JackSonMixIn多态类型处理注释

Question

在下面的代码中，我尝试使用JackSonMixInAnnotations进行多态类型处理 但是我的代码没有用。

请建议我需要做哪些更改，以更正此代码。

我不想在Animal类中做任何改变。而且，像Dog类我可能有许多扩展Animal类的类。

代码应打印“Animal”（Dog或Elephant）类，具体取决于从客户端传递给MyController类中“test（）”的Animal对象的“type”字段。

客户端可以发送JSON，如：

“{\”id \“：\”DOG \“，\”type \“：\”dog \“，\”someAttrOfDog \“：\”someValue \“}”

import org.codehaus.jackson.annotate.JsonSubTypes;
import org.codehaus.jackson.annotate.JsonTypeInfo;

@JsonTypeInfo( use = JsonTypeInfo.Id.NAME,  include = JsonTypeInfo.As.PROPERTY, property = "type")
/*@JsonSubTypes({// @JsonSubTypes.Type(value = Dog.class, name = "dog") 


})*/
public abstract class Animal{

private String id;
private String type;


public String getId() {
    return id;
}
public void setId(String id) {
    this.id = id;
}
public String getType() {
    return type;
}
public void setType(String type) {
    this.type = type;
}

}


package com.Animal;

import org.codehaus.jackson.annotate.JsonTypeName;

@JsonTypeName("cat")
public class Cat extends Animal{
    String someAttrOfCat;

    public String getSomeAttrOfCat() {
        return someAttrOfCat;
    }

    public void setSomeAttrOfCat(String someAttrOfCat) {
        this.someAttrOfCat = someAttrOfCat;
    }
}




package com.Animal;

import org.codehaus.jackson.annotate.JsonTypeName;

@JsonTypeName("dog")
public class Dog extends Animal{

    private String someAttrOfDog;

    public String getSomeAttrOfDog() {
        return someAttrOfDog;
    }

    public void setSomeAttrOfDog(String someAttrOfDog) {
        this.someAttrOfDog = someAttrOfDog;
    }

}

package com.Animal;

import org.codehaus.jackson.annotate.JsonSubTypes;
import org.codehaus.jackson.annotate.JsonSubTypes.Type;

@JsonSubTypes (
    { @Type(value = Dog.class, name = "dog") }
    )
public class MixinDog {


}




package com.startUpClasses;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;

import org.codehaus.jackson.map.ObjectMapper;

import com.Animal.Animal;
import com.Animal.MixinDog;

public class StartApp extends HttpServlet{

    public void init() throws ServletException{ 
    System.out.println("---------In StartApp init------------");
    ObjectMapper mapper = new ObjectMapper();
    mapper.getSerializationConfig().addMixInAnnotations(Animal.class, MixinDog.class);
    System.out.println("---------In StartApp init1------------");
    mapper.getDeserializationConfig().addMixInAnnotations(Animal.class, MixinDog.class);
    System.out.println("---------In StartApp init2------------");
    }

}


import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.ResponseBody;

import com.Animal.Animal;

@Controller
public class MyController {


    @RequestMapping( value = "test",method = RequestMethod.POST)
    public  @ResponseBody String test(@RequestBody  Animal animal){

        System.out.println("In  Controller");
        System.out.println(animal.getClass());
        return "success";

   }
}

AnimalWithJsonType-servlet.xml中

<context:component-scan base-package="com.restcontrollers"/>
<mvc:annotation-driven />
</beans>

的web.xml

 <?xml version="1.0" encoding="UTF-8"?>
 <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"       xmlns="http://java.sun.com/xml/ns/javaee"    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" id="WebApp_ID" version="2.5">
  <display-name>AnimalWithJsonType</display-name>
  <welcome-file-list>
    <welcome-file>index.html</welcome-file>
    <welcome-file>index.htm</welcome-file>
    <welcome-file>index.jsp</welcome-file>
    <welcome-file>default.html</welcome-file>
    <welcome-file>default.htm</welcome-file>
    <welcome-file>default.jsp</welcome-file>
  </welcome-file-list>
  <servlet>
     <servlet-name>AnimalWithJsonType</servlet-name>
     <servlet-class>
          org.springframework.web.servlet.DispatcherServlet
     </servlet-class>
     <load-on-startup>0</load-on-startup>
     </servlet>
<servlet>
   <servlet-name>StartApp</servlet-name>
   <servlet-class>com.startUpClasses.StartApp</servlet-class>
   <load-on-startup>0</load-on-startup>
</servlet>  
<servlet-mapping>
   <servlet-name>AnimalWithJsonType</servlet-name>
   <url-pattern>/animals/*</url-pattern>
 </servlet-mapping>
</web-app>