CSC 217 Lab 07 Implement and Test Custom ArrayList
The design of the student schedule functionality calls for a custom implementation of an array list that doesn’t allow for null elements or duplicate elements as defined by the equals() method.
You will use test driven development to implement the custom ArrayList. Each section below describes the methods that you will be implementing.
Create edu.ncsu.csc216.pack_scheduler.util Package
Create the edu.ncsu.csc216.pack_scheduler.util package in the src/ folder of PackScheduler.
Create ArrayList Class
Create ArrayList in the src/ folder of the edu.ncsu.csc216.pack_scheduler.util package.
ArrayList should extend java.util.AbstractList and should have a generic type parameter, E. Your class header should look like the following:
public class ArrayList<E> extends AbstractList<E> {
Create ArrayListTest Class
Create ArrayListTest in the test/ folder of the edu.ncsu.csc216.pack_scheduler.util package. You will need to create the edu.ncsu.csc216.pack_scheduler.util package in the test/ source folder.
When testing, you should work with a list of Strings. Those will be easier to test that more complex objects like Courses.
Implement ArrayList State
ArrayList has the following state:
INIT_SIZE: a constant value for initializing the list size. The value should be 10.list: an array of typeEsize: the size of the list
Test and Implement ArrayList.ArrayList()
Write a test for ArrayList’s constructor. You should implement ArrayList.size() to help with testing the constructor.
The constructor of ArrayList should create an empty ArrayList (e.g., size is zero) with a list of capacity INIT_SIZE. Remember, you cannot directly construct an array of type E. Instead you have to create an array of Objects and cast to an array of type E. You may add the annotation @SuppressWarnings("unchecked") above the constructor to remove the warning about an unchecked cast.
Implement ArrayList.add(int, E)
Write tests for ArrayList.add(int, E). You should implement ArrayList.get() so that you can test the contents of the list after adding elements.
Override and implement the ArrayList.add(int, E) method that will add the element to the given index. If the element is inserted at the front or the middle of the list, the other elements are shifted to make room. If the size is equal to the capacity, the list should automatically double in capacity to make room for the new element. The private method growArray() is used to double the capacity. You may create a private method or implement the grow functionality in the add() method.
If the element to add is null, the method should throw a NullPointerException.
If the element to add is a duplicate of an element already in the list as determined by the equals() method, the method should throw an IllegalArgumentException.
If the index is out of range (index < 0 || index > size()), the method should throw an IndexOutOfBoundsException.
Implement ArrayList.remove(int)
Write tests for ArrayList.remove(int). ArrayList.remote(int) should return the element removed and the return type should be E.
Override and implement the ArrayList.remove(int) method so that it will remove elements at the given index. If an element at the front or middle of the list is removed, the elements are left shifted to close the gap. Don’t forget to set the element at size-1 to null after the left shift to remove the extra reference.
If the index is out of range (index < 0 || index >= size()), the method should throw an IndexOutOfBoundsException.
Implement ArrayList.set(int, E)
Write tests for ArrayList.set(int, E). ArrayList.set(int, E) should return the original element at the location and the return type should be E.
Override and implement the ArrayList.set(int, E) method so that the element at the specified index is replaced with the given element.
If the element to set is null, the method should throw a NullPointerException.
If the element to set is a duplicate of an element already in the list as determined by the equals() method, the method should throw an IllegalArgumentException.
If the index is out of range (index < 0 || index >= size()), the method should throw an IndexOutOfBoundsException.
Implement ArrayList.get(int)
Write tests for ArrayList.get(int) that consider when the index is out of range. ArrayList.get(int) returns the element at the index and the return type is E.
Override and implement the ArrayList.get(int) method so that it will return elements at the given index.
If the index is out of range (index < 0 || index >= size()), the method should throw an IndexOutOfBoundsException.
Push to GitHub
Push your PackScheduler project to GitHub
- Add the unstaged changes to the index.
- Commit and push changes. Remember to use a meaningful commit message describing how you have changed the code.
Reminder: Staging and Pushing to GitHub
GitHub Resources: