An elegant way to find diff of two list of objects in Java
I would create this method:

private MyObject findMatch(List&lt;MyObject&gt; objsFromDB, MyObjRequest req_obj){
    for(MyObject db_obj : objsFromDB){
        if(isSameObj(db_obj, req_obj)){
            return db_obj;
        }
    }
    return null;
}


and refactor accordingly.

Beyond that the only suggestion I would have is perhaps some better variable names (at least use a single naming style; if you don't already have one, use this: http://www.oracle.com/technetwork/java/codeconventions-135099.html#367).