an Example for a Simple Immutable Object

MyImmutableObject.java

public final class MyImmutableObject {

	/**
	 * Both String and Integer Classes Are Immutable
	 */
	private final String ObjectName;

	private final Integer ObjectId;

	/**
	 * private Constructors so No Unplanned Constructions of an Object Occurs
	 * 
	 * @param ObjectName
	 * @param ObjectId
	 */
	private MyImmutableObject(String ObjectName, Integer ObjectId) {

		this.ObjectName = ObjectName;
		this.ObjectId = ObjectId;

	}

	/**
	 * to Create New Instances of the Immutable Object You Must pass by this
	 * method kind of a factory design pattern
	 * 
	 * @param ObjectName
	 * @param ObjectId
	 * @return
	 */
	public static MyImmutableObject getNewInstance(String ObjectName, Integer ObjectId) {

		return new MyImmutableObject(ObjectName, ObjectId);

	}

	// getter methods after all we have read access to an Immutable Object

	public Integer getObjectId() {
		return ObjectId;
	}

	public String getObjectName() {
		return ObjectName;
	}

	/**
	 * for Debugging
	 */
	public String toString() {
		return ObjectId + " " + ObjectName;
	}

	public static void main(String[] args) {
		MyImmutableObject obj = MyImmutableObject.getNewInstance("MyObject", 1);
		System.out.println(obj);
		modify(obj.getObjectId(), obj.getObjectName());
		System.out.println(obj);
	}

	public static void modify(Integer ObjectId, String ObjectName) {
		ObjectId = 2;
		ObjectName = "MyObjectModified";
	}

}