I would like to have a simple Java program that demonstrates Immutable objects and Builder pattern concepts

Note: The same program must demonstrate these 2 concepts using a common object.

2. Write a simple Java program that creates a collection of objects of type String. Populate the collection with sample data and use an iterator and a while loop to print the contents.

3. Write a simple Java program that creates a Map with keys of type Integer and values of type String. Populate the map with some sample data. Then do the following.
a. Use a foreach loop to go through each pair of the map (Hint: use the entrySet method of the Map interface)
b. and on iteration of the for loop, print out the current key and value represented by the iteration.