OO Programming with Java

b. interact with the DB

mkdir sqlusers
cat > sqlusers/UsersDB2.java << EOF
package sqlusers;

import java.sql.*;
import java.util.*;

public class UsersDB2 {
  record User(String name, int mark) {}
  //public static void main(String[] args) {
  public static List<User> getUsers() {
    Connection c=null;
    try { 
      String path="jdbc:sqlite:users.db";
      c=DriverManager.getConnection(path);
      String q="select * from Users";
      Statement s=c.createStatement();
      ResultSet r=s.executeQuery(q);
      List<User> us = new ArrayList<User>();
      while (r.next()) {
        us.add(new User(r.getString("name"),r.getInt("mark")));
      }
      //System.out.println(us);
      return us;
    } catch (Exception e) {
      e.printStackTrace();
      return null;
    } finally {
      try {
        if (c!=null) c.close();
      } catch (Exception e) {
        e.printStackTrace();
      }
    }
  }
  public static void main(String[] args) {
    System.out.println(UsersDB2.getUsers());
  }
}
EOF