convert uml class diagram to java code | Student and Section

public class Student{
    private int StudentId;
    private  String StudentName;
    private int StudentAge;
    
    public Student(int studId,String stuName,int age)
    {
        StudentId=studId;
        StudentName=stuName;
        StudentAge=age;
    }
    public void setStudentId(int s){
        StudentId=s;
    }
    public int getStudentId()
    {
        return StudentId;
    }
    public void setStudentName(String StudentName){
        this.StudentName=StudentName;
    }
    public String getStudentName()
    {
        return StudentName;
    }
    public void setStudentAge(int StudentAge){
        this.StudentAge=StudentAge;
    }
    public int getStudentAge()
    {
        return StudentAge;
    }
}

public class Section{
    private Student arrayStu[];
    private int counter;
    
    public Section(int size)
    {
        arrayStu[]=new Student[size];
        counter=-1;
    }
    public boolean addStudent(Student stu)
    {
        if(counter<size-1) 
        {
            counter++;
        arrayStu[counter].setStudentId(stu.getStudentId());
        arrayStu[counter].setStudentName(stu.getStudentName());
        arrayStu[counter].setStudentAge(stu.getStudentAge());
        return True;
        }
        else //this case happened when counter = size-1
        {
            System.out.println("array of students is full!");
            return false;
        }
    }
    public int searchStudent(int stuid)
    {
        for(int i=0;i<=this.counter;i++)
        {
            if(stuid==arrayStu[i].getStudentId())
            return i;
        }
        return -1;
    }
    public int calculateTotalAges()
    {
        int totalAges=0;
        for(int i=0;i<=this.counter;i++)
        {
            totalAges=totalAges+arrayStu[i].getStudentAge();
        }
        return totalAges;
    }
    public double calculateAvgAge()
    {
        return calculateTotalAges()/(counter+1);
    }
    public void printStuData(int stuid)
    {
        int studentIndex=searchStudent(stuid);
        if(studentIndex==-1)
        System.out.println("the student with id : " + stuid+" is not exsiting!");
        else System.out.println("student name : "+arrayStu[studentIndex].getStudentName+", student age: "+arrayStu[studentIndex].getStudentAge());
    }
    public boolean deleteStu(int stuid)
    {
        int studentIndex=searchStudent(stuid);
        if(studentIndex==-1)
        System.out.println("the student with id : " + stuid+" is not exsiting!");
        else {
        for(int i=studentIndex;i<=this.counter;i++)
        {
            arrayStu[i]=arrayStu[i+1]; //shiftleft
        }
            counter--;// decrease the number of exsiting students
        }
    }
    public int findMaxAge()
    {
        int maxAge=-1;//default value=-1 means that there is no max age at all, because there no students.
        if(counter>-1){
        maxAge=arrayStu[0].getStudentAge();
        for(int i=0;i<=this.counter;i++)
        {
            if(arrayStu[i].getStudentAge()>maxAge)
            maxAge=arrayStu[i];
        }
        return maxAge;
        }
    }
    public int findMinAge()
    {
        int minAge=-1;//default value=-1 means that there is no min age at all, because there no students.
        if(counter>-1){
        minAge=arrayStu[0].getStudentAge();
        for(int i=1;i<=this.counter;i++)
        {
            if(arrayStu[i].getStudentAge()<minAge)
            minAge=arrayStu[i];
        }
        return minAge;       
    }   
}

public class Test
{
	public static void main(String[] args) {
	    Section sec=new Section(10);
	    Student s1=new Student(1,"adnan",15);
	    Student s2=new Student(2,"mohammad",18);
	    Student s3=new Student(3,"jhon",10);
	    Student s4=new Student(4,"george",12);
	    Student s5=new Student(5,"ali",19);
	    sec.addStudent(s1);
	    sec.addStudent(s2);
	    sec.addStudent(s3);
	    sec.addStudent(s4);
	    sec.addStudent(s5);
	    sec.deleteStu(2);
	    System.out.println(sec.findMaxAge());
	    System.out.println(sec.findMinAge());
	}
}