Question

Writing 3 Java Classes for Student registration

/**
* A class which maintains basic information about an academic course.
*/

public class Course {
  
/**
* Attributes.
*/
private String code;
private String title;
private String dept; // name of department offering the course
private int credits;

/**
* Constructor.
*/
public Course(String code, String title, int credits) {
// TODO : initialize instance variables, use the static method defined in
// Registrar to initialize the dept name variable
  

}

/**
* Accessor methods.
*/
// TODO: define a setter and a getter method for each of the instance variables

/**
* public methods.
*/
@Override
public String toString() {
// TODO: implement so that a string is returned in the following format:
// "INFS 612 Communication Systems�

}

public String fullString() {
// TODO: implement so that a string is returned in the following format:
//"INFS 612 Communication Systems, (3) credit hours.�

}

}

/**
* A sub-class which extends the Course class to keep track of a student
* registration in a course, and also perform
*/
public class TranscriptEntry extends Course {
/**
* Attributes
*
*/
private String semester;
private int year;
private String grade;
private boolean active;
  
public TranscriptEntry(Course c, String semester, int year) {
// TODO
// note: active must be initialized to true.

}   
  
/**
* Accessor methods methods.
* // TODO
* define a setter and a getter for each instance variable.
* note: Do not write accessor methods for the active variable since its an internal variable:
* if a course is flagged active, then the student is currently enrolled in that course.
* When a grade is posted for a course, active is set to false.
*/
  
  
/**
* Public Methods.
*
*/
  
public boolean isActive() {
//TODO
}

  
@Override
public String toString() {
// return a string with the following format:
// "\tINFS 510 Database Systems, credits: 3, GRADE: A"
// And if the student does not have an assigned grade, then the string value should be:
// "\tINFS 510 Database Systems, credits: 3"
//TODO
}
}

/**
* The main class in the student registration program..
* This class defines public methods to provide the following functionality:
* - maintains the course catalog.
* - registers and drop courses for students
* - at the end of semester, post grades
*   
*/
import java.util.Scanner;

public class Registrar {
  
/**
* Attributes.
*/
private Student [] students;
private int numStudents; // keeps track of the students array size
private Course [] courseCatalog;
private int numCourses; // keeps track of the courseCatalog array size
private String semester;
private int year;

/**
* Constructor.
*/
public Registrar(String semester, int year) {
// TODO.
// note: maximum number of students is 100, and maximum number of courses is 50.
//
}

/**
* Accessor methods.
*/
public void setSemester(String semester) { this.semester=semester;}
public String getSemester() { return semester; }

public void setYear(int year) { this.year=year;}
public int getYear() { return year; }

/**
* Public methods.
*/
public boolean addCourse(String code, String title, int hours) {
// if courseCatalog is full , return false, otherwise, add course to the catalog.
// TODO
}

public String getCourseCatalog() {
String str="";
for (Course c : courseCatalog)
if (c == null) break;
else str = str + c.fullString() +"\n";
return str;
}

public boolean addStudent(String fname, String lname, long id, String major,
String degree, String highSchool) {
// if the students array is full, return false.
// otherwise add the student information to the students arrays
// TODO
}

public boolean addStudent(String fname, String lname, long id, String major,
String degree, String uMajor, String uInstit) {
// an overloaded method which does the sam as the other addStudent method
// TODO
}

public boolean register(long id, String courseCode) {
// first check if the course is offered (by searching courseCatalog array using courseCode), if
// the course is not found return false.
// then find the student object in the students array using their id number, if no student is found
// return false.
// otherwise register the student in the class and return true.
// TODO
}
  
public boolean drop(long id, String courseCode) {
// Find the student object in the students array using their id number, if no student is found
// return false. otherwise drop the course for the student.
// TODO
}
  
public boolean postGrade(long id, String courseCode, int score) {
// Find the student object in the students array using their id number, if no student is found
// return false. otherwise post a course grade for the student.
// TODO
}
  
  
public String getProgress(long gnum, String semester, int year) {
Student s = findStudent(gnum);
if (s == null)
return "Student "+gnum+" not found";
String str = String.format(" %s\n", s.toString());
return str+s.getClassList(semester, year);
}

public static String getDeptName(String code) {
// given a course code, this static method will return the name
// of the academic department to which the course belong
String dept = (new Scanner(code)).next();
  
if (dept.equalsIgnoreCase("CS"))
return "Computer Science";
else if (dept.equalsIgnoreCase("INFS"))
return "Information Systems";
else if (dept.equalsIgnoreCase("IT"))
return "Information Tecchnoloy";
else if (dept.equalsIgnoreCase("MATH"))
return "Mathematics";
else if (dept.equalsIgnoreCase("PHYS"))
return "Physics";
else return null;
}
  
  
/**
* Private methods.
* you will need few helper methods.
*/

  
  
}

Answer 1

Course.java:

public class Course {

   /**
   * Attributes.
   */
   private String code;
   private String title;
   private String dept; // name of department offering the course
   private int credits;

   /**
   * Constructor.
   */
   public Course()
   {
      
   }

   public Course(String code2, String title2, int credits2) {
       // TODO Auto-generated constructor stub
       this.code = code2;
this.title = title2;
this.dept = Registrar.getDeptName(code2);
this.credits = credits2;
   }
   /**
   * Accessor methods.
   */
   // TODO: define a setter and a getter method for each of the instance
   // variables

   public void setCode(String code) {
       this.code = code;
   }

   public String getTitle() {
       return title;
   }

   public void setTitle(String title) {
       this.title = title;
   }

   public String getDept() {
       return dept;
   }

   public void setDept(String dept) {
       this.dept = dept;
   }

   public int getCredits() {
       return credits;
   }

   public void setCredits(int credits) {
       this.credits = credits;
   }

   /**
   * public methods.
   */
   @Override
   public String toString() {
       // TODO: implement so that a string is returned in the following format:
       // "INFS 612 Communication Systems�
       return code+" "+title;

   }

   public String fullString() {
       // TODO: implement so that a string is returned in the following format:
       // "INFS 612 Communication Systems, (3) credit hours.�
       return code+" "+title+",("+credits+") credit hours.";

   }
   public String getCode() {
       // TODO Auto-generated method stub
       return code;
   }

}

TranscriptEntry.java:

/**
* A sub-class which extends the Course class to keep track of a student
* registration in a course, and also perform
*/
public class TranscriptEntry extends Course {
   /**
   * Attributes
   *
   */
   private String semester;
   public String getSemester() {
       return semester;
   }

   public void setSemester(String semester) {
       this.semester = semester;
   }

   public String getGrade() {
       return grade;
   }

   public void setGrade(String grade) {
       this.grade = grade;
   }

   private int year;
   private String grade;
   private boolean active;

   public TranscriptEntry(Course c, String semester, int year) {
       // TODO
       // note: active must be initialized to true.
      
       super(c.getCode(),c.getTitle(),c.getCredits());
   this.semester=semester;
this.year=year;
this.active=true;
   }

   /**
   * Accessor methods methods. // TODO define a setter and a getter for each
   * instance variable. note: Do not write accessor methods for the active
   * variable since its an internal variable: if a course is flagged active,
   * then the student is currently enrolled in that course. When a grade is
   * posted for a course, active is set to false.
   */

   /**
   * Public Methods.
   *
   */

   public boolean isActive() {
       // TODO
       return this.active;
   }

   @Override
   public String toString() {
       // return a string with the following format:
       // "\tINFS 510 Database Systems, credits: 3, GRADE: A"
       // And if the student does not have an assigned grade, then the string
       // value should be:
       // "\tINFS 510 Database Systems, credits: 3"
       // TODO
       if(grade.equalsIgnoreCase("")){
   return "\t"+getCode()+" "+getTitle()+", credits: "+getCredits();
   }
       else{
   return "\t"+getCode()+" "+getTitle()+", credits: "+getCredits()+", GRADE: "+grade;
   }
   }
}

Registrar.java:

/**
* The main class in the student registration program..
* This class defines public methods to provide the following functionality:
* - maintains the course catalog.
* - registers and drop courses for students
* - at the end of semester, post grades
*   
*/
import java.util.Scanner;

public class Registrar {

   /**
   * Attributes.
   */
   private Student[] students;
   private int numStudents; // keeps track of the students array size
   private Course[] courseCatalog;
   private int numCourses; // keeps track of the courseCatalog array size
   private String semester;
   private int year;

   /**
   * Constructor.
   */
   public Registrar(String semester, int year) {
       // TODO.
       // note: maximum number of students is 100, and maximum number of
       // courses is 50.
       //
       this.semester = semester;
this.year = year;
students = new Student[100];
courseCatalog = new Course[50];
numStudents = 0;
numCourses = 0;
   }

   /**
   * Accessor methods.
   */
   public void setSemester(String semester) {
       this.semester = semester;
   }

   public String getSemester() {
       return semester;
   }

   public void setYear(int year) {
       this.year = year;
   }

   public int getYear() {
       return year;
   }

   /**
   * Public methods.
   */
   public boolean addCourse(String code, String title, int hours) {
       // if courseCatalog is full , return false, otherwise, add course to the
       // catalog.
       // TODO
       if (numCourses < courseCatalog.length) {
   Course course = new Course(code, title, hours);
   courseCatalog[numCourses] = course;
   numCourses += 1;
   return true;
   }
       else
   return false;
   }

   public String getCourseCatalog() {
       String str = "";
       for (Course c : courseCatalog)
           if (c == null)
               break;
           else
               str = str + c.fullString() + "\n";
       return str;
   }

   public boolean addStudent(String fname, String lname, long id, String major, String degree, String highSchool) {
       // if the students array is full, return false.
       // otherwise add the student information to the students arrays
       // TODO
       if(numStudents<students.length){
   Student student = new Student(fname,lname,id,major,degree,highSchool);
   students[numStudents]=student;
   numStudents+=1;
   return true;
   }else
   return false;
   }

   public boolean addStudent(String fname, String lname, long id, String major, String degree, String uMajor,
           String uInstit) {
       // an overloaded method which does the sam as the other addStudent
       // method
       // TODO
       if(numStudents<students.length){
           Student student = new Student(fname,lname,id,major,degree,uMajor,uInstit);
           students[numStudents]=student;
numStudents+=1;
return true;
}else
return false;
       }
      
  

   public boolean register(long id, String courseCode) {
       // first check if the course is offered (by searching courseCatalog
       // array using courseCode), if
       // the course is not found return false.
       // then find the student object in the students array using their id
       // number, if no student is found
       // return false.
       // otherwise register the student in the class and return true.
       // TODO
       boolean courseCodeAvailable=false;
for(int i=0;i<numCourses;i++){
if(courseCatalog[i].getCode().equalsIgnoreCase(courseCode)){
courseCodeAvailable=true;
break;
}
}
if (!courseCodeAvailable){
return false;
}

boolean studentIdAvailable=false;
for(int i=0;i<numStudents;i++){
if(students[i].getId()==id){
studentIdAvailable=true;
students[i].setCourseCode(courseCode);
break;
}
}

if (!studentIdAvailable){
return false;
}

return true;
   }

   public boolean drop(long id, String courseCode) {
       // Find the student object in the students array using their id number,
       // if no student is found
       // return false. otherwise drop the course for the student.
       // TODO
       boolean studentIdAvailable=false;
   for(int i=0;i<numStudents;i++){
   if(students[i].getId()==id){
   studentIdAvailable=true;
   students[i].setCourseCode(null);;
   break;
   }
   }
   if (!studentIdAvailable){
   return false;
   }

   return true;
   }

   public boolean postGrade(long id, String courseCode, int score) {
       // Find the student object in the students array using their id number,
       // if no student is found
       // return false. otherwise post a course grade for the student.
       // TODO
       boolean studentIdAvailable=false;
   for(int i=0;i<numStudents;i++){
   if(students[i].getId()==id){
   studentIdAvailable=true;
   students[i].setGrade(calculateGrade(score));
   break;
   }
   }

   if (!studentIdAvailable){
   return false;
   }

   return true;
   }

   public String getProgress(long gnum, String semester, int year) {
       Student s = findStudent(gnum);
       if (s == null)
           return "Student " + gnum + " not found";
       String str = String.format(" %s\n", s.toString());
       return str + s.getClassList(semester, year);
   }

  
   public static String getDeptName(String code) {
       // given a course code, this static method will return the name
       // of the academic department to which the course belong
       String dept = (new Scanner(code)).next();

       if (dept.equalsIgnoreCase("CS"))
           return "Computer Science";
       else if (dept.equalsIgnoreCase("INFS"))
           return "Information Systems";
       else if (dept.equalsIgnoreCase("IT"))
           return "Information Tecchnoloy";
       else if (dept.equalsIgnoreCase("MATH"))
           return "Mathematics";
       else if (dept.equalsIgnoreCase("PHYS"))
           return "Physics";
       else
           return null;
   }

   /**
   * Private methods. you will need few helper methods.
   */
   private Student findStudent(long gnum) {
       boolean studentIdAvailable;
       for(int i=0;i<numStudents;i++){
   if(students[i].getId()==gnum){
   studentIdAvailable=true;
   return students[i];
   }
   }
   return null;
   }
  
   public String calculateGrade(int score)
   {      
       String grade ="";
       if(score>=80){
       grade = "A";
       }else if(score>=60 && score<80){
       grade = "B";
       }
       else if(score>=40 && score<60){
       grade = "C";
       }
       else {
       grade = "D";
       }
          return grade;
   }
}

Student.java:

public class Student {
  
   String fname;
   String lname;
   long id;
   String major;
   String degree;
   String uMajor;
   String uInstit;
   String highSchool;
   String courseCode;
   String grade;
  
   public String getCourseCode() {
       return courseCode;
   }
   public void setCourseCode(String courseCode) {
       this.courseCode = courseCode;
   }
   public String getGrade() {
       return grade;
   }
   public void setGrade(String grade) {
       this.grade = grade;
   }
   Student(String fname,String lname,long id,String major,String degree, String highSchool)
   {
       this.fname =fname;
       this.lname = lname;
       this.id =id;
       this.major = major;
       this.degree = degree;
       this.highSchool = highSchool;
  
   }
   Student(String fname, String lname, long id, String major, String degree, String uMajor,
           String uInstit)
   {
       this.fname =fname;
       this.lname = lname;
       this.id =id;
       this.major = major;
       this.degree = degree;
       this.uMajor = uMajor;
       this.uInstit = uInstit;
      
   }
   public String getFname() {
       return fname;
   }
   public void setFname(String fname) {
       this.fname = fname;
   }
   public String getLname() {
       return lname;
   }
   public void setLname(String lname) {
       this.lname = lname;
   }
   public long getId() {
       return id;
   }
   public void setId(long id) {
       this.id = id;
   }
   public String getMajor() {
       return major;
   }
   public void setMajor(String major) {
       this.major = major;
   }
   public String getDegree() {
       return degree;
   }
   public void setDegree(String degree) {
       this.degree = degree;
   }
   public String getuMajorl() {
       return uMajor;
   }
   public void setuMajorl(String uMajorl) {
       this.uMajor = uMajorl;
   }
   public String getuInstit() {
       return uInstit;
   }
   public void setuInstit(String uInstit) {
       this.uInstit = uInstit;
   }
   public String getClassList(String semester, int year) {
       // TODO Auto-generated method stub
       return null;
   }
   }

Main.java:

public class Main {
   public static void main(String args[])
   {
       Course c = new Course("INFS 612","Communication Systems",3);
       TranscriptEntry te = new TranscriptEntry(c, "2nd",2019);
       Registrar r = new Registrar("2nd",2019);
       r.addCourse("INF2","DBMS", 150);
       r.addStudent("John", "Wick", 1, "ing","ME","Xaviers");
       System.out.println(te.fullString());
   }
}

Sample Output: