Question:
turn in the following source files:
Assignment10.java (This file does not need to be modified)
LinkedList.java (It needs to be modified)
ListIterator.java (This file does not need to be modified)
Skills to be Applied
In addition to what has been covered in previous assignments, the use of the following items, discussed in class, will probably be needed:
Linked Lists
Program Description
Class Diagram:
In the Assignment #10, you are given three files Assignment10.java, LinkedList.java, and ListIterator.java. You will need to add additional methods in the LinkedList class in the LinkedList.java file. The LinkedList will be tested using strings only.
Specifically, the following methods must be implemented in the LinkedList class:
(You should utilize listIterator() method already defined in the LinkedList class to obtain its LinkedListIterator object, and use the methods in the LinkedListIterator class to traverse from the first element to the last element of the linked list to define the following methods.)
1.
public String toString()
The toString method should concatenate strings in the linked list, and return a string of the following format:
{ Apple Banana Melon Orange }
Thus it starts with "{" and ends with "}", and there is a space between strings and "{" or "}". If the list is empty, it returns "{ }" with a space in between.
2.
public boolean isEmpty()
The isEmpty method returns true of the linked list is empty, false otherwise.
3.
public void addElement(Object element)
The addElement adds the parameter element at the parameter in the linked list in alphabetical order. For instance, if the linked list contains {Apple, Banana, Grape}, and a user tries to add "Carrot", then it should be added as:
{Apple, Banana, Carrot, Grape}.
4.
public Object removeElement(int index)
The removeElement removes the string (Object) at the parameter index and returns it. Note that this index starts with 0 just like array indices. For instance, if the linked list contains {Apple, Banana, Carrot, Grape} and the parameter index is 3, then "Grape" should be remove. If the parameter index is larger or smaller than the existing indices, it should throw an object of the IndexOutOfBoundsException class (and the content of the linked list should remain unchanged).
5.
public Object getElement(int index)
The getElement searches the string (Object) at the parameter index and returns it. Note that this index starts with 0 just like array indices. For instance, if the linked list contains {Apple, Banana, Carrot, Grape} and the parameter index is 3, then "Grape" will be returned. If the parameter index is larger or smaller than the existing indices, it should throw an object of the IndexOutOfBoundsException class (and the content of the linked list should remain unchanged).
6.
public void searchAndReplace(Object oldString, Object newString)
The searchAndReplace method searches all occurrences of the first parameter string (object) in the list, and replaces them with the second parameter string (object). If the parameter string does not exist in the linked list, then the linked list content will not change.
7.
public int indexOfLast(Object searchString)
The indexOfLast searches the parameter string (object) with the largest index, and returns its index. If the parameter string does not exist in the linked list, then it should return -1.
For instance, if the linked list contains { Apple Banana Banana Orange }, then after calling this method with the parameter "Banana", then it should return 2, which is the index of later Banana.
Test your LinkedList class with the given Assignment10.java file.
It is recommended to test boundary cases such as the cases when the linked list is empty, when it contains only one element, when adding/removing at the beginning or at the end of the linked list.