Using any application of your choice, write a Java program that meets the following requirements:
It has an abstract class that contains a student number;
Include get() and set() methods for the abstract class where the student number is set/get;
Create three child classes, for firstYear, secondYear and thirdYear.
Each class must display a distinct announcement for first years, second years and third years.
Sure! Here's a Java program using the Eclipse IDE that meets your requirements:
```java
abstract class Student {
private String studentNumber;
public String getStudentNumber() {
return studentNumber;
}
public void setStudentNumber(String studentNumber) {
this.studentNumber = studentNumber;
}
}
class FirstYear extends Student {
public void displayAnnouncement() {
System.out.println("Welcome first year student!");
}
}
class SecondYear extends Student {
public void displayAnnouncement() {
System.out.println("Welcome second year student!");
}
}
class ThirdYear extends Student {
public void displayAnnouncement() {
System.out.println("Welcome third year student!");
}
}
public class Main {
public static void main(String[] args) {
FirstYear firstYearStudent = new FirstYear();
firstYearStudent.setStudentNumber("111");
firstYearStudent.displayAnnouncement();
System.out.println("Student Number: " + firstYearStudent.getStudentNumber());
SecondYear secondYearStudent = new SecondYear();
secondYearStudent.setStudentNumber("222");
secondYearStudent.displayAnnouncement();
System.out.println("Student Number: " + secondYearStudent.getStudentNumber());
ThirdYear thirdYearStudent = new ThirdYear();
thirdYearStudent.setStudentNumber("333");
thirdYearStudent.displayAnnouncement();
System.out.println("Student Number: " + thirdYearStudent.getStudentNumber());
}
}
```
In this program, we have an abstract class called "Student" that contains a private variable called "studentNumber". It also has a getter and setter method for accessing and modifying the value of the student number.
We then create three child classes: "FirstYear", "SecondYear", and "ThirdYear", which inherit from the abstract class "Student". Each child class also has a unique method called "displayAnnouncement" that displays a distinct announcement for first years, second years, and third years respectively.
In the main method, we create objects of each child class and set their respective student numbers using the set method. We then call the "displayAnnouncement" method for each object to display the corresponding announcement. Finally, we use the get method to retrieve and print the student number for each object.
I hope this helps! Let me know if you have any further questions.