版权声明：有不足之处欢迎指出，欢迎交流 https://blog.csdn.net/qq_33594101/article/details/91792167
思路:将对象里面的每个属性转为path:value模式用map装起来,然后根据path比较值，返回不同(这里需要注意的是，如果是集合，必须是有序的且按照规则排好序的)
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));
}
}
运行结果
{“a”:{“newValue”:“aa”,“oldValue”:“aaa”},“b”:{“newValue”:“bb”,“oldValue”:“bbb”}}