Interview Question [Java]

InterviewQ1.java

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.TreeMap;
import java.util.Iterator;

public class InterviewQ1 {
	private TreeMap courseMarksMap = new TreeMap();
	private TreeMap courseRankMap = new TreeMap();

	/* Fetch the data */
	public void fetchData() {
		try {
			Class.forName("com.mysql.jdbc.Driver");
			String url = "jdbc:mysql://localhost:3306/db_name";
			Connection con = DriverManager.getConnection(url, "username", "password");
			Statement stmt = con.createStatement();
			ResultSet rs = stmt.executeQuery("SELECT * from course");
			while (rs.next()) {
				String subject = rs.getString("subject");
				Integer marks = rs.getInt("marks");
				Integer rank = rs.getInt("rank");
				courseMarksMap.put(subject, marks);
				courseRankMap.put(subject, rank);
			}
		} catch (SQLException ex) {
			System.out.println(ex.getMessage());
		} catch (ClassNotFoundException ex) {
			System.out.println(ex.getMessage());
		}
	}

	/* Print the data */
	void printData() {
		int totalMarks = 0;
		int totalSubjects = 0;
		int average = 0;
		Iterator subjectIterator = courseMarksMap.keySet().iterator();
		System.out.print("Subject \t ");
		while (subjectIterator.hasNext()) {
			String subject = (String) subjectIterator.next();
			System.out.print(subject + " \t ");
			totalSubjects++;
		}
		System.out.print("Total \t Average");
		System.out.println();
		System.out.print("Marks \t ");
		subjectIterator = courseMarksMap.keySet().iterator();
		while (subjectIterator.hasNext()) {
			String subject = (String) subjectIterator.next();
			Integer marks = (Integer) courseMarksMap.get(subject);
			System.out.print(marks + "\t\t");
			totalMarks += marks;
		}
		average = totalMarks / totalSubjects;
		System.out.print(totalMarks + "\t\t " + average);
		System.out.println();
		System.out.print("Rank\t");
		subjectIterator = courseRankMap.keySet().iterator();
		while (subjectIterator.hasNext()) {
			String subject = (String) subjectIterator.next();
			Integer rank = (Integer) courseRankMap.get(subject);
			System.out.print(rank + "\t\t");
		}
		System.out.println();
	}
}