Java Immutable class

All the wrapper classes of primitive date types are immutable, immutable is a concept whose state or values cannot be changed once they are declared. If we try to change any value of the immutable class objects then instead of changing its original value it will create a new Object of same type and return with the new value which we trying to change.

To implement Immutable Class in Java we need to follow the below steps.

Immutable class example

import java.util.Date;

final class ImmutableClass{
	private final int id;
	private final String name;
	private final String address;
	private final Date dob;	
	public ImmutableClass(int id, String name, String address,Date dob) { = id; = name;
		this.address = address;
	public int getId() {
		return id;
	public String getName() {
		return name;
	public String getAddress() {
		return address;

	public Date getDob() {
		return new Date();
	public String toString() {
		return "ImmutableClass [id=" + id + ", name=" + name + ", address=" + address + ", 
		dob=" + dob + "]";

public class ImmutableClassExample
	 public static void main(String ar[])
		 ImmutableClass immutableClass=new ImmutableClass(1, "std1", "addr1", new Date());