Can I get some help finishing the implementations in the comments of this code including the getters and setters for each class as well.. In Java please:

class Student $\{$

private int studentId;

private ArrayList listOfCrns;

public Student$($int studentId$)\{$

this.studentId $=$ studentId;

this.listOfCrns $=$ new ArrayList$<>()$;

$\}$

$//$ Setters and getters for studentId, studentName, and gpa

public void addCourse$($int crn$)\{$

listOfCrns.add$($crn$)$;

$\}$

public void deleteCourse$($int crn$)\{$

listOfCrns.remove$($Integer$.$valueOf$($crn$))$;

$\}$

private double calculateTotalPayment$()\{$

$//$ Implement the calculation based on the given formula

return $0\mathrm{.}0$; $//$ Placeholder, replace with the actual calculation

$\}$

public void printInvoice$()\{$

$//$ Implement the printing of the fee invoice based on the given format

$//$ Use calculateTotalPayment$()$ to get the total amount

$\}$

$\}$

class College $\{$

private ArrayList list;

public College$()\{$

this.list $=$ new ArrayList$<>()$;

$\}$

public void enrollStudent$($Student student$)\{$

$//$ Implement adding a student to the list

$\}$

public boolean searchById$($int studentId$)\{$

$//$ Implement searching for a student by id

return false; $//$ Placeholder, replace with the actual implementation

$\}$

public void addCourse$($int studentId, int crn$)\{$

$//$ Implement adding a course to the student's list of courses

$\}$

public boolean deleteCourse$($int studentId, int crn$)\{$

$//$ Implement deleting a course from the student's list of courses

return false; $//$ Placeholder, replace with the actual implementation

$\}$

public void printInvoice$($int studentId$)\{$

$//$ Implement printing the fee invoice for the student

$\}$

public void printSortedInvoice$($int studentId$)\{$

$//$ Implement printing the fee invoice, sorted by course number, for the student

$//$ Do not sort the private field listOfCrns of the Student class

$\}$