Copyright: inadequate welcome that, please share https://blog.csdn.net/qq_33594101/article/details/91792167
Thinking: each attribute of an object into the inside path: Mode value loaded up with the map, and then the comparison value according to the path, and returns (It should be noted that, if it is set, must be ordered and sorted according to the rules of)
pom.xml
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>fastjson</artifactId>
<version>1.2.51</version>
</dependency>
CampareJson.java
package com.watertour.service;
import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONArray;
import com.alibaba.fastjson.JSONObject;
import java.util.HashMap;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.Map;
public class CampareJson {
public String campareJsonObject(String oldJsonStr, String newJsonStr1) {
//将字符串转换为json对象
JSON oldJson = JSON.parseObject(oldJsonStr);
JSON newJson = JSON.parseObject(newJsonStr1);
//递归遍历json对象所有的key-value，将其封装成path:value格式进行比较
Map<String, Object> oldMap = new LinkedHashMap<>();
Map<String, Object> newMap = new LinkedHashMap<>();
convertJsonToMap(oldJson, "", oldMap);
convertJsonToMap(newJson, "", newMap);
Map<String, Object> differenceMap = campareMap(oldMap, newMap);
//将最终的比较结果把不相同的转换为json对象返回
String jsonObject = convertMapToJson(differenceMap);
return jsonObject;
}
/**
* 将json数据转换为map存储用于比较
*
* @param json
* @param root
* @param resultMap
*/
private void convertJsonToMap(Object json, String root, Map<String, Object> resultMap) {
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;
if (value instanceof JSONObject || value instanceof JSONArray) {
convertJsonToMap(value, newRoot, resultMap);
} else {
resultMap.put(newRoot, value);
}
}
} else if (json instanceof JSONArray) {
JSONArray jsonArray = (JSONArray) json;
for (int i = 0; i < jsonArray.size(); i++) {
Object vaule = jsonArray.get(i);
String newRoot = "".equals(root) ? "[" + i + "]" : root + ".[" + i + "]";
if (vaule instanceof JSONObject || vaule instanceof JSONArray) {
convertJsonToMap(vaule, newRoot, resultMap);
} else {
resultMap.put(newRoot, vaule);
}
}
}
}
/**
* 比较两个map，返回不同数据
*
* @param oldMap
* @param newMap
* @return
*/
private Map<String, Object> campareMap(Map<String, Object> oldMap, Map<String, Object> newMap) {
//遍历newMap，将newMap的不同数据装进oldMap，同时删除oldMap中与newMap相同的数据
campareNewToOld(oldMap, newMap);
//將舊的有新的沒有的數據封裝數據結構存在舊的裡面
campareOldToNew(oldMap);
return oldMap;
}
/**
* 將舊的有新的沒有的數據封裝數據結構存在舊的裡面
* @param oldMap
* @return
*/
private void campareOldToNew(Map<String, Object> oldMap) {
//统一oldMap中newMap不存在的数据的数据结构，便于解析
for (Iterator<Map.Entry<String, Object>> it = oldMap.entrySet().iterator(); it.hasNext(); ) {
Map.Entry<String, Object> item = it.next();
String key = item.getKey();
Object value = item.getValue();
int lastIndex = key.lastIndexOf(".");
if (!(value instanceof Map)) {
Map<String, Object> differenceMap = new HashMap<>();
differenceMap.put("oldValue", value);
differenceMap.put("newValue", "");
oldMap.put(key, differenceMap);
}
}
}
/**
* 將新的map與舊的比較，並將數據統一存在舊的裡面
* @param oldMap
* @param newMap
*/
private void campareNewToOld(Map<String, Object> oldMap, Map<String, Object> newMap) {
for (Iterator<Map.Entry<String, Object>> it = newMap.entrySet().iterator(); it.hasNext(); ) {
Map.Entry<String, Object> item = it.next();
String key = item.getKey();
Object newValue = item.getValue();
Map<String, Object> differenceMap = new HashMap<>();
int lastIndex = key.lastIndexOf(".");
String lastPath = key.substring(lastIndex + 1).toLowerCase();
if (oldMap.containsKey(key)) {
Object oldValue = oldMap.get(key);
if (newValue.equals(oldValue)) {
oldMap.remove(key);
continue;
} else {
differenceMap.put("oldValue", oldValue);
differenceMap.put("newValue", newValue);
oldMap.put(key, differenceMap);
}
} else {
differenceMap.put("oldValue", "");
differenceMap.put("newValue", newValue);
oldMap.put(key, differenceMap);
}
}
}
/**
* 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;
Object remarkObject = null;//用於深度標識對象
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;
}
if (path.matches("\\[[0-9]+\\]")) {//匹配集合对象
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]+\\]")) {
((JSONObject) remarkObject).put(path, new JSONArray());
} else {
((JSONObject) remarkObject).put(path, new JSONObject());
}
remarkObject = ((JSONObject) remarkObject).get(path);
} else {
((JSONObject) remarkObject).put(path, value);
}
}
i++;
}
}
return JSON.toJSONString(resultJSONObject);
}
public static void main(String[] args){
String oldStr= "{a:'aaa',b:'bbb'}";
String newStr= "{a:'aa',b:'bb'}";
System.out.println(new CampareJson().campareJsonObject(oldStr,newStr));
}
}
operation result
{“a”:{“newValue”:“aa”,“oldValue”:“aaa”},“b”:{“newValue”:“bb”,“oldValue”:“bbb”}}