This means that your clients.db file was not found. Try to find this file in a more appropriate way. Scroll to the "How to specify database files" section.
I downloaded the SQLite JAR, put it in my CLASSPATH, and found a tutorial here that worked great in less than five minutes. He put test.db at the root of my project, as expected.
I rewrote this tutorial the way I did it. It is working. Do not say that it does not bring anything.
package sqlite; import java.sql.Connection; import java.sql.DriverManager; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; import java.util.ArrayList; import java.util.List; public class Test { private static final String DEFAULT_DRIVER = "org.sqlite.JDBC"; private static final String DEFAULT_URL = "jdbc:sqlite:data/test.db"; public static void main(String[] args) { Connection conn = null; try { conn = createConnection(DEFAULT_DRIVER, DEFAULT_URL); createTable(conn); List<Person> people = new ArrayList<Person>(); people.add(new Person("Gandhi", "politics")); people.add(new Person("Wittgenstein", "philosophy")); people.add(new Person("Turing", "computers")); saveAll(conn, people); List<Person> rows = findAll(conn); System.out.println(rows); } catch (ClassNotFoundException e) { e.printStackTrace(); } catch (SQLException e) { e.printStackTrace(); } finally { close(conn); } } private static List<Person> findAll(Connection conn) throws SQLException { List<Person> rows = new ArrayList<Person>(); ResultSet rs = null; Statement stat = null; try { stat = conn.createStatement(); rs = stat.executeQuery("select * from people;"); while (rs.next()) { rows.add(new Person(rs.getString("name"), rs.getString("occupation"))); } } finally { close(stat); close(rs); } return rows; } private static void saveAll(Connection conn, List<Person> people) throws SQLException { PreparedStatement prep = null; try { prep = conn.prepareStatement("insert into people values (?, ?);"); for (Person person : people) { prep.setString(1, person.getName()); prep.setString(2, person.getOccupation()); prep.addBatch(); } conn.setAutoCommit(false); prep.executeBatch(); conn.setAutoCommit(true); } finally { close(prep); } } private static void createTable(Connection conn) throws SQLException { Statement stat = null; try { stat = conn.createStatement(); stat.executeUpdate("drop table if exists people;"); stat.executeUpdate("create table people (name, occupation);"); } finally { close(stat); } } private static Connection createConnection(String driver, String url) throws ClassNotFoundException, SQLException { Class.forName(DEFAULT_DRIVER); Connection conn = DriverManager.getConnection(DEFAULT_URL); return conn; } private static void close(Connection conn) { try { if (conn != null) { conn.close(); } } catch (Exception e) { e.printStackTrace(); } } private static void close(Statement stat) { try { if (stat != null) { stat.close(); } } catch (Exception e) { e.printStackTrace(); } } private static void close(ResultSet rs) { try { if (rs != null) { rs.close(); } } catch (Exception e) { e.printStackTrace(); } } } class Person { private String name; private String occupation; Person(String name, String occupation) { this.name = name; this.occupation = occupation; } public String getName() { return this.name; } public String getOccupation() { return this.occupation; } public String toString() { StringBuilder sb = new StringBuilder(); sb.append("{ name: ").append(this.name).append(", occupation: ").append(this.occupation).append(" }"); return sb.toString(); } }