使用Jackson构建动态POJO以处理不确定JSON键名和数量的数组变量

{
    "EU": [
        {
            "calId": "EU",
            "calDate": "2022-11-01",
            // ... 其他字段
        }
    ],
    "AU": [
        {
            "calId": "AU",
            "calDate": "2022-11-01",
            // ... 其他字段
        }
    ]
}

// 传统静态POJO示例 (存在局限性)
@Data
@AllArgsConstructor
@NoArgsConstructor
public class StaticIndexCalendarDateResponseBean {
    @JsonProperty("EU")
    private List<IndexCalendarDateResponseWrapper> EU;

    @JsonProperty("AU")
    private List<IndexCalendarDateResponseWrapper> AU;
    // 如果有其他动态键名，需要不断添加字段
}

// IndexCalendarDateResponseWrapper.java
@Data
@AllArgsConstructor
@NoArgsConstructor
public class IndexCalendarDateResponseWrapper {
    private String calId;
    private String calDate;
    private String prevBusinessDay;
    private String nextBusinessDay;
    private boolean businessDay;
    private boolean monthEndBusinessDay;
    // ... 其他字段
}

import com.fasterxml.jackson.annotation.JsonAnyGetter;
import com.fasterxml.jackson.annotation.JsonAnySetter;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class IndexCalendarDateResponseBean {
    // 使用Map来存储所有动态的键值对
    private Map<String, List<IndexCalendarDateResponseWrapper>> responseWrappers = new HashMap<>();

    /**
     * @JsonAnySetter 注解用于JSON反序列化。
     * 当Jackson解析JSON时，如果遇到在POJO中没有明确定义字段的属性，
     * 就会调用这个方法，将属性名作为key，属性值作为value添加到Map中。
     *
     * @param key   JSON属性名 (例如 "EU", "AU", "JU" 等)
     * @param value 对应属性的值 (例如 List<IndexCalendarDateResponseWrapper>)
     */
    @JsonAnySetter
    public void readResponseWrappers(String key, List<IndexCalendarDateResponseWrapper> value) {
        responseWrappers.put(key, value);
    }

    /**
     * @JsonAnyGetter 注解用于JSON序列化。
     * 当Jackson将POJO序列化为JSON时，它会调用这个方法，
     * 将Map中的所有键值对作为顶层属性添加到输出的JSON对象中。
     *
     * @return 包含所有动态属性的Map
     */
    @JsonAnyGetter
    public Map<String, List<IndexCalendarDateResponseWrapper>> writeResponseWrappers() {
        return responseWrappers;
    }

    // 可以根据需要添加其他业务逻辑方法或构造函数
}

import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.core.type.TypeReference; // 如果需要更复杂的类型

// 假设 responseString 是从API获取的JSON字符串
String responseString = "{\n" +
        "    \"EU\": [\n" +
        "        {\n" +
        "            \"calId\": \"EU\",\n" +
        "            \"calDate\": \"2022-11-01\",\n" +
        "            \"prevBusinessDay\": \"2022-11-01\",\n" +
        "            \"nextBusinessDay\": \"2022-11-01\",\n" +
        "            \"businessDay\": true,\n" +
        "            \"monthEndBusinessDay\": false\n" +
        "        }\n" +
        "    ],\n" +
        "    \"AU\": [\n" +
        "        {\n" +
        "            \"calId\": \"AU\",\n" +
        "            \"calDate\": \"2022-11-01\",\n" +
        "            \"prevBusinessDay\": \"2022-11-01\",\n" +
        "            \"nextBusinessDay\": \"2022-11-01\",\n" +
        "            \"businessDay\": true,\n" +
        "            \"monthEndBusinessDay\": false\n" +
        "        }\n" +
        "    ],\n" +
        "    \"JU\": [\n" + // 示例中新增的动态键
        "        {\n" +
        "            \"calId\": \"JU\",\n" +
        "            \"calDate\": \"2022-11-02\",\n" +
        "            \"prevBusinessDay\": \"2022-11-02\",\n" +
        "            \"nextBusinessDay\": \"2022-11-02\",\n" +
        "            \"businessDay\": true,\n" +
        "            \"monthEndBusinessDay\": false\n" +
        "        }\n" +
        "    ]\n" +
        "}";

ObjectMapper objectMapper = new ObjectMapper();
try {
    IndexCalendarDateResponseBean actualRIOutput = objectMapper.readValue(responseString, IndexCalendarDateResponseBean.class);

    // 访问动态数据
    Map<String, List<IndexCalendarDateResponseWrapper>> data = actualRIOutput.writeResponseWrappers(); // 或者直接访问内部的responseWrappers字段

    System.out.println("所有动态键名: " + data.keySet());
    for (Map.Entry<String, List<IndexCalendarDateResponseWrapper>> entry : data.entrySet()) {
        System.out.println("键: " + entry.getKey() + ", 值数量: " + entry.getValue().size());
        // 可以进一步处理 entry.getValue() 中的列表数据
    }

    // 序列化回JSON
    String serializedJson = objectMapper.writeValueAsString(actualRIOutput);
    System.out.println("\n序列化后的JSON:\n" + serializedJson);

} catch (Exception e) {
    e.printStackTrace();
}

import com.fasterxml.jackson.annotation.JsonInclude;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

// IndexCalendarDateResponseWrapper.java
@Data
@AllArgsConstructor
@NoArgsConstructor
@JsonInclude(JsonInclude.Include.NON_NULL) // 序列化时忽略值为null的字段
// @JsonInclude(JsonInclude.Include.NON_EMPTY) // 如果字段是集合、Map或字符串，且为空，则忽略
public class IndexCalendarDateResponseWrapper {
    private String calId;
    private String calDate;
    private String prevBusinessDay;
    private String nextBusinessDay;
    private boolean businessDay;
    private boolean monthEndBusinessDay;
    // ... 其他字段
}