I created Linq to SQL classes and override ToString method, but when I get object of class and call ToString method it returns full type of object as string. So, maybe Linq to SQL overrides this method in aother place? And how can I use method, overrided by myself? (I need exacly ToString method, not any other)
You're modifying generated files, which means re-generating the files will remove your modifications.
Don't modify the generated files. Note that the generated objects are partial classes, so you can modify them by creating separate files with partial classes of the same name. Something like this:
namespace MCN.Web
{
public partial class Mod
{
public override string ToString()
{
return Name;
}
}
}
Since it's a separate file, it won't be overwritten when generating the code.
Related
I have a BaseClass and bunch of derived classes.
I also have List<BaseClass> that contains objects from those derived classes.
When I do JSONUtility.ToJson(List<BaseClass>) I get only properties of BaseClass and not derived classes.
And well... I guess it is logical, but can't I force it to use derived class if there's a one or JSONUtility isn't capable of it? So I need to write custom logic for that?
Thanks!
Very probably JSONUtility.ToJson(List<BaseClass>) gets the elements you need with reflection, so the object returned is based on the incoming type.
I would try to obtain the jsons one by one and combine them in the logic, pre casting each of the types. Not tested nor debugged, just an starting point idea to move on:
string jsons;
foreach (var baseClass in baseClassList) {
Type specificType = baseClass.GetType();
string jsonString = JsonUtility.ToJson((specificType)baseClass)
jsons = "[" + string.Join(",", jsonstring) + "]";
}
I faced the same issue, to be honest JsonUtility is not good option for working with List.
My recommendations:
Use array instead of list with this helper class
or Newtonsoft Json Unity Package
I also needed JSON serialization, to call a REST json API, and I suggest to avoid JSONUtility.
It doesn't handle lists or dictionaries, as you saw.
Also it cannot serialize properties defined with { get; set; }, only fields, which is not blocking but not very convenient.
I agree with the recommendation above, just use Newtonsoft. It can serialize anything, and you will also benefit of the Serialization Settings (you can for example setup the contract resolver to convert all property names to snake_case...). See https://www.newtonsoft.com/json/help/html/SerializationSettings.htm
I'm trying to figure out how to adjust the way spring/jackson convert a JSON string (stored in a file) into various POJOs. For example, if I have this JSON:
{
"rates":{
"EURUSD":5.4321,
"USDHKD":1.2345
}
}
I actually want to get an instance of my 'Rates' class. Inside that I want a List containing each individual rate.
In my spring config file I created this entry:
#Bean
public ObjectMapper jsonObjectMapper() {
return new MappingJackson2HttpMessageConverter().getObjectMapper();
}
And in my service class I did this:
#Autowired
ObjectMapper jsonObjectMapper;
public Rates currentRates() {
Resource resource = this.ctx.getResource("classpath:stub/data/rates/Rates-01.json");
return this.jsonObjectMapper.readValue(resource.getURL(), Rates.class);
}
The problem is that I am trying to figure out how to take the Map containing the currencies as a single key, break those currencies in two and then create a RateEntry object containing the two currencies and the rate, before populating a list in the Rates class.
I've been looking at Spring's Conversion Service with the idea to define a converter that maps the Map to a list. i.e. this signature: Converter<Map<String, BigDecimal>, List<Rate>>. However this is based on the assumption that the JSON is first converted to standard types before the conversion service is called. An assumption I now think is incorrect.
So I'm now trying to figure out if I need to register some sort of custom ObjectMapper to handle reading directly from the JSON String data. But that sounds like over kill as I only want to adjust part of the object graph, and let the default converters handle the rest.
Any pointers appreciated. Thanks.
Ok, Jackson tries to stay away from structural transformations (since it's a quick-sand pit with unlimited number of general permutations). But it might be possible to use some existing features to do what you want.
First: to use Object key to indicate type, you will probably want to enable polymorphic type handling with "as object wrapper" inclusion.
So add something like:
#JsonTypeInfo(as=Include.WRAPPER_OBJECT)
for your Rates class declaration.
As to converting values into list; this might work by defining "any-setter" (see http://www.cowtowncoder.com/blog/archives/2011/07/entry_458.html), something like:
#JsonAnySetter
public void set(String key, Double value) // or "Object value")
{
list.add(new Rate(key, value));
}
I hope this helps.
Until now I was using serializable for saving and loading data, but now I have switched to JSON. And as soon as I have started there is a problem. Json will not save me any class. I was trying to save standalone Variables.class. This class contains various static data - player type string, bonus type strings, scores. Then I did create private class in class, then class in method, but nothing. Output od System.out.println(json) is always just {}.
For example this was my last attempt to make things work:
public static void saveAVD() {
Variables v = new Variables();
String json = new Json().toJson(v);
System.out.println(json);
file.writeString(json.prettyPrint(json), false);
}
Note: File variable is located in local bin folder. Inside that file are also just two empty bracelets ({})
Any advice?
(Credit to noone, who answered this in a comment).
JSON will, by default, not serialize static fields. The quickest way to get the behavior you want would probably be to convert the Variables class into a singleton.
I'm trying to change the (de)serialization of a list in one of my classes.
the objects in the list shall be serialised as int (their jpa id) and deserialised accordingly. serialization is simple.
for the deserialization i have a class that can translate the id into the object if id and class are known.
How do i get the necessary class from jackson? all default jackson serialisers have a constructor like this: protected StdDeserialiser(Class<?> vc) so the information is present somewhere.
is there a way to access it during deserialisation?
or before the deserialiser is constructed by jackson?
or inside the HandlerInstantiator?
I only want to overwrite the default deseriliser for certain references so i can't just write a provider or a custom module.
I made it work from inside the deserializer with the help of the ContextDeserializer interface as this supplies the deserializer with the target property.
public JsonDeserializer<?> createContextual(DeserializationContext ctxt, BeanProperty property) throws JsonMappingException {
Class<?> vc = null;
if (property.getType().isCollectionLikeType()) {
vc = property.getType().getContentType().getRawClass();
} else {
vc = property.getType().getRawClass();
}
return new ResourcePathDeserializer(vc, converter);
}
This solution is not perfect as I only get the raw class of the return type or the generic (which might be a parent class or an interface) but that is enough for my requirements.
It would be better if I could access the "real" class that was resolved by Jackson, but for me this works.
First of all, there is nothing fancy about writing a Module: it is just a way for plugging things in, like custom (de)serializers. So no need to avoid that. And you will most like need to write a module to do what you want.
In general it is not a good idea to try to create "universal" serializers or deserializers, and it will probably run into problem. But it depends on what exactly you are trying to do.
Type information will either be:
Implicit from context: you are writing a (de)serializer for type T, and register it for it, so that's your type
Passed by Jackson when (de)serializer is being constructed, via Module interface: modules are asked if they happen to have a (de)serializer for type T. SimpleModule will only use basic Class-to-impl mapping (that's where "simple" comes from); but full custom Module has access to incoming type.
But I don't know if above will work for your use case. Type information must be available from static type (declared content type for the list).
Is there any way to change the FieldName Value for a property in a Viewmodel? I would like to use the standard naming convention for the property, but have the viewmodel return something else. This is important, because I have a json request that requires the properties to be in lowercase.
I have tried using both XMLAttributes, and DataMembers, but neither of those soultions worked. Those came from the following questions.
Serialize .Net object to json, controlled using xml attributes
JavaScriptSerializer.Deserialize - how to change field names
So, to reiterate, I need something like this
public string Start { get; set; }
to show up as
viewmodel.start
instead of
viewmodel.Start
when I am passing my viewmodel to the callback inside the getJson request
What about adding an extra property to your model?
public string start {get {return Start;}}