Java Map interface

Q4: Using the Map interface

1. Write a class that keeps Stock objects (StockNumber, name and quantity) in a Map. The class should be able to retrieve a particular Stock object from the Map by searching on its stock number. Demonstrate the class in an application.

2. You have a list of student ID numbers followed by the course number that each student is enrolled in. The listing is in no particular order. For example, if student 1 is in CS100 and CS200 while student 2 is in CS105 and MATH210, then the list might look like this:

1 CS100 , 2 MATH210, 2 CS105, 1 CS200

The list could be an array of objects, each object is an instance of a class with two attributes, the studentId and the course number.

1. Write a program that uses the HashMap class to map from an Integer (the student ID number) to an ArrayList of type String that holds each course that the student is enrolled in. The declaration should look like this: HashMap> students = new HashMap<>(); Iterate through the map and output the student ID number and all courses stored in the list for that student. The result should be a list of courses organized by student ID number.

2. Display the students list sorted by Student IDNumber where the list of courses is also sorted. ( You have to sort the keys but the ArrayList should also be sorted)