
Additional information: Error reading string. Unexpected token: StartObject. Path 'result[0]', line 1, position 19.
I was missing something so obvious. Instead of another object e.g. Result class i was expecting an array. I fixed the issue editing Result property chaning
public String[] result { get; set; }
to
public List<Result> result { get; set; }
Thank you and sorry for bothering. Have a nice day
Related
Returns Json format data to me from an api.
However, the type of the "FuelType" property inside the object may be different. For example, 1 time comes as follows:
{
...
fuelType: "gasoline"
...
}}
But then it can happen:
{
...
fuelType: ["gasoline", "any"]
...
}}
If I set the "FuelType" property type on my model to a string, in the second case, Json will give me an error when it arrives, because it can't convert from array to string. No, if I set the type to an array, then, conversely, if a string arrives, it will issue an error because it cannot convert from a string to an array.
In this case, what should I put the "FuelType" property type in my model so that it does not make an error when deserializing?
It all depends on you,what type of value you want to receive?string or List?
I tried with the codes:
public class SomeModel
{
public SomeModel()
{
fuelType = new List<string>();
}
public int Id { get; set; }
public string Name { get; set; }
public List<string> fuelType { get; set; }
//you could move the codes to someservice
public List<string> someresult(string a)
{
var targetlist = new List<string>();
targetlist.Add(a);
return targetlist;
}
public List<string> someresult(List<string> a)
{
var targetlist = new List<string>();
targetlist.AddRange(a);
return targetlist;
}
}
[HttpPost]
public JsonResult SomeAction()
{
var somemodel = new SomeModel() { Id = 1, Name = "name" };
var somevalue = /*"a"*/new List<string>() { "a", "b", "c" };
var targetvalue = somemodel.someresult(somevalue);
somemodel.fuelType.AddRange(targetvalue);
return new JsonResult(somemodel);
}
Result:
try this
var fuelType = JsonConvert.DeserializeObject<MyClass>(json);
public class MyClass
{
[JsonProperty("fuelType")]
private JToken _fuelType;
[JsonIgnore]
public string[] fuelType
{
get {
if (_fuelType==null) return null;
return _fuelType is JArray ? _fuelType.ToObject<string[]>() : new string[] { (string)_fuelType }; }
set { _fuelType = JsonConvert.SerializeObject(value); }
}
}
I have a question about inserting a json formatted string into a json structure and having the final version be a combined JSON formatted string that can be serialized into a JSON structure. I am using the newtonsofts Json.NET
I have the following JSON structure:
public class ResponseJson
{
[JsonProperty(PropertyName = "header")]
public ResponseHeader responseHeader { get; set; }
[JsonProperty(PropertyName = "results")]
public string responseResults { get; set; }
}
public class ResponseHeader
{
[JsonProperty(PropertyName = "name")]
public string name { get; set; }
[JsonProperty(PropertyName = "version")]
public string version { get; set; }
}
In the code, I do the following:
ResponseJson responseJson = new ResponseJson();
responseJson.responseHeader = new ResponseHeader()
{
name = A_NAME,
version = A_VERSION
};
responseJson.responseResults = resultJson;
return JsonConvert.SerializeObject(responseJson, new JsonSerializerSettings { NullValueHandling = NullValueHandling.Ignore });
resultJson is a properly formatted JSON string (in this case, an array of objects, but could be anything JSON formatted). Right now, if i execute the code, I get the following (which is expected, since "results" is declared as a string):
{
"header":
{
"name":"abcd",
"version":"1.0"
},
"results":
"[{\"data\":{\"level\":\"100\"},\"code\":{\"value\":\"JBC\",\"type\":\"ev\"},\"time\":{\"start\":\"20\",\"end\":\"101\"}}]"
}
what I do need as an output is:
{
"header":
{
"name":"abcd",
"version":"1.0"
},
"results":
[
{
"data":
{
"level":"100"
},
"code":
{
"value":"JBC",
"type":"ev"
},
"time":
{
"start":"20",
"end":"101"
}
}
]
}
While you don't explain how you create your resultJson variable, it's implied from your code that you are double-serializing your results: you compute an array of "result" classes, serialize them to a JSON string, store the string in your ResponseJson class, and them serialize that in turn. The embedded JSON string then gets escaped as per the JSON standard, which is what you are seeing.
You need to avoid double-serializing your data, for instance by using the following data model:
public class ResponseJson<T>
{
[JsonProperty(PropertyName = "header")]
public ResponseHeader responseHeader { get; set; }
[JsonProperty(PropertyName = "results")]
public T responseResults { get; set; }
}
public static class ResponseJson
{
public static ResponseJson<T> Create<T>(T responseResults, ResponseHeader responseHeader)
{
return new ResponseJson<T> { responseResults = responseResults, responseHeader = responseHeader };
}
}
public class ResponseHeader
{
[JsonProperty(PropertyName = "name")]
public string name { get; set; }
[JsonProperty(PropertyName = "version")]
public string version { get; set; }
}
Then you would do:
var results = GetResults(); // Get your result data
var responseJson = ResponseJson.Create(results, new ResponseHeader()
{
name = A_NAME,
version = A_VERSION
});
return JsonConvert.SerializeObject(responseJson, new JsonSerializerSettings { NullValueHandling = NullValueHandling.Ignore });
If for whatever reason you must embed a previously serialized JSON string as JSON rather than as a string literal, you'll need to re-parse it back to a JToken:
string resultJson = GetResultJson(); // Get result json string.
var responseJson = ResponseJson.Create(JToken.Parse(resultJson), new ResponseHeader()
{
name = A_NAME,
version = A_VERSION
});
return JsonConvert.SerializeObject(responseJson, new JsonSerializerSettings { NullValueHandling = NullValueHandling.Ignore });
Json.NET will include the JToken in your outer JSON as nested JSON rather than as a string literal.
I want to deserialize json which returns different data for different parameters.
Mostly I get:
{"posts": [{ "id" : 1, "name":"post1" },{ "id" : 1, "name":"post1" }]}
But sometimes the data returned is
{"posts": false}
I want to deserialize this as the following class
public class GetReaderResponse
{
public IEnumerable<ReaderPost> posts {get; set;}
}
public class ReaderPost
{
public int id {get; set;}
public string name{get; set;}
}
I am using C#,json.net but not able to do this correctly.
Newtonsoft.Json.JsonConvert.DeserializeObject<GetReaderResponse>(dataString);
You could build a custom converter, but an easy way to handle this would be to write an error handler that detects errors with the posts property:
var settings = new JsonSerializerSettings();
settings.Error += (sender, args) =>
{
if (string.Equals("posts", args.ErrorContext.Path, StringComparison.OrdinalIgnoreCase))
{
var currentObject = args.CurrentObject as GetReaderResponse;
currentObject.posts = Enumerable.Empty<ReaderPost>();
args.ErrorContext.Handled = true;
}
};
GetReaderResponse resp =
JsonConvert.DeserializeObject<GetReaderResponse>(json, settings);
This sets posts to Enumerable.Empty<ReaderPost>. This is still a little unsatisfying because if any error occurs, the property will be set. You could build a full custom converter to do this as a more complete solution.
Here's a converter that will take care of this:
public class PostsConverter : JsonConverter
{
public override object ReadJson(
JsonReader reader,
Type objectType,
object existingValue,
JsonSerializer serializer)
{
JToken val = JValue.ReadFrom(reader);
object result = null;
if (val.Type == JTokenType.Array)
{
result = val.ToObject<IEnumerable<ReaderPost>>();
}
else if (val.Type == JTokenType.Boolean)
{
result = Enumerable.Empty<ReaderPost>();
}
return result;
}
public override void WriteJson(
JsonWriter writer,
object value,
JsonSerializer serializer)
{
throw new NotImplementedException();
}
public override bool CanConvert (Type type)
{
return typeof(IEnumerable<ReaderPost>).IsAssignableFrom(type);
}
public override bool CanRead
{
get { return true; }
}
}
Usage:
var settings = new JsonSerializerSettings();
settings.Converters = new [] { new PostsConverter() };
GetReaderResponse resp =
JsonConvert.DeserializeObject<GetReaderResponse>(json, settings);
Example: https://dotnetfiddle.net/i9CXwp
By using JSON.NETs built in LINQ to JSON, you can try someting like this:
JObject jObject = JObject.Parse(json);
GetReaderResponse response = new GetReaderResponse();
if (jObject["posts"] is JArray)
response = jObject.ToObject<GetReaderResponse>();
// Do something with the response object.
where json variable is the json string you need to deserialize.
try this:
public class GetReaderResponse
{
public bool posts { get; set; }
public ReaderPost[] post { get; set; }
}
After reading #Ilija's comment I think I might have found a answer. I did not want not use string literals so I modified my class GetReaderResponse to look like below:
public class GetReaderResponse
{
public dynamic posts {get; set;}
public IEnumerable<ReaderPost> Posts
{
get
{
if (posts is bool )
return new ReaderPost[0];
return posts.ToObject<IEnumerable<ReaderPost>>();
}
}
}
Does this sound fine or does it look messy?
This is Json Object
[
{
"UserId":"demouser1",
"Catagories":[
{
"CatagoryName":"Entertainment",
"Persent":"25"
},
{
"CatagoryName":"Household",
"Persent":"25"
},
{
"CatagoryName":"Movie",
"Persent":"25"
},
{
"CatagoryName":"Misc",
"Persent":"25"
}
],
"RequestId":null,
"ResponseStatus":false,
"Token":null
}
]
Used The Following approach to parse the above Json
public class CategoryEntity {
private String CatagoryName;
private String Persent;
public String getCatagoryName() {
return CatagoryName;
}
public void setCatagoryName(String catagoryName) {
CatagoryName = catagoryName;
}
public String getPersent() {
return Persent;
}
public void setPersent(String persent) {
Persent = persent;
}
}
import java.util.List;
public class Entity {
private String UserId;
public String getUserId() {
return UserId;
}
public void setUserId(String userId) {
UserId = userId;
}
public List<CategoryEntity> getListCatagories() {
return ListCatagories;
}
public void setListCatagories(List<CategoryEntity> listPMMCatagories) {
ListCatagories = listPMMCatagories;
}
public String getRequestId() {
return RequestId;
}
public void setRequestId(String requestId) {
RequestId = requestId;
}
public boolean isResponseStatus() {
return ResponseStatus;
}
public void setResponseStatus(boolean responseStatus) {
ResponseStatus = responseStatus;
}
private List<CategoryEntity> ListCatagories;
private String RequestId;
private String Token;
public String getToken() {
return Token;
}
public void setToken(String token) {
Token = token;
}
private boolean ResponseStatus;
}
And
Following approach to convert the json object to corresponding object
Gson gson =new Gson();
JsonPrimitive listCatagoriesElement= element.getAsJsonPrimitive();
System.out.println("listCatagoriesElement.getAsString()>>"+listCatagoriesElement.getAsString());
sysout prints: listCatagoriesElement.getAsString()>>[{"UserId":"user1","ListCatagories":[{"CatagoryName":"Entertainment","Persent":"25"},{"CatagoryName":"Household","Persent":"25"},{"CatagoryName":"Movie","Persent":"25"},{"CatagoryName":"Misc","Persent":"25"}],"RequestId":null,"ResponseStatus":false,"Token":null}]
Entity entity = gson.fromJson(listCatagoriesElement, Entity.class);
Any ideas how should I fix it?
Thanks!
Your class CategoryEntity is correct, but in your class Entity, the attribute ListCatagories should be called Catagories to match the name in the JSON!
Apart from that, in order to parse the JSON you'd better do something like this:
Gson gson = new Gson();
Type listType = new TypeToken<List<Entity>>() {}.getType();
List<Entity> entities = gson.fromJson(yourJsonString, listType);
So you'll have a List containing just one Entity object, and you can access the values just with:
String catagoryNameI = entities.get(0).getCatagories().get(i).getCatagoryName();
String persentI = entities.get(0).getCatagories().get(i).getPersent();
You have to do this because your whole JSON response is an array, surrounded by [ ... ], so you need to parse it into some List...
So my entities look like this:
public class HappyClass<T>
{
private String id;
prviate int ver;
private Object obj;
public String getId()
{
return this.id;
}
public void setId( String id )
{
this.id = id;
}
public int getVer()
{
return this.ver;
}
public void setVer( int ver )
{
this.ver = ver;
}
#JsonTypeInfo( use = Id.NONE )
public T getObj()
{
return obj;
}
public void setObj( T obj )
{
this.obj = obj;
}
}
public class HappyGeneric
{
private String someStuff();
public String getSomeStuff()
{
return this.someStuff();
}
public void setSomeStuff( String someStuff )
{
this.someStuff = someStuff;
}
}
If I instantiate a class like this:
HappyClass<HappyGeneric> hc = new HappyClass<HappyGeneric>();
If I send it to Spring in a #ResponseBody it returns this:
{
"id" : "iamsomeid",
"ver" : 123,
"obj" : {
"someStuff" : "iamsomestuff"
}
}
However, when Spring and/or Jackson attempts to unmarshal the same JSON, it figures out that the main class is a HappyClass, however, the getObj() it unmarshals to a LinkedHashMap and not a HappyGeneric no matter what I seem to annotate it with.
Anybody have any ideas how I can force Jackson to unmarshal that generic to the original class?
Thanks!
EDIT: I'm aware I can call mapper.convertValue( blah.getObj(), HappyGeneric.class ) and get the object out that way-- I was hoping to get Spring to figure it out automatically (through annotations, for example).