Java Object cloning

Object cloning means creating a copy of original object with different reference.

Object cloning can be of two types - Shallow cloning and Deep cloning.

Shallow cloning :-

Java Object Class already have a clone method. By default this clone method do shallow cloning.

As per java docs

Object clone method Creates and returns a copy of this object.
The precise meaning of "copy" may depend on the class of the object.
The general intent is that, for any object x, the expression:

1) x.clone() != x will be true
2) x.clone().getClass() == x.getClass() will be true, but these are not absolute requirements.
3) x.clone().equals(x) will be true, this is not an absolute requirement.

Select drop-down list in jquery

  Get selected value using class :-

$(".drop_down_class").val();

Get selected value using Id :-

$("#drop_down_id").val();

Get text of selected value :-

$("#drop_down_id").text();

How to sort a hashset

Covert set into list than sort it using collection utill

A HashSet does not guarantee any order of its elements

Set unSortedHashSet = new HashSet();

List sortedList = new ArrayList(unSortedHashSet);

Collections.sort(sortedList);