Spring @ReponseBody @RequestBody with abstract class

Question

Suppose I have three classes.

public abstract class Animal {}  public class Cat extends Animal {}  public class Dog extends Animal {} 

Can I do something like this?

Input: a JSON which it is Dog or Cat

Output: a dog/cat depends on input object type

I don't understand why the following code doesn't work. Or should I use two separate methods to handle new dog and cat?

@RequestMapping(value = "/animal", method = RequestMethod.POST, produces = "application/json; charset=utf-8") private @ResponseBody <T extends Animal>T insertAnimal(@RequestBody T animal) {     return animal; } 

Error message:

HTTP Status 500 - Request processing failed; nested exception is java.lang.IllegalArgumentException: Type variable 'T' can not be resolved

Answer 1

ref link

I just found the answer myself and here is the reference link.

What I have done is added some code above the abstract class

import com.fasterxml.jackson.annotation.JsonSubTypes; import com.fasterxml.jackson.annotation.JsonTypeInfo; import com.fasterxml.jackson.annotation.JsonTypeInfo.*;  @JsonTypeInfo(use = Id.NAME, include = As.PROPERTY, property = "type") @JsonSubTypes({     @JsonSubTypes.Type(value = Cat.class, name = "cat"),     @JsonSubTypes.Type(value = Dog.class, name = "dog") }) public abstract class Animal{} 

Then in the json input in HTML,

var inputjson = {     "type":"cat",     //blablabla }; 

After submitting the json and finally in the controller,

@RequestMapping(value = "/animal", method = RequestMethod.POST, produces = "application/json; charset=utf-8", consumes=MediaType.APPLICATION_JSON_VALUE) public @ResponseBody insertanimal(@RequestBody Animal tmp) {     return tmp; } 

In this case variable tmp is automatically converted to a Dog or Cat object, depending on json input.