Jackson将子JSON反序列化为父属性

import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
import com.fasterxml.jackson.databind.deser.std.StdDeserializer;
import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.DeserializationContext;

import java.io.IOException;

class Parent {
    private String name;

    public String getName() {
        return name;
    }
}

class Child extends Parent {
    @JsonDeserialize(using = ChildDeserializer.class)
    private String childName;
    
    public String getChildName() {
        return childName;
    }
}

class ChildDeserializer extends StdDeserializer<String> {
    public ChildDeserializer() {
        this(null);
    }

    public ChildDeserializer(Class<?> vc) {
        super(vc);
    }

    @Override
    public String deserialize(JsonParser p, DeserializationContext ctxt) throws IOException, JsonProcessingException {
        // 解析子JSON的字段，并将其赋值给childName属性
        // 在这里可以根据具体需求实现逻辑
        return p.getValueAsString();
    }
}

public class Main {
    public static void main(String[] args) throws JsonProcessingException {
        String json = "{\"name\":\"parent\",\"childName\":\"child\"}";

        ObjectMapper mapper = new ObjectMapper();
        Parent parent = mapper.readValue(json, Parent.class);

        System.out.println(parent.getName());  // 输出：parent
        // 这里访问的是父类的属性，但实际上是从子JSON中反序列化得到的
    }
}