Check if one list contains element from the other

I have two lists with different objects in them.

List<Object1> list1;
List<Object2> list2;

I want to check if element from list1 exists in list2, based on specific attribute (Object1 and Object2 have (among others), one mutual attribute (with type Long), named attributeSame).

right now, I do it like this:

boolean found = false;
for(Object1 object1 : list1){
   for(Object2 object2: list2){
       if(object1.getAttributeSame() == object2.getAttributeSame()){
           found = true;
           //also do something
       }
    }
    if(!found){
        //do something
    }
    found = false;
}

But I think there is a better and faster way to do this :) Can someone propose it?

Thanks!

If you just need to test basic equality, this can be done with the basic JDK without modifying the input lists in the one line

!Collections.disjoint(list1, list2);

If you need to test a specific property, that's harder. I would recommend, by default,

list1.stream()
   .map(Object1::getProperty)
   .anyMatch(
     list2.stream()
       .map(Object2::getProperty)
       .collect(toSet())
       ::contains)

...which collects the distinct values in list2 and tests each value in list1 for presence.

To shorten Narendra's logic, you can use this:

boolean var = lis1.stream().anyMatch(element -> list2.contains(element));

You can use Apache Commons CollectionUtils:

if(CollectionUtils.containsAny(list1,list2)) {  
    // do whatever you want
} else { 
    // do other thing 
}  

This assumes that you have properly overloaded the equals functionality for your custom objects.

There is one method of Collection named retainAll but having some side effects for you reference

Retains only the elements in this list that are contained in the specified collection (optional operation). In other words, removes from this list all of its elements that are not contained in the specified collection.

true if this list changed as a result of the call

Its like

boolean b = list1.retainAll(list2);