Question

Java help:

1.1) Create a class TA  that extends class Student.
1.2) Add a variable to the TA class to represent the course the student is TA'ing.
1.3) Provide a constructor for the class so the code in the PeopleFactory will work as provided.
1.4) Provide a toString() method for the TA  class so that TA's will output as shown in the sample code.

Provide a class Staff so that you can un-comment the lines of code in the PeopleFactory class that creates Staff objects and so the output is like the sample shown in the Tester. You will have to do the following:

2.1) Create a class Staff that extends class Person.
2.2) Add variables to the Staff  class to represent the department and position of the staff member.
2.3) Provide a constructor for the class so the code in the PeopleFactory will work as provided.
2.4) Provide a toString() method for the Staff class so that Staff objects will output as shown in the sample code.

Provided code:

public class PeopleFactory {

   public static ArrayList getSomePeople() {

      ArrayList people = new ArrayList();

      people.add(new Person("Lou"));
      people.add(new Student("Sue"));
      people.add(new Student("Anne"));
      people.add(new Professor("Morrison"));
      people.add(new Student("Frank"));
      people.add(new Person("Britney"));
      people.add(new Professor("Nel"));

      people.add(new TA("Terri", "COMP1405"));
      people.add(new TA("Glenn", "COMP1405"));

      people.add(new Staff("Linda", "Comp Sci", "Administrator"));
      people.add(new Staff("John", "Comp Sci", "Tech Support"));

      return people;

   }

public class Student extends Person{

   private static int nextStudentNumber = 12345; //initial value of transaction numbers

   private int studentNumber;

   public Student(String aName){
      super(aName);

      studentNumber = nextStudentNumber;
      nextStudentNumber++;
   }

   /*
   public boolean equals(Object anObject){
      if(!(anObject instanceof Student) ) return false;
      return name.equals(((Student) anObject).getName());
   }
   */

   public String toString(){

      return super.toString() + " #" + studentNumber;
   }

} 

public class Professor extends Person{

   private static int nextEmployeeNumber = 12345; //initial value of transaction numbers

   private int employeeNumber;

   public Professor(String aName){
      super(aName);

      employeeNumber = nextEmployeeNumber;
      nextEmployeeNumber++;
   }

   public String toString(){

      return "Prof. " +  super.toString() + " emp#" + employeeNumber;
   }

}

public class Person{

   private static int nextSocialInsuranceNumber = 100000000; //initial value of transaction numbers

   private String name = "UNNAMED";
   private int sinNumber;

   public Person(String aName){
      sinNumber = nextSocialInsuranceNumber;
      nextSocialInsuranceNumber++;
      name = aName;
   }

   public boolean equals(Object anObject){
      if(!(anObject instanceof Person) ) return false;
      return name.equals(((Person) anObject).getName());
   }

   public String getName(){return name;
   }
   public String getSinNumber(){return name;
   }

   public String toString(){
      return name;
   }

}

public class TA extends Student{

    public TA(String aName) {
        super(aName);
    }

}

import java.util.ArrayList;

public class Tester{

   public static void main(String[] args){

      //Create ArrayLists to hold some Persons objects and the different class names
      ArrayList people = PeopleFactory.getSomePeople();

      ArrayList classNames = new ArrayList();

      //fill the classNames ArrayList with the different kinds of people
      //This loop makes sure a class name is only added once

      for(Person aPerson : people){

         //Determine the real class name of the person
         String nameOfPersonsClass = aPerson.getClass().getName();

         //check if the class name is already in the classNames collection
         boolean found = false;
         for(String aClassName : classNames){
            if(aClassName.equals(nameOfPersonsClass)) found = true;
         }

         //if the class name was not already there then add it
         if(found == false)
            classNames.add(nameOfPersonsClass);
      }


      //Print out how many different kinds of people there are and their class names
      System.out.println(classNames.size() + " kinds of people: " + classNames);

      System.out.println(" ");
      System.out.println("The kinds of people");
      System.out.println("=====================");

      //Use destructive iteration to go over the classes

      while(!classNames.isEmpty()){

         //find and remove a class name
         String className = classNames.get(0);
         classNames.remove(className);

         System.out.println(" ");
         System.out.println(className + "s:");
         System.out.println("-----------");

         //Loop over the people and print them if their class name
         //matches the current class being displayed

         for(Person aPerson : people){
            if(aPerson.getClass().getName().equals(className))
               System.out.println(aPerson);
         }

      }

   } //end main

} //end class Tester

Answer 1

public class PeopleFactory { public static ArrayList getSomePeople() { ArrayList people = new ArrayList(); people.add(new Person("Lou")); people.add(new Student("Sue")); people.add(new Student("Anne")); people.add(new Professor("Morrison")); people.add(new Student("Frank")); people.add(new Person("Britney")); people.add(new Professor("Nel")); people.add(new TA("Terri", "COMP1405")); people.add(new TA("Glenn", "COMP1405")); people.add(new Staff("Linda", "Comp Sci", "Administrator")); people.add(new Staff("John", "Comp Sci", "Tech Support")); return people; }

public class Student extends Person{ private static int nextStudentNumber = 12345; //initial value of transaction numbers private int studentNumber; public Student(String aName){ super(aName); studentNumber = nextStudentNumber; nextStudentNumber++; } /* public boolean equals(Object anObject){ if(!(anObject instanceof Student) ) return false; return name.equals(((Student) anObject).getName()); } */ public String toString(){ return super.toString() + " #" + studentNumber; } } 

public class Professor extends Person{ private static int nextEmployeeNumber = 12345; //initial value of transaction numbers private int employeeNumber; public Professor(String aName){ super(aName); employeeNumber = nextEmployeeNumber; nextEmployeeNumber++; } public String toString(){ return "Prof. " + super.toString() + " emp#" + employeeNumber; } }

import java.util.ArrayList; public class Tester{ public static void main(String[] args){ //Create ArrayLists to hold some Persons objects and the different class names ArrayList<Person> people = PeopleFactory.getSomePeople(); ArrayList<String> classNames = new ArrayList<String>(); //fill the classNames ArrayList with the different kinds of people //This loop makes sure a class name is only added once for(Person aPerson : people){ //Determine the real class name of the person String nameOfPersonsClass = aPerson.getClass().getName(); //check if the class name is already in the classNames collection boolean found = false; for(String aClassName : classNames){ if(aClassName.equals(nameOfPersonsClass)) found = true; } //if the class name was not already there then add it if(found == false) classNames.add(nameOfPersonsClass); } //Print out how many different kinds of people there are and their class names System.out.println(classNames.size() + " kinds of people: " + classNames); System.out.println(" "); System.out.println("The kinds of people"); System.out.println("====================="); //Use destructive iteration to go over the classes while(!classNames.isEmpty()){ //find and remove a class name String className = classNames.get(0); classNames.remove(className); System.out.println(" "); System.out.println(className + "s:"); System.out.println("-----------"); //Loop over the people and print them if their class name //matches the current class being displayed for(Person aPerson : people){ if(aPerson.getClass().getName().equals(className)) System.out.println(aPerson); } } } //end main } //end class Tester public class TA extends Student {

private String course;

  public Student(String aName, String aCourse){

super(aName);

course = aCourse

} // End Constructor to TA class

  public String toString(){

return aCouse+" TA:" + super.toString();

} // End toString function of TA Class

} // End TA Class

public class Staff extends Person {

private String department;

private String position;

public Staff(String aName,String aDepartment,String aPosition) {

  super(aName);

department = aDepartment;

position = aPosition;

}//end constructor

  

public String toString(){

return super.toString() + " Staff: " + department+", "+position; 

} // End toString function of Staff Class

}//End of Staff class