Question

finish the java programming

Create a new class named MyCharacterListTools that provides the API shown below.

This class does not need a constructor nor will any user-defined constructor be called by the

provided code in MainClassQ1.java.

◦ MyLinkedList createCharacterList(String str) – This method is to

return a MyLinkedList whose data items are the characters of str. All of the

characters must appear in the list and in the same order as they are given in str.

◦ void removeNonLetters(MyLinkedList list) – This method is to remove

from the list any spaces, numbers and punctuation characters (this is to be done inplace).

Letters of the alphabet are to be left in the list in the same order they were given.

For example, if the list contained {H_e_l_l_o_ _W_o_r_l_d_!} then after calling this

function, the list would hold {H_e_l_l_o_W_o_r_l_d}. You may use the built-in Java

static method Character.isLetter(char ch) to test whether the list items are

letters.

◦ boolean testEquality(MyLinkedList l1, MyLinkedList l2) – This

method is to compare two MyLinkedLists for equality. Two lists are considered

equal if their contents are the same and in the same order. Letter case should not be

observed (i.e. 'A' is equal to 'a', 'B' is equal to 'b', etc...). If the two lists are equal then

return true. Return false otherwise. The static built-in Java methods

Character.toLowerCase(char ch) and Character.toUpperCase(char

ch) may be used in this method.

Answer 1

Please follow comments in code

MyLinkedList.java :-

-----------------------------------

import java.util.ArrayList;

/**
*
* This class has list which saves characters of a String in ArrayList Container
*
*/
public class MyLinkedList {
  
   ArrayList<Character> characters = new ArrayList<Character>();
   //Add Character to list
   void add(char ch){
       Character cho = new Character(ch);
       characters.add(cho);
   }
   //get Element at given index
   char getItem(int index){
       return characters.get(index).charValue();
   }
   //get Size of List
   int getSize(){
       return characters.size();
   }
   //Remove item at given index
   void remove(int index){
       characters.remove(index);
   }

}

MyCharacterListTools.java :-

----------------------------------------------

/**
*
* This class implements methods mentioned in exercise
*
*/
public class MyCharacterListTools {
  
   MyLinkedList createCharacterList(String str){
      
       MyLinkedList list = new MyLinkedList();
       //Get each character in String and add to MyLinkedList
       for(int i = 0 ; i < str.length() ; i++){
          
           list.add(str.charAt(i));
       }
       return list;
   }
   void removeNonLetters(MyLinkedList list) {
       //Get each character in MyLinkedList
       for(int i = 0 ; i < list.getSize() ; i++){  
           //get Item and Check if it is Aplhabet or not
           //Ascii for Space is 32 , 33 is for Punctuation mark
           if(Character.isDigit(list.getItem(i)) ||
                   list.getItem(i) == 32 ||
                   list.getItem(i) == 33){
               //Remove it if not Aplhabet
               list.remove(i);
               --i;
           }
       }
   }
   boolean testEquality(MyLinkedList l1, MyLinkedList l2){
       //fist check sizes of both, if not equal return false
       if(l1.getSize() !=l2.getSize()){
           return false;
       }
       //Loop through Lists and check each character
       for(int i = 0 ; i < l1.getSize() ; i++){  
           if(Character.toLowerCase(l1.getItem(i)) != Character.toLowerCase(l2.getItem(i))){
               return false;
           }
       }
       return true;
   }
}

MainClassQ1.java :-

---------------------------------

public class MainClassQ1 {

   /**
   * @param args
   */
   public static void main(String[] args) {
       // TODO Auto-generated method stub
        //Create some test Strings
       String test1 = "H_e_l_l_o_ _W_o_r_l_d_!";
       String test2 = "H_e_6l_l_7o_ _W_o_r_999l_d_!";
       //create new object
       MyCharacterListTools tool = new MyCharacterListTools();
       //Create MyLinkedList for both Strings
       MyLinkedList list1 = tool.createCharacterList(test1);
       MyLinkedList list2 = tool.createCharacterList(test2);
       //Test
       tool.removeNonLetters(list1);
       tool.removeNonLetters(list2);
       System.out.println("Equality of both lists =="+tool.testEquality(list1, list2)) ;
   }

}