Java remove "parent":"somevalue" from flattened json if “parent”:“somevalue” and there also exists a “parent.new”: “somevalue” in same json

Question

I Have json like this :

{
"lastModifiedBy" :"value",
"lastModifiedBy.$oid": "1234567189",
"displayedBy" : 0,
"displayedBy.one" : "Abhi",
"displayedBy.one.new" : "Sammy",
"displayedBy.two":"random_value3",
"a.b":null,
"b.c":null,
"d.e.f":null
}

I only want to keep the longest keys and not the previous state parent without affecting the other keys output I need:

{
"lastModifiedBy.$oid": "1234567189",
"displayedBy.one.new" : "Sammy",
"displayedBy.two":"random_value3",
"a.b":null,
"b.c":null,
"d.e.f":null
}

Is there a way to do this in Jackson or any other java package.?

Answer 1

Try this.

    Map<String, String> map = new HashMap<>();
    map.put("lastModifiedBy", "value");
    map.put("lastModifiedBy.$oid", "1234567189");
    map.put("displayedBy", "0");
    map.put("displayedBy.one", "Abhi");
    map.put("displayedBy.one.new", "Sammy");
    map.put("displayedBy.two", "random_value3");
    map.put("a.b", null);
    map.put("b.c", null);
    map.put("d.e.f", null);
    List<String> removes = new ArrayList<>();
    for (String parent : map.keySet())
        for (String child : map.keySet())
            if (parent != child && child.startsWith(parent)) {
                removes.add(parent);
                break;
            }
    for (String key : removes)
        map.remove(key);
    System.out.println(map);

output:

{a.b=null, d.e.f=null, displayedBy.one.new=Sammy, b.c=null, displayedBy.two=random_value3, lastModifiedBy.$oid=1234567189}

Answer 2

If you are able to convert it into an ArrayList, remove all keys you dont need. For example with foreach.

If you are able to convert it into an String split at ":" and "," remove the "s create an ArrayList and populate it by using index 0,2,4... as key and 1,3,5... as value and do the thing mentioned above.