Jackson动态枚举反序列化：多态注解与自定义工厂方法实践

// 公共枚举接口
public interface MyEnumType {
    // 接口本身可以为空，或定义一些通用方法
}

// 第一个枚举类型
public enum MyEnum1 implements MyEnumType {
    Red, Green, Blue;
}

// 第二个枚举类型
public enum MyEnum2 implements MyEnumType {
    Circle, Square, Triangle;
}

import com.fasterxml.jackson.annotation.JsonProperty; // 可选，用于明确JSON属性名

public class MyObject {
    @JsonProperty("myEnum") // 明确JSON属性名为"myEnum"
    private MyEnumType myEnum;

    // 无参构造函数（Jackson反序列化需要）
    public MyObject() {}
    // 全参构造函数
    public MyObject(MyEnumType myEnum) { this.myEnum = myEnum; }

    // Getter和Setter方法
    public MyEnumType getMyEnum() { return myEnum; }
    public void setMyEnum(MyEnumType myEnum) { this.myEnum = myEnum; }

    @Override
    public String toString() {
        return "Enum value is " + myEnum;
    }
}

import com.fasterxml.jackson.annotation.JsonSubTypes;
import com.fasterxml.jackson.annotation.JsonTypeInfo;
import com.fasterxml.jackson.annotation.JsonTypeInfo.Id;

@JsonTypeInfo(use = Id.NAME) // 使用名称作为类型标识符
@JsonSubTypes({
    @JsonSubTypes.Type(value = MyEnum1.class, name = "MyEnum1"), // MyEnum1 对应 "MyEnum1"
    @JsonSubTypes.Type(value = MyEnum2.class, name = "MyEnum2")  // MyEnum2 对应 "MyEnum2"
})
public interface MyEnumType {
}

import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;

public class DynamicEnumDeserializationExample {

    public static void main(String[] args) throws JsonProcessingException {
        ObjectMapper jsonMapper = new ObjectMapper();

        // 序列化 MyEnum1
        MyObject original1 = new MyObject(MyEnum1.Blue);
        String json1 = jsonMapper.writeValueAsString(original1);
        System.out.println("Serialized MyEnum1: " + json1);
        MyObject result1 = jsonMapper.readValue(json1, MyObject.class);
        System.out.println("Deserialized MyEnum1: " + result1);
        // 预期输出示例: Serialized MyEnum1: {"myEnum":{"@type":"MyEnum1","name":"Blue"}}
        // 预期输出示例: Deserialized MyEnum1: Enum value is Blue

        System.out.println("--------------------");

        // 序列化 MyEnum2
        MyObject original2 = new MyObject(MyEnum2.Triangle);
        String json2 = jsonMapper.writeValueAsString(original2);
        System.out.println("Serialized MyEnum2: " + json2);
        MyObject result2 = jsonMapper.readValue(json2, MyObject.class);
        System.out.println("Deserialized MyEnum2: " + result2);
        // 预期输出示例: Serialized MyEnum2: {"myEnum":{"@type":"MyEnum2","name":"Triangle"}}
        // 预期输出示例: Deserialized MyEnum2: Enum value is Triangle
    }
}

import com.fasterxml.jackson.annotation.JsonCreator;

public interface MyEnumType {

    @JsonCreator // 标记此方法为JSON创建器
    public static MyEnumType deserialize(String value) {
        MyEnumType result = null;

        // 尝试解析为MyEnum1
        try {
            result = MyEnum1.valueOf(value);
        } catch (IllegalArgumentException ex) {
            // 如果不是MyEnum1的值，则忽略异常，继续尝试
        }

        // 如果不是MyEnum1，则尝试解析为MyEnum2
        if (result == null) {
            try {
                result = MyEnum2.valueOf(value);
            } catch (IllegalArgumentException ex) {
                // 如果不是MyEnum2的值，则忽略异常
            }
        }

        // 如果仍然无法匹配，则抛出异常
        if (result == null) {
            throw new IllegalArgumentException(value + " does not match any known enum.");
        }
        return result;
    }
}

// MyObject 类定义与方法一相同
// import com.fasterxml.jackson.annotation.JsonProperty; // 可选

public class MyObject {
    @JsonProperty("myEnum")
    private MyEnumType myEnum;

    public MyObject() {}
    public MyObject(MyEnumType myEnum) { this.myEnum = myEnum; }

    public MyEnumType getMyEnum() { return myEnum; }
    public void setMyEnum(MyEnumType myEnum) { this.myEnum = myEnum; }

    @Override
    public String toString() {
        return "Enum value is " + myEnum;
    }
}

import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;

public class DynamicEnumCreatorDeserializationExample {

    public static void main(String[] args) throws JsonProcessingException {
        ObjectMapper jsonMapper = new ObjectMapper();

        // 模拟只包含字符串值的JSON
        String json1 = "{\"myEnum\":\"Blue\"}";
        System.out.println("JSON for MyEnum1: " + json1);
        MyObject result1 = jsonMapper.readValue(json1, MyObject.class);
        System.out.println("Deserialized MyEnum1: " + result1);
        // 预期输出: Deserialized MyEnum1: Enum value is Blue

        System.out.println("--------------------");

        String json