背景
之前有类似接口diff对比，数据对比的测试需求，涉及到json格式的数据对比，调研了几个大神们分享的代码，选了一个最符合自己需求的研究了下。
说明
这个对比方法，支持JsonObject和JsonArray类型的数据对比，支持：
-
深度的对比：list变化（个数、内容）、层级结构变化
-
字段的对比：新增、修改、删除数据可察觉，能找到对应的旧数据
-
支持特定字段忽略对比
输出的对比结果格式为：
源码分为JsonCompareUtils， JsonAndMapSortUtils两个类，对比入口是compareTwoJson方法
核心逻辑在JsonCompareUtils类中，JsonAndMapSortUtils主要做过程中的数据排序功能，相对独立。
上源码：
import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONArray;
import com.alibaba.fastjson.JSONObject;
import org.apache.commons.lang.ArrayUtils;
import org.apache.commons.lang.StringUtils;import java.util.HashMap;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.stream.Stream;public class JsonCompareUtils {//标志位：对json报文中含有JsonArray类型的数据是否进行排序private static boolean isSort;private Map<String, Object> oldJsonToMap = new LinkedHashMap<>();private Map<String, Object> newJsonToMap = new LinkedHashMap<>();//每一个实体里的排序字段private static Map<String, String> filedNameMap = new HashMap<>();static {filedNameMap.put("ojb1", "id");filedNameMap.put("ojb2", "id");}//可以跳过比对的字段private static String[] skipCompareFiledNameMap = {"createTime"};/*** 两json报文比对入口** @param oldJsonStr* @param newJsonStr* @return*/public String compare2Json(String oldJsonStr, String newJsonStr) {/*** 递归遍历json对象所有的key-value，以map形式的path:value进行存储* 然后对两个map进行比较*/convertJsonToMap(JSON.parseObject(oldJsonStr), "", false);convertJsonToMap(JSON.parseObject(newJsonStr), "", true);//获取比较结果Map<String, Object> differenceMap = compareTwoMaps(oldJsonToMap, newJsonToMap);String diffJsonResult = convertMapToJson(differenceMap);return diffJsonResult;}/*** 将json数据转换为map存储--用于后续比较map** @param json* @param root* @param isNew 区别新旧报文*/private void convertJsonToMap(Object json, String root, boolean isNew) {if (json instanceof JSONObject) {JSONObject jsonObject = ((JSONObject) json);Iterator iterator = jsonObject.keySet().iterator();while (iterator.hasNext()) {Object key = iterator.next();Object value = jsonObject.get(key);String newRoot = "".equals(root) ? key + "" : root + "." + key;fillInResultMap(value, newRoot, isNew);}} else if (json instanceof JSONArray) {JSONArray jsonArray = (JSONArray) json;//将jsonArray进行排序if (isSort) {//需要排序String sortEntityName = root.substring(root.lastIndexOf(".") + 1);//需要排序 获取排序字段String sortFiledName = filedNameMap.get(sortEntityName);if (!StringUtils.isEmpty(sortFiledName)) {jsonArray = JsonAndMapSortUtils.jsonArrayToSort(jsonArray, sortFiledName, true);}}final JSONArray jsonArray1 = jsonArray;Stream.iterate(0, integer -> integer + 1).limit(jsonArray1.size()).forEach(index -> {Object value = jsonArray1.get(index);String newRoot = "".equals(root) ? "[" + index + "]" : root + ".[" + index + "]";fillInResultMap(value, newRoot, isNew);});}}/*** 封装json转map后的数据** @param value* @param newRoot* @param isNew 区别新旧json*/public void fillInResultMap(Object value, String newRoot, boolean isNew) {if (value instanceof JSONObject || value instanceof JSONArray) {convertJsonToMap(value, newRoot, isNew);} else {//设置跳过比对的字段，直接不装入mapboolean check = ArrayUtils.contains(JsonCompareUtils.skipCompareFiledNameMap, newRoot);if (!check){if (!isNew) {oldJsonToMap.put(newRoot, value);} else {newJsonToMap.put(newRoot, value);}}}}/*** 比较两个map，将不同的数据以map形式存储并返回** @param oldJsonMap* @param newJsonMap* @return*/private Map<String, Object> compareTwoMaps(Map<String, Object> oldJsonMap, Map<String, Object> newJsonMap) {//1.将newJsonMap的不同数据装进oldJsonMap，同时删除oldJsonMap中与newJsonMap相同的数据newJsonMap.forEach((k, v) -> {Map<String, Object> differenceMap = new HashMap<>();if (oldJsonMap.containsKey(k)) {Object oldValue = oldJsonMap.get(k);if (v.equals(oldValue)) {oldJsonMap.remove(k);} else {differenceMap.put("oldValue", oldValue);differenceMap.put("newValue", v);oldJsonMap.put(k, differenceMap);}} else {differenceMap.put("oldValue", "no exists " + k);differenceMap.put("newValue", v);oldJsonMap.put(k, differenceMap);}});//2.统一oldJsonMap中newMap不存在的数据的数据结构，便于解析oldJsonMap.forEach((k, v) -> {if (!(v instanceof Map)) {Map<String, Object> differenceMap = new HashMap<>();differenceMap.put("oldValue", v);differenceMap.put("newValue", "no exists " + k);oldJsonMap.put(k, differenceMap);}});return oldJsonMap;}/*** 将已经找出不同数据的map根据key的层级结构封装成json返回** @param map* @return*/private String convertMapToJson(Map<String, Object> map) {JSONObject resultJSONObject = new JSONObject();for (Iterator<Map.Entry<String, Object>> it = map.entrySet().iterator(); it.hasNext(); ) {Map.Entry<String, Object> item = it.next();String key = item.getKey();Object value = item.getValue();String[] paths = key.split("\\.");int i = 0;//用於深度標識對象Object remarkObject = null;int indexAll = paths.length - 1;while (i <= paths.length - 1) {String path = paths[i];if (i == 0) {//初始化对象标识if (resultJSONObject.containsKey(path)) {remarkObject = resultJSONObject.get(path);} else {if (indexAll > i) {if (paths[i + 1].matches("\\[[0-9]+\\]")) {remarkObject = new JSONArray();} else {remarkObject = new JSONObject();}resultJSONObject.put(path, remarkObject);} else {resultJSONObject.put(path, value);}}i++;continue;}//匹配集合对象if (path.matches("\\[[0-9]+\\]")) {int startIndex = path.lastIndexOf("[");int endIndext = path.lastIndexOf("]");int index = Integer.parseInt(path.substring(startIndex + 1, endIndext));if (indexAll > i) {if (paths[i + 1].matches("\\[[0-9]+\\]")) {while (((JSONArray) remarkObject).size() <= index) {if (((JSONArray) remarkObject).size() == index) {((JSONArray) remarkObject).add(index, new JSONArray());} else {((JSONArray) remarkObject).add(null);}}} else {while (((JSONArray) remarkObject).size() <= index) {if (((JSONArray) remarkObject).size() == index) {((JSONArray) remarkObject).add(index, new JSONObject());} else {((JSONArray) remarkObject).add(null);}}}remarkObject = ((JSONArray) remarkObject).get(index);} else {while (((JSONArray) remarkObject).size() <= index) {if (((JSONArray) remarkObject).size() == index) {((JSONArray) remarkObject).add(index, value);} else {((JSONArray) remarkObject).add(null);}}}} else {if (indexAll > i) {if (paths[i + 1].matches("\\[[0-9]+\\]")) {if (!((JSONObject) remarkObject).containsKey(path)) {((JSONObject) remarkObject).put(path, new JSONArray());}} else {if (!((JSONObject) remarkObject).containsKey(path)) {((JSONObject) remarkObject).put(path, new JSONObject());}}remarkObject = ((JSONObject) remarkObject).get(path);} else {((JSONObject) remarkObject).put(path, value);}}i++;}}return JSON.toJSONString(resultJSONObject);}public boolean isSort() {return isSort;}public void setSort(boolean sort) {isSort = sort;}public static void main(String[] args) {String oldStr = "{\"abilityLevel\":\"2020101240000000000002\",\"activityId\":\"202208301413310000412\",\"addLibTime\":1662083360000,\"ansKnowModelIds\":\"1#201812051814150000475\",\"answer\":\"AB\",\"ascriptionItemLib\":\"0\",\"attributeList\":[{\"content\":\"<p>A</p>\",\"id\":\"202209020949170005783\",\"itemId\":\"202209020949150001521\",\"knowModelRelId\":\"201812051814150000475\",\"name\":\"A\",\"sort\":1,\"type\":\"option\"},{\"content\":\"<p style=\\\"font-family:'Times New Roman','宋体';font-size:12pt;padding:0;margin:0;\\\">B</p>\",\"id\":\"202209020949170005784\",\"itemId\":\"202209020949150001521\",\"name\":\"B\",\"sort\":2,\"type\":\"option\"},{\"content\":\"<p style=\\\"font-family:'Times New Roman','宋体';font-size:12pt;padding:0;margin:0;\\\">C</p>\",\"id\":\"202209020949170005785\",\"itemId\":\"202209020949150001521\",\"name\":\"C\",\"sort\":3,\"type\":\"option\"},{\"content\":\"<p style=\\\"font-family:'Times New Roman','宋体';font-size:12pt;padding:0;margin:0;\\\">D</p>\",\"id\":\"202209020949170005786\",\"itemId\":\"202209020949150001521\",\"name\":\"D\",\"sort\":4,\"type\":\"option\"},{\"content\":\"11\",\"createTime\":1662083368000,\"createTimeString\":\"2022-09-02 09:49:28\",\"creater\":\"10001\",\"id\":\"202209020949170005787\",\"itemId\":\"202209020949150001521\",\"name\":\"大纲依据\",\"searchFlag\":\"1\",\"sort\":1,\"subItemTypeAttrId\":\"100041\",\"type\":\"expandAttr\"},{\"content\":\"11\",\"createTime\":1662083370000,\"createTimeString\":\"2022-09-02 09:49:30\",\"creater\":\"10001\",\"id\":\"202209020949280005788\",\"itemId\":\"202209020949150001521\",\"name\":\"教材依据\",\"searchFlag\":\"1\",\"sort\":2,\"subItemTypeAttrId\":\"100042\",\"type\":\"expandAttr\"},{\"content\":\"11\",\"createTime\":1662083371000,\"createTimeString\":\"2022-09-02 09:49:31\",\"creater\":\"10001\",\"id\":\"202209020949290005789\",\"itemId\":\"202209020949150001521\",\"name\":\"关键字\",\"searchFlag\":\"1\",\"sort\":3,\"subItemTypeAttrId\":\"100043\",\"type\":\"expandAttr\"}],\"auditCount\":0,\"auditStatus\":0,\"childItemList\":[],\"createTime\":1662083350000,\"createTimeString\":\"2022-09-02 09:49:10\",\"creater\":\"10001\",\"delFlag\":\"0\",\"difficult\":\"3\",\"id\":\"202209020949150001521\",\"isComposite\":0,\"isTopVersion\":0,\"itemCode\":\"KJCJ202209020949140001501\",\"itemContent\":\"<p style=\\\"font-family:'Times New Roman','宋体';font-size:12pt;padding:0;margin:0;\\\">2.<span style=\\\"color: #333333; font-family: Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "WenQuanYi Micro Hei", sans-serif; font-size: 14px; text-align: justify; background-color: #FFFFFF;\\\">按照并购双方行业相关性划分，判断并购类型（横向并购or混合并购）</span></p>\",\"itemKnowledgeList\":[{\"id\":\"202209020949300001537\",\"itemId\":\"202209020949150001521\",\"knowledgeId\":\"1240004\",\"knowledgeStr\":\"2020年经济法基础/第一章总论/第一节法律基础/一、法和法律/（一）法和法律的概念\",\"level\":\"1\",\"pid\":\"202209020946580001519\"}],\"itemLevel\":1,\"itemSource\":\"202208301413310000412\",\"itemTypeId\":\"4\",\"itemVersion\":\"1\",\"keyWord\":\"\",\"knowledgeId\":\"1240004\",\"knowledgeStr\":\"2020年经济法基础/第一章总论/第一节法律基础/一、法和法律/（一）法和法律的概念\",\"knowledgeSyllabusName\":\"2020年经济法基础\",\"lockStatus\":1,\"modifyChlidItems\":[],\"paperCount\":0,\"paperItemRelation\":{},\"paperStructure\":{},\"parentId\":\"202209020946580001519\",\"processedItemContent\":\"<p style=\\\"font-family:'Times New Roman','宋体';font-size:12pt;padding:0;margin:0;\\\">2.<span style=\\\"color: #333333; font-family: Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "WenQuanYi Micro Hei", sans-serif; font-size: 14px; text-align: justify; background-color: #FFFFFF;\\\">按照并购双方行业相关性划分，判断并购类型（横向并购or混合并购）</span></p>\",\"score\":2,\"sort\":2,\"sourceType\":\"2\",\"structId\":\"\",\"subItemTypeId\":\"20180228155501000004\",\"subjectId\":\"4\",\"updateTime\":1662083350000,\"updateTimeString\":\"2022-09-02 09:49:10\",\"updater\":\"10001\"}";String newStr = "{\"abilityLevel\":\"2020101240000000000002\",\"activityId\":\"202208301413310000412\",\"addLibTime\":1662083360000,\"analysis\":\"\",\"ansKnowModelIds\":\"1#201812051814150000475\",\"answer\":\"AB\",\"ascriptionItemLib\":\"0\",\"attributeList\":[{\"content\":\"<p>A</p>\",\"id\":\"202209021135210005855\",\"itemId\":\"202209020949150001521\",\"knowModelRelId\":\"201812051814150000475\",\"name\":\"A\",\"sort\":1,\"type\":\"option\"},{\"content\":\"<p style=\\\"font-family:'Times New Roman','宋体';font-size:12pt;padding:0;margin:0;\\\">B</p>\",\"id\":\"202209021135210005856\",\"itemId\":\"202209020949150001521\",\"name\":\"B\",\"sort\":2,\"type\":\"option\"},{\"content\":\"<p style=\\\"font-family:'Times New Roman','宋体';font-size:12pt;padding:0;margin:0;\\\">C</p>\",\"id\":\"202209021135210005857\",\"itemId\":\"202209020949150001521\",\"name\":\"C\",\"sort\":3,\"type\":\"option\"},{\"content\":\"<p style=\\\"font-family:'Times New Roman','宋体';font-size:12pt;padding:0;margin:0;\\\">D</p>\",\"id\":\"202209021135210005858\",\"itemId\":\"202209020949150001521\",\"name\":\"D\",\"sort\":4,\"type\":\"option\"},{\"content\":\"11\",\"createTime\":1662089721000,\"createTimeString\":\"2022-09-02 11:35:21\",\"creater\":\"10001\",\"id\":\"202209021135210005859\",\"itemId\":\"202209020949150001521\",\"name\":\"大纲依据\",\"searchFlag\":\"1\",\"sort\":1,\"subItemTypeAttrId\":\"100041\",\"type\":\"expandAttr\"},{\"content\":\"11\",\"createTime\":1662089721000,\"createTimeString\":\"2022-09-02 11:35:21\",\"creater\":\"10001\",\"id\":\"202209021135210005860\",\"itemId\":\"202209020949150001521\",\"name\":\"教材依据\",\"searchFlag\":\"1\",\"sort\":2,\"subItemTypeAttrId\":\"100042\",\"type\":\"expandAttr\"},{\"content\":\"11\",\"createTime\":1662089722000,\"createTimeString\":\"2022-09-02 11:35:22\",\"creater\":\"10001\",\"id\":\"202209021135210005861\",\"itemId\":\"202209020949150001521\",\"name\":\"关键字\",\"searchFlag\":\"1\",\"sort\":3,\"subItemTypeAttrId\":\"100043\",\"type\":\"expandAttr\"}],\"auditCount\":0,\"auditStatus\":0,\"childItemList\":[],\"createTime\":1662083350000,\"createTimeString\":\"2022-09-02 09:49:10\",\"creater\":\"10001\",\"delFlag\":\"0\",\"difficult\":\"5\",\"id\":\"202209020949150001521\",\"isComposite\":0,\"isTopVersion\":0,\"itemCode\":\"KJCJ202209020949140001501\",\"itemContent\":\"<p style=\\\"font-family:'Times New Roman','宋体';font-size:12pt;padding:0;margin:0;\\\">2.<span style=\\\"color: #333333; font-family: Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "WenQuanYi Micro Hei", sans-serif; font-size: 14px; text-align: justify; background-color: #FFFFFF;\\\">按照并购双方行业相关性划分，判断并购类型（横向并购or混合并购）</span></p>\",\"itemKnowledgeList\":[{\"id\":\"202209021135230001557\",\"itemId\":\"202209020949150001521\",\"knowledgeId\":\"1240004\",\"knowledgeStr\":\"2020年经济法基础/第一章总论/第一节法律基础/一、法和法律/（一）法和法律的概念\",\"level\":\"1\",\"pid\":\"202209020946580001519\"}],\"itemLevel\":1,\"itemSource\":\"202208301413310000412\",\"itemTypeId\":\"4\",\"itemVersion\":\"2\",\"keyWord\":\"\",\"knowledgeId\":\"1240004\",\"knowledgeStr\":\"2020年经济法基础/第一章总论/第一节法律基础/一、法和法律/（一）法和法律的概念\",\"knowledgeSyllabusName\":\"2020年经济法基础\",\"lockStatus\":1,\"modifyChlidItems\":[],\"paperCount\":0,\"paperItemRelation\":{},\"paperStructure\":{},\"parentId\":\"202209020946580001519\",\"processedItemContent\":\"<p style=\\\"font-family:'Times New Roman','宋体';font-size:12pt;padding:0;margin:0;\\\">2.<span style=\\\"color: #333333; font-family: Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "WenQuanYi Micro Hei", sans-serif; font-size: 14px; text-align: justify; background-color: #FFFFFF;\\\">按照并购双方行业相关性划分，判断并购类型（横向并购or混合并购）</span></p>\",\"score\":2,\"sort\":2,\"sourceType\":\"2\",\"structId\":\"\",\"subItemTypeId\":\"20180228155501000004\",\"subjectId\":\"4\",\"updateTime\":1662089720000,\"updateTimeString\":\"2022-09-02 11:35:20\",\"updater\":\"10001\"}";System.out.println(new JsonCompareUtils().compare2Json(oldStr, newStr));System.out.println("\n========测试复杂json的比对============");}
}JsonAndMapSortUtils 用于jsonArray排序
import com.alibaba.fastjson.JSONArray;
import com.alibaba.fastjson.JSONObject;
import sun.misc.ASCIICaseInsensitiveComparator;import java.util.*;public class JsonAndMapSortUtils {/*** map排序* @param map* @param keySort* @param <k>* @param <v>* @return*/public static <k,v> List mapByKeyToSort(Map<k,v> map , final Comparator keySort){List<Map.Entry<k,v>> entryList = new ArrayList<>(map.entrySet());Collections.sort(entryList, (o1, o2) -> keySort.compare(o1.getKey(),o2.getKey()));System.out.println("排序=====");entryList.forEach(m->{System.out.println(m.getKey()+"===>"+m.getValue());});return entryList;}/*** JSONArray排序* @param jsonArray* @param fildName* @param isAsc* @return*/public static JSONArray jsonArrayToSort(JSONArray jsonArray,final String fildName,final boolean isAsc){JSONArray afterSortJsonArray = new JSONArray();List<JSONObject> objectList = new ArrayList<>();jsonArray.forEach(obj ->{objectList.add((JSONObject)obj);});Collections.sort(objectList, (o1, o2) -> {String fildValueA = o1.getString(fildName);String fildValueB = o2.getString(fildName);if (isAsc){return fildValueA.compareTo(fildValueB);}return fildValueB.compareTo(fildValueA);});objectList.forEach(obj->{afterSortJsonArray.add(obj);});return afterSortJsonArray;}/***准备map测试数据*/public static Map<String,String> getMapData(){LinkedHashMap<String,String> map = new LinkedHashMap<>();map.put("key1","测试1");map.put("key3","测试3");map.put("key5","测试5");map.put("key2","测试2");map.put("key4","测试4");return map;}/***准备json测试数据*/public static JSONArray getJsonArrayData(){JSONArray jsonArray = new JSONArray();JSONObject jsonObject1 = new JSONObject();jsonObject1.put("userId","1001");jsonObject1.put("name","测试1");jsonArray.add(jsonObject1);JSONObject jsonObject3 = new JSONObject();jsonObject3.put("userId","1003");jsonObject3.put("name","测试3");jsonArray.add(jsonObject3);JSONObject jsonObject2 = new JSONObject();jsonObject2.put("userId","1002");jsonObject2.put("name","测试2");jsonArray.add(jsonObject2);return jsonArray;}public static void main(String[] args) {Map<String,String> map = JsonAndMapSortUtils.getMapData();JSONArray jsonArray = JsonAndMapSortUtils.getJsonArrayData();List afterSortMap = JsonAndMapSortUtils.mapByKeyToSort(map,new ASCIICaseInsensitiveComparator());JSONArray afterSortJsonArray_isAsc = JsonAndMapSortUtils.jsonArrayToSort(jsonArray,"userId",true);JSONArray afterSortJsonArray_noAsc = JsonAndMapSortUtils.jsonArrayToSort(jsonArray,"userId",false);System.out.println("map排序前："+map);System.out.println("map排序后："+afterSortMap+"\n");System.out.println("JsonArray排序前："+jsonArray);System.out.println("JsonArray排序后==》升序："+afterSortJsonArray_isAsc);System.out.println("JsonArray排序后==》降序："+afterSortJsonArray_noAsc);}}
源码走读
整个源码调用链路如下图，简单来说过程就是：object拆分解析-新旧数据逐个对比-结果信息组装三个步骤
