Need to eliminate the duplicate schema from two different list

Question

Lets consider I have two lists

List1:

[{
“problem”: “prb1",
“status”: “ACTIVE”,
“createTs”: “somedate-1"
}]

List 2:

[{
“problem”: “prb1",
“status”: “ACTIVE”,
“date”: “somedate-1"
},
{
“problem”: “prb1",
“status”: “ACTIVE”,
“date”: “somedate-2"
}]

I want to see if there is an ACTIVE problem in the list2 that doesn't exist as ACTIVE in the list1.

I tried below which is not covering duplicate entry(above scenario)

   list2.removeAll(list1);
             activeprob =
            list2
            .stream()
            .filter(Objects::nonNull)
            .filter(list -> list.getStatus().equals("ACTIVE"))
            .collect(Collectors.toList());

In other way I want to eliminate the duplicate entry in list2 comparing with list1 based on status and date. having same problem is not a concern but should be unique in terms of date.

Please share your insights

Answer 1

What I would suggest doing is

1. Define hashCode and equals methods for the Problem class (most IDEs can auto generate these methods) if you only want to use the date for equality do that
2. Convert the List to a Set for improved efficiency, and use the HashSet.contains method
3. Use a for loop to iterate over the Set. This will allow you to debug the code easier as it is more verbose and you can put a breakpoint in the for loop to see more clearly each step

An example for loop could be

for(Problem p:list2){
   if(list1.contains(p)&&p.status==ACTIVE){
       list2.remove(p);
   }
}

Then list2 should have all duplicates that are ACTIVE removed

Answer 2

can you try this, this is going to remove if the active record in list2 is not not active in list1 and same problem name and date. I hope it helps.

list2.removeIf(obj -> {
        List filteredList1 = list1.stream()
                .filter(ob -> obj.getProblem().equals(ob.getProblem())
                        && (!"ACTIVE".equals(ob.getStatus()) && "ACTIVE".equals(obj.getStatus()) )
                        && ob.getDate().equals(obj.getDate()) )
                .collect(Collectors.toList());
        return filteredList1.isEmpty();
    } );

IGNORE from here:
I hope you have almost done, except the small change. I am adding a condition to the filter.

activeprob = list2 .stream() .filter(Objects::nonNull) .filter(list -> list.getStatus().equals("ACTIVE") && notActivelyAvailable(list, list1)) .collect(Collectors.toList());

create a method like this or else you can have this filtered list readily available and can use it directly instead of calling notActivelyAvailable method.

public boolean notActivelyAvailable(YourClass obj, List<YourClass> list1) {
   List<YourClass> filteredList1 = list.stream().filter(yourObj -> "Active".equals(yourObj.getStatus()).collect(Collectors.toList());
if ( filteredList1.contains(obj)) return false;
else return true;
}