I am trying to compare 2 JSON files, they have arrays with duplicated values.
My first JSON Object has an array like this:
"categories": [
"May",
"Apr",
"Mar"
]
My second JSON object has an array like this:
"categories": [
"May",
"May",
"Apr",
"Apr",
"Mar",
"Mar"
]
I am comparing the JSON using flat maps that can be found in this link comparing JSONs using guava
Here is part of my code:
private String smartJSONsCompare(JSONObject leftJson, JSONObject rightJson) {
String result = "</br>";
Gson gson = new Gson();
Type type = new TypeToken<Map<String, Object>>(){}.getType();
Map<String, Object> leftMap = gson.fromJson(leftJson.toString(), type);
Map<String, Object> rightMap = gson.fromJson(rightJson.toString(), type);
Map<String, Object> leftFlatMap = FlatMapUtil.flatten(leftMap);
Map<String, Object> rightFlatMap = FlatMapUtil.flatten(rightMap);
MapDifference<String, Object> difference = Maps.difference(leftFlatMap, rightFlatMap);
StringBuilder SB = new StringBuilder("</br>");
SB.append("Entries only on LEFT: </br>");
difference.entriesOnlyOnLeft().forEach((key, value) -> SB.append(key + ": " + value + "</br>"));
SB.append("Entries only on RIGHT: </br>");
difference.entriesOnlyOnRight().forEach((key, value) -> SB.append(key + ": " + value + "</br>"));
SB.append("Entries full difference : </br>");
difference.entriesDiffering().forEach((key, value) -> SB.append(key + ": " + value + "</br>"));
result = SB.toString();
return result;
}
I wish to be able to present the difference in a more "smart" way. In other words: showing all the objects / arrays in the JONSs that don't match. What is missing or what was added to the compared JSON.
For the "categories" array my code returns a message that their is a mismatch, but doesn't state the difference in an elegant way.
What can I do?
I have change a bit in your solution to get the wanted result.
I would do my difference check in List, therefore I will create method to change JSON to list of strings based on your code:
private static List<String> jsonToList(String json){
List<String> list = new ArrayList<>();
Gson gson = new Gson();
Type type = new TypeToken<Map<String, Object>>(){}.getType();
Map<String, Object> jsonMap = gson.fromJson(json, type);
Map<String, Object> flatten = FlatMapUtil.flatten(jsonMap);
flatten.forEach((k, v) -> list.add(v.toString()));
return list;
}
Update
When I answered the question I did things a bit fast, the jsonToList was based on your code. As it is right now it is over complicated to what you are asking for. I have therefore made much lighter version using the following method in stead:
private static List<String> jsonToList(String json) {
JSONObject response = new JSONObject(json);
List<String> list = new ArrayList<>();
JSONArray jsonArray = response.getJSONArray("categories");
if (jsonArray != null) {
for (int i = 0; i < jsonArray.length(); i++) {
list.add(jsonArray.get(i).toString());
}
}
return list;
}
That said, now you have two choices and it is up to you to find out which one fits best to your needs and take it from here.
End of Update
for this example I have made 3 test examples
String main = "{\"categories\":[\"May\",\"Apr\",\"Mar\"]}";
String json1 = "{\"categories\":[\"May\",\"May\",\"Apr\",\"Apr\",\"Mar\",\"Mar\"]}";
String json2 = "{\"categories\":[\"May\",\"Apr\",\"Apr\",\"Mar\",\"Mar\",\"Mar\"]}";
String json3 = "{\"categories\":[\"May\",\"Apr\",\"Mar\",\"Mar\"]}";
in my second step I will create a
List<String> mainList = jsonToList(main);
List<String> list1 = jsonToList(json1);
so far so good. Now I make a method to take the extra difference of the 2 list, that mean as you requested in your comments, we take only all values that are duplicated more than once and return them in list. In this method I used hashmap only count duplicates and than take the all that is repeated more than 1 time:
private static List<String> diffList(List<String> mainList, List<String> secondList){
List<String> list = new ArrayList<String>();
Map<String, Integer> wordCount = new HashMap<>();
for(String word: secondList) {
if(mainList.contains(word)) {
Integer count = wordCount.get(word);
wordCount.put(word, (count == null) ? 1 : count + 1);
if(wordCount.get(word) > 1){
list.add(word);
}
}
}
return list;
}
Finally I would test all cases, for instance for list1:
List<String> diff1 = diffList(mainList, list1);
for (String s : diff1) {
System.out.println(s);
}
The output will be
May
Apr
Mar
for list2
Apr
Mar
Mar
And for list3
Mar
Now I will separate view method from the your method and create some thing like, just to make my code more clear and easy to work with:
private static String viewResult(List<String> list1, List<String> list2, List<String> duplicate){
String result;
StringBuilder SB = new StringBuilder("</br>");
SB.append("Entries only on LEFT: </br>");
list1.forEach(e -> SB.append(e + "</br>"));
SB.append("Entries only on RIGHT: </br>");
list2.forEach(e -> SB.append(e + "</br>"));
SB.append("Entries full difference : </br>");
duplicate.forEach(e -> SB.append(e + "</br>"));
result = SB.toString();
return result;
}
So if we put all this code together I will be some thing like this, and the following code is to demonstrate how things works, but from here you can take it to the next level in your code:
public static void main(String[] args) {
String main = "{\"categories\":[\"May\",\"Apr\",\"Mar\"]}";
String json1 = "{\"categories\":[\"May\",\"May\",\"Apr\",\"Apr\",\"Mar\",\"Mar\"]}";
String json2 = "{\"categories\":[\"May\",\"Apr\",\"Apr\",\"Mar\",\"Mar\",\"Mar\"]}";
String json3 = "{\"categories\":[\"May\",\"Apr\",\"Mar\",\"Mar\"]}";
List<String> mainList = jsonToList(main);
List<String> list1 = jsonToList(json1);
List<String> diff1 = diffList(mainList, list1);
for (String s : diff1) {
System.out.println(s);
}
String view = viewResult(mainList, list1, diff1);
}
private static List<String> jsonToList(String json){
List<String> list = new ArrayList<String>();
Gson gson = new Gson();
Type type = new TypeToken<Map<String, Object>>(){}.getType();
Map<String, Object> jsonMap = gson.fromJson(json, type);
Map<String, Object> flatten = FlatMapUtil.flatten(jsonMap);
flatten.forEach((k, v) -> list.add(v.toString()));
return list;
}
private static List<String> diffList(List<String> mainList, List<String> secondList){
List<String> list = new ArrayList<String>();
Map<String, Integer> wordCount = new HashMap<>();
for(String word: secondList) {
if(mainList.contains(word)) {
Integer count = wordCount.get(word);
wordCount.put(word, (count == null) ? 1 : count + 1);
if(wordCount.get(word) > 1){
list.add(word);
}
}
}
return list;
}
private static String viewResult(List<String> list1, List<String> list2, List<String> duplicate){
String result;
StringBuilder SB = new StringBuilder("</br>");
SB.append("Entries only on LEFT: </br>");
list1.forEach(e -> SB.append(e + "</br>"));
SB.append("Entries only on RIGHT: </br>");
list2.forEach(e -> SB.append(e + "</br>"));
SB.append("Entries full difference : </br>");
duplicate.forEach(e -> SB.append(e + "</br>"));
result = SB.toString();
return result;
}