package com.pjb.utils;
 
import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.node.ObjectNode;
 
/**
 * Jackson工具類
 * @author pan_junbiao
 **/
public class JacksonUtil
{
    private static ObjectMapper mapper = new ObjectMapper();
 
    /**
     * 合并 JSON 數(shù)據(jù)
     * @return 合并后的 JsonNode 對象
     */
    public static JsonNode mergeJsonNode(JsonNode mainNode, JsonNode updateNode)
    {
        //參數(shù)校驗
        if (mainNode == null && updateNode == null)
        {
            return null;
        }
 
        if (mainNode == null)
        {
            return updateNode;
        }
 
        if (updateNode == null)
        {
            return mainNode;
        }
 
        if (mainNode.isObject() && updateNode.isObject())
        {
            ObjectNode mergedNode = (ObjectNode) mainNode;
            updateNode.fields().forEachRemaining(entry -> {
                String key = entry.getKey();
                JsonNode value = entry.getValue();
                if (mergedNode.has(key))
                {
                    mergedNode.set(key, mergeJsonNode(mergedNode.get(key), value));
                } else
                {
                    mergedNode.set(key, value);
                }
            });
            return mergedNode;
        } else
        {
            // 非對象類型直接覆蓋（如數(shù)組、基本類型）
            return updateNode;
        }
    }
 
    /**
     * 合并 JSON 數(shù)據(jù)
     * @return 合并后的 JSON 字符串
     */
    public static String mergeJsonString(String mainJson, String updateJson)
    {
        //參數(shù)校驗
        if ((mainJson == null || mainJson.length() == 0) && (updateJson == null || updateJson.length() == 0))
        {
            return null;
        }
 
        if (mainJson == null || mainJson.length() == 0)
        {
            return updateJson;
        }
 
        if (updateJson == null || updateJson.length() == 0)
        {
            return mainJson;
        }
 
        try
        {
            //合并 JSON 數(shù)據(jù)
            JsonNode mainNode = mapper.readTree(mainJson);
            JsonNode updateNode = mapper.readTree(updateJson);
            JsonNode resultNode = mergeJsonNode(mainNode, updateNode);
            return mapper.writeValueAsString(resultNode);
        } catch (Exception e)
        {
            e.printStackTrace();
        }
        return null;
    }
}

/**
 * 合并 JSON 數(shù)據(jù)
 */
@Test
public void mergeJsonTest()
{
    try
    {
        String mainNode = "{\n" +
                "  \"userId\": 1,\n" +
                "  \"userName\": \"pan_junbiao的博客\"\n" +
                "}";
 
        String updateNode = "{\n" +
                "  \"userName\": \"pan_junbiao的博客_001\",\n" +
                "  \"blogName\": \"您好，歡迎訪問 pan_junbiao的博客\",\n" +
                "  \"blogUrl\": \"https://blog.csdn.net/pan_junbiao\",\n" +
                "  \"hobbies\": [\"游泳\", \"籃球\", \"足球\"]\n" +
                "}";
 
        //合并 JSON 數(shù)據(jù)
        String result = JacksonUtil.mergeJsonString(mainNode, updateNode);
 
        //打印結(jié)果
        System.out.println(result);
    } catch (Exception ex)
    {
        ex.printStackTrace();
    }
}