comparable interface java

1class Student implements Comparable<Student>{  
2int rollno;  
3String name;  
4int age;  
5Student(int rollno,String name,int age){  
6this.rollno=rollno;  
7this.name=name;  
8this.age=age;  
9}  
10  
11public int compareTo(Student st){  
12if(age==st.age)  
13return 0;  
14else if(age>st.age)  
15return 1;  
16else  
17return -1;  
18}  
19}  

1public class BinarySearchTree< T extends Comparable<T>> {
2    Node root;
3    class Node {
4        T data;
5        Node left;
6        Node right;
7
8        public Node(T data) {
9            this.data = data;
10        }
11    }
12
13    public boolean isEmpty() {
14        return root == null;
15    }
16
17    public void insert(T value) {
18        if(isEmpty())
19            root = new Node(value);
20        else
21            insert(root, value);
22    }
23
24    private void insert(Node node, T value) {
25
26        if(value.compareTo(node.data) < 0) {
27            if(node.left == null)
28                node.left = new Node(value);
29            else
30                insert(node.left, value);
31        }
32        else {
33            if(node.right == null)
34                node.right = new Node(value);
35            else
36                insert(node.right, value);
37        }
38    }
39
40}
41