--> constructror(+UndergraduateStudent -- +Student)

src/model/GraduateStudent.java

@@ -3,11 +3,15 @@
 public class GraduateStudent extends Student {
   private String supervisor;
   private String thesisTitle;
-
   @Override
   public void getStudentDetails() {
     // TODO: Implement method 'getStudentDetails' for GraduateStudent.
     throw new UnsupportedOperationException("Unimplemented method 'getStudentDetails'");
   }
-
+public GraduateStudent(String studentId,String firstName,String lastName,String major,String superString,String theString)
+{
+      super(studentId, firstName, lastName, major);
+      this.supervisor=supervisor;
+      this.thesisTitle=thesisTitle;
+}
 }

src/model/Loan.java

@@ -8,23 +8,10 @@ public class Loan {
   private Date loanDate;
   private Date dueDate;
 
-  public void getBook() {
-    // TODO: Implement method 'getBook'.
-    throw new UnsupportedOperationException("Unimplemented method 'getBook'");
-  }
 
-  public void getStudent() {
-    // TODO: Implement method 'getStudent'.
-    throw new UnsupportedOperationException("Unimplemented method 'getStudent'");
-  }
+  public void getBook     (Book book)          {this.book=book;}
+  public void getStudent  (Student student) {this.student=student;}
+  public void getLoanDate (Date loanDate)  {this.loanDate=loanDate;}
+  public void getDueDate  (Date dueDate)    {this.dueDate=dueDate;}
 
-  public void getLoanDate() {
-    // TODO: Implement method 'getLoanDate'.
-    throw new UnsupportedOperationException("Unimplemented method 'getLoanDate'");
-  }
-
-  public void getDueDate() {
-    // TODO: Implement method 'getDueDate'.
-    throw new UnsupportedOperationException("Unimplemented method 'getDueDate'");
-  }
 }

src/model/Student.java

@@ -1,10 +1,16 @@
 package model;
 
 public abstract class Student {
-  private String studentId;
-  private String firstName;
-  private String lastName;
-  private String major;
-
-  public abstract void getStudentDetails();
+  protected  String studentId;
+  protected  String firstName;
+  protected  String lastName;
+  protected  String major;
+public Student(String studentId,String firstName,String lastName,String major)
+{
+      this.studentId=studentId;
+      this.firstName=firstName;
+      this.lastName=lastName;
+      this.major=major;
 }
+  public abstract void getStudentDetails();
+}

src/model/UndergraduateStudent.java

@@ -8,4 +8,11 @@ public void getStudentDetails() {
     // TODO: Implement method 'getStudentDetails' for UndergraduateStudent.
     throw new UnsupportedOperationException("Unimplemented method 'getStudentDetails'");
   }
+
+    public UndergraduateStudent(String studentId,String firstName,String lastName,String major,int enrollmentYear)
+    {
+        super(studentId,firstName,lastName,major);
+        this.enrollmentYear=enrollmentYear;
+    }
+
 }