杰克逊:将表示单字段POJO的Map<String，Object>的JSON转换为字段值的Map<String，String>？

import com.fasterxml.jackson.databind.ObjectMapper;

public class JsonConverter {
    public static void main(String[] args) {
        // 假设输入的JSON字符串为jsonString
        String jsonString = "{\"field1\": \"value1\", \"field2\": 123}";

        // 创建ObjectMapper对象
        ObjectMapper objectMapper = new ObjectMapper();

        try {
            // 将JSON字符串转换为Map<String, Object>
            Map<String, Object> jsonMap = objectMapper.readValue(jsonString, new TypeReference<Map<String, Object>>() {});

            // 创建用于存储字段值的Map<String, String>
            Map<String, String> fieldValueMap = new HashMap<>();

            // 遍历jsonMap，将字段值转换为String类型并存储到fieldValueMap中
            for (Map.Entry<String, Object> entry : jsonMap.entrySet()) {
                String fieldName = entry.getKey();
                Object fieldValue = entry.getValue();
                String fieldValueString = objectMapper.writeValueAsString(fieldValue);
                fieldValueMap.put(fieldName, fieldValueString);
            }

            // 输出转换后的字段值Map<String, String>
            System.out.println(fieldValueMap);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}