17.2 MyLinkedList (Individual Assignment)

Required Skills Inventory

Write concrete classes that implement Java Interfaces according to specifications given in UML.

Implement the major functionality of an array list.

Implement the major functionality of a linked list.

You are not allowed to use any of the standard Java collection types (like ArrayList) for this assignment. You are also not allowed to use arrays for this assignment.

Problem Description and Given Info

For this assignment you are given the following Java source code files:

MyListIterator.java (This file is complete make no changes to this file)

MyList.java (This file is complete make no changes to this file)

MyLinkedList.java (You must complete this file)

Main.java (You may use this file to write code to test your MyLinkedList)

You must complete the public class named MyLinkedList with fields and methods as defined below. Your MyLinkedList will implement the MyList interface that is provided in the myList.java file.

^{UML CLass Diagram: MyLinkedList}

Structure of the Fields

As described by the UML Class Diagram above, your MyLinkedList class must have the following fields:

a private field named head of type Node, initialized to null

a private field named size of type int, initialized to 0

Structure of the Methods

As described by the UML Class Diagram above, your MyArrayList class must have the following methods:

a public method named addToEnd that takes an Object argument and returns nothing

a public method named insertAt that takes an int argument and an Object argument and returns nothing

a public method named removeAt that takes an int arguments and returns nothing

a public method named getAt that takes an int argument and returns an Object

a public method named getSize that takes no arguments and returns an int

Note that:

these methods are declared in the MyList interface. You will be implementing these methods in this MyLinkedList concrete derived class.

the getIterator method and the MyListIterator class are already implemented for you in the MyLinkedList class. Make no changes to this code.

the Node class is already implemented for you in the MyLinkedList class. Make no changes to this code.

Additional Information

MyLinkedList

This concrete class will store its elements in Node objects. Each Node object has a data variable that stores the element and a next variable that stores a reference to the next Node object in the list. Each instance of MyLinkedList has a Node variable called head. When size is 0 then head is null. When size is not 0 then head is a reference to the first Node object. For each Node object in the list, if this Nodes next is null then this is the last Node in the list.

addToEnd method

Appends new item to end of list. For example: given the list {1, 2, 3} and an instruction to addToEnd(99), the result would be this {1, 2, 3, 99}.

this method will construct a new Node object whos data is the element to be added, and place this Node appropriately into the list.

insertAt method

Inserts a new Node at the specified index in the list. Given the list {1, 2, 3} and an instruction to insertAt(1, 99), the result would be this {1, 99, 2, 3}.

Throws a NoSuchElementException if the specified index is less than 0 or greater than size.

this method will construct a new Node object whos data is the element to be added, and place this Node appropriately into the list.

removeAt method

Removes the element at the specified index. For example: given the list {1, 2, 3} and an instruction to removeAt(1), the result would be this {1, 3}.

Throws a NoSuchElementException if the specified index is less than 0 or greater than or equal to size.

getAt method

Returns the item at the specified index. For example: given the list {1, 2, 3} and an instruction to getAt(1), the return value would be 2.

Throws a NoSuchElementException if the specified index is less than 0 or greater than or equal to size.

getSize method

Returns the number of elements currently stored in the list.

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MyLinkedList.java

// Complete the implementation of your MyLinkedList class in this file

public class MyLinkedList implements MyList { // Implement the required fields and methods here // Do not alter the code below public MyListIterator getIterator() { return new MyLinkedListIterator(); } private class MyLinkedListIterator implements MyListIterator { Node currentNode = null;

@Override public Object next() { if (currentNode != null) currentNode = currentNode.next; else currentNode = head;

return currentNode.data; }

@Override public boolean hasNext() { if (currentNode != null) return currentNode.next != null; else return head != null; } } class Node { public Object data = null; public Node next = null; } }

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MyList.java

/** This interface specifies the basic operations of any list-like object. This interface contains a variation of the methods of the standard java.util.List interface. */ public interface MyList { /** Adds an element at the end of the list. */ public void addToEnd(Object o);

/** Inserts an element at the specified index Throws NoSuchElementException if index is out of bounds. */ public void insertAt(int index, Object o);

/** Removes the element at the specified index Throws NoSuchElementException if index is out of bounds. */ public void removeAt(int index); /** Returns the element at the specified index Throws NoSuchElementException if index is out of bounds. */ public Object getAt(int index); /** Returns the size of the list. @return the number of elements in the list */ public int getSize(); /** Returns a list iterator for this list. @return a list iterator for this list */ public MyListIterator getIterator(); } _____________________________________________________

MyListIterator.java

/** A list iterator allows access of a position in a list. This interface contains a subset of the methods of the standard java.util.ListIterator interface. The methods for backward traversal are not included. */ public interface MyListIterator { /** Moves the iterator past the next element. @return the traversed element */ Object next(); /** Tests if there is an element after the iterator position. @return true if there is an element after the iterator position */ boolean hasNext(); }

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Main.java

// you may use this file to wrote and run code to test your MyArrayList class

public class Main { public static void main(String[] args) { } }

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I need the MyLinkedList.java, MyList.java, MyListIterator.java, and the Main.java.