Finding the different elements between two ArrayLists in Java

Question

How can I know the different element between 2 array list in java? I need the exact element not a Boolean value which can be retrieved using removeAll().

Answer 1

If I understood your question correctly then following method nonOverLap in the code below should get you that:

 Collection union(Collection coll1, Collection coll2) {
    Set union = new HashSet<>(coll1);
    union.addAll(new HashSet<>(coll2));
    return union;
}

 Collection intersect(Collection coll1, Collection coll2) {
    Set intersection = new HashSet<>(coll1);
    intersection.retainAll(new HashSet<>(coll2));
    return intersection;
}

 Collection nonOverLap(Collection coll1, Collection coll2) {
    Collection result = union(coll1, coll2);
    result.removeAll(intersect(coll1, coll2));
    return result;
}