Hanukkah of Data 2022: Puzzle 1

package org.example;

import org.sqlite.SQLiteDataSource;

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.time.Duration;
import java.time.Instant;
import java.util.Arrays;

public class Puzzle1 {
  public static void main(String[] args) {
    final var startTime = Instant.now();
    Puzzle1Ter.run();
    final var endTime = Instant.now();
    System.out.println("Duration: " + Duration.between(startTime, endTime).toString());
  }

  private static void run() {
    final var dbUrl = "jdbc:sqlite:/path/to/noahs.sqlite";

    final var dataSource = new SQLiteDataSource();
    dataSource.setUrl(dbUrl);

    final String query = "select name, phone from customers";
    try (final Connection conn = dataSource.getConnection();
         final Statement s = conn.createStatement();
         final ResultSet rs = s.executeQuery(query)) {

      while (rs.next()) {
        final var name = rs.getString("name");
        final var phone = rs.getString("phone");
        final var names = Arrays.asList(name.split(" "));
        // assumption: if only 1 name, that person has no family name, filter it out.
        if (names.size() > 1) {
          // names can have more than 1 element, like James Travis Jr.
          // assumption: last element is always the family name
          // assumption: given name / surname order is always the same
          final var familyName = names.get(names.size() - 1);
          final var computedPhone = Puzzle1.toPhoneNumber(familyName);
          if (computedPhone.equals(phone)) {
            System.out.println("Match found: " + phone);
          }
        }
      }
    } catch (final SQLException e) {
      e.printStackTrace(System.err);
    }
  }

  private static String toPhoneNumber(final String name) {
    final var output = new StringBuilder();
    for (final var c : name.toLowerCase().toCharArray()) {
      // phone number format seems to be xxx-xxx-xxxx
      // so add dashes if there are enough characters in this name
      // improvement: filter out names that would be too short in the first place
      if (output.length() == 3 || output.length() == 7) {
        output.append("-");
      }
      switch (c) {
        case 'a', 'b', 'c' -> output.append("2");
        case 'd', 'e', 'f' -> output.append("3");
        case 'g', 'h', 'i' -> output.append("4");
        case 'j', 'k', 'l' -> output.append("5");
        case 'm', 'n', 'o' -> output.append("6");
        case 'p', 'q', 'r', 's' -> output.append("7");
        case 't', 'u', 'v' -> output.append("8");
        case 'w', 'x', 'y', 'z' -> output.append("9");
        default -> output.append("$");
      }
    }
    return output.toString();
  }
}