从java中的json中删除重复的key和value

import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.ObjectMapper;

import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;

public class JsonDuplicateRemoval {
    public static void main(String[] args) {
        String jsonStr = "{\"name\":\"John\",\"age\":30,\"name\":\"Doe\",\"email\":\"john.doe@example.com\"}";

        try {
            // 解析JSON数据
            ObjectMapper objectMapper = new ObjectMapper();
            JsonNode jsonNode = objectMapper.readTree(jsonStr);

            // 创建一个Map来存储唯一的key和value
            Map<String, JsonNode> uniqueMap = new HashMap<>();

            // 遍历JSON数据
            Iterator<Map.Entry<String, JsonNode>> fields = jsonNode.fields();
            while (fields.hasNext()) {
                Map.Entry<String, JsonNode> entry = fields.next();
                String key = entry.getKey();
                JsonNode value = entry.getValue();

                // 检查是否已经存在相同的key和value
                if (!uniqueMap.containsValue(value)) {
                    uniqueMap.put(key, value);
                }
            }

            // 构建新的JSON数据
            ObjectMapper newObjectMapper = new ObjectMapper();
            String newJsonStr = newObjectMapper.writeValueAsString(uniqueMap);

            System.out.println("原始JSON数据：" + jsonStr);
            System.out.println("删除重复的key和value后的JSON数据：" + newJsonStr);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}