Java JsonLocationInstantiator-class And Method Code Example
Here is an example of how to use the JsonLocationInstantiator
class from the Jackson Databind library to deserialize a custom object from JSON with a custom location instantiator:
import com.fasterxml.jackson.databind.DeserializationContext;
import com.fasterxml.jackson.databind.JsonDeserializer;
import com.fasterxml.jackson.databind.JsonMappingException;
import com.fasterxml.jackson.databind.deser.std.StdDeserializer;
import com.fasterxml.jackson.databind.deser.std.JsonLocationInstantiator;
import com.fasterxml.jackson.databind.introspect.AnnotatedWithParams;
public class CustomLocationInstantiator extends JsonLocationInstantiator {
@Override
public Object createUsingDefault(DeserializationContext ctxt) throws JsonMappingException {
return new MyLocation();
}
@Override
public AnnotatedWithParams getDefaultCreator() {
return null;
}
@Override
public Object createUsingDelegate(DeserializationContext ctxt, Object delegate) throws JsonMappingException {
return new MyLocation();
}
@Override
public AnnotatedWithParams getDelegateCreator() {
return null;
}
}
You can then use this custom location instantiator by registering it with the ObjectMapper:
ObjectMapper mapper = new ObjectMapper();
SimpleModule module = new SimpleModule();
module.setLocationInstantiator(MyLocation.class, new CustomLocationInstantiator());
mapper.registerModule(module);
Then you can deserialize your JSON to MyLocation object as follow:
MyLocation location = mapper.readValue(jsonString, MyLocation.class);
Please note that the above example is just a skeleton code, you may need to handle the exception and add proper validation based on your use case.
You also need to make sure that the MyLocation class has the proper constructor or factory method that the instantiator can use to create the object.