Inheritance using abstract class

package inherit;

abstract class Student {
        private int id;
        private String name;
        private String address;
        private String email;
        protected double basicFee;

        public Student(int id, String name, String address, String email) {
                super();
                this.id = id;
                this.name = name;
                this.address = address;
                this.email = email;
        }

        public int getId() {
                return id;
        }

        public void setId(int id) {
                this.id = id;
        }

        public String getName() {
                return name;
        }

        public void setName(String name) {
                this.name = name;
        }

        public String getAddress() {
                return address;
        }

        public void setAddress(String address) {
                this.address = address;
        }

        public String getEmail() {
                return email;
        }

        public void setEmail(String email) {
                this.email = email;
        }

        public double getBasicFee() {
                return basicFee;
        }

        public void setBasicFee(double basicFee) {
                this.basicFee = basicFee;
        }

        public abstract double feeCalculate();
        public abstract void showStudent();
}

class GradStudent extends Student {
        int numberOfCourse;
        double grade;

        public GradStudent(int id, String name, String address, String email,
                        int numberOfCourse, double grade) {
                super(id, name, address, email);
                this.numberOfCourse = numberOfCourse;
                this.grade = grade;
        }

        public int getNumberOfCourse() {
                return numberOfCourse;
        }

        public void setNumberOfCourse(int numberOfCourse) {
                this.numberOfCourse = numberOfCourse;
        }

        public double getGrade() {
                return grade;
        }

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

        @Override
        public double feeCalculate() {
                return (this.basicFee + this.numberOfCourse * 100);
        }

        @Override
        public void showStudent() {

                System.out.println("\nStudent Information");
                System.out.println("ID:\t\t" + this.getId());
                System.out.println("Type:\t\tGraduate");
                System.out.println("Name:\t\t" + this.getName());
                System.out.println("Address:\t" + this.getAddress());
                System.out.println("Grade:\t\t" + this.getGrade());
                System.out.println("Fee:\t\t" + this.feeCalculate());
        }

}

class UnderGradStudent extends Student {
        char grade;
        double compCourseFee;
        double prereqFee;

        public UnderGradStudent(int id, String name, String address, String email,
                        char grade, double compCourseFee, double prereqFee) {
                super(id, name, address, email);
                this.grade = grade;
                this.compCourseFee = compCourseFee;
                this.prereqFee = prereqFee;
        }

        public char getGrade() {
                return grade;
        }

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

        public double getCompCourseFee() {
                return compCourseFee;
        }

        public void setCompCourseFee(double compCourseFee) {
                this.compCourseFee = compCourseFee;
        }

        public double getPrereqFee() {
                return prereqFee;
        }

        public void setPrereqFee(double prereqFee) {
                this.prereqFee = prereqFee;
        }

        @Override
        public double feeCalculate() {
                return (this.basicFee + this.compCourseFee + this.prereqFee);
        }

        @Override
        public void showStudent() {

                System.out.println("\nStudent Information");
                System.out.println("ID:\t\t" + this.getId());
                System.out.println("Type:\t\tUnder Graduate");
                System.out.println("Name:\t\t" + this.getName());
                System.out.println("Address:\t" + this.getAddress());
                System.out.println("Grade:\t\t" + this.getGrade());
                System.out.println("Fee:\t\t" + this.feeCalculate());
        }
}

public class Dec02Inheritance {

        public static void main(String[] args) {

                GradStudent gs1 = new GradStudent(100, "Siken Man", "Teku",
                                "sikenman@gmail.com", 5, 2.3);
                UnderGradStudent ugs1 = new UnderGradStudent(102, "Amit Bajaj", "Ason",
                                "amitbajaj@yahoo.com", 'C', 12000, 8000);

                gs1.showStudent();
                ugs1.showStudent();

        }

}