Working with Lambda and JDBC

public <T> List<T> getAll(String sql, Function<ResultSet,T> function) {

        final List<T> list = new ArrayList<>();

        try (Connection con = getConeccion()) {

            try (Statement stmt = con.createStatement()) {

                try (ResultSet rs = stmt.executeQuery(sql)) {

                    while (rs.next()) {

                        list.add(function.apply(rs));

                    }

                }

            }

        } catch (SQLException ex) {

             Logger.getLogger(getClass().getName()).log(Level.SEVERE, null, ex);

        }

        return list;

    }

This is a  generic simple solution for querying to database using JDBC.

And we can use the above snippet in this way:

public List<Country> getAllCountries() {

        return getAll("select * from petcare.country", new Function<ResultSet, Country>() {

            @Override

            public Country apply(ResultSet rs) {

                Country c = new Country();

              

                try {

                  

                    c.setId(rs.getInt("id"));

                    c.setName(rs.getString("name"));

                  

                } catch (SQLException ex) {

                    Logger.getLogger(getClass().class.getName()).log(Level.SEVERE, null, ex);

                }

                return c;

            }

        });

    }