puto jolu

package consultaPostgresqlJavaGuillermo;

import java.beans.Statement;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;

public class Main {

	public static void main(String[] args) {

		try {

			Class.forName("org.postgresql.Driver");
			Connection c = DriverManager.getConnection("jdbc:postgresql://localhost:5432/pruebasql", "postgres", "postgres");


			mostrarNotas(c);


			c.close();

		} catch (Exception e) {
			e.printStackTrace();
			System.err.println(e.getClass().getName() + ": " + e.getMessage());
			System.exit(0);
		}

	}

	private static void mostrarNotas(Connection c) throws SQLException {

		Statement stmt = (Statement) c.createStatement();
        ResultSet rs = ((java.sql.Statement) stmt).executeQuery( "SELECT * FROM alumnos;" );
        while ( rs.next() ) {

        	int id = rs.getInt("id");
           String  nombre = rs.getString("nombre");


           System.out.println( "Id: " + id );
           System.out.println( "Nombre: " + nombre );


        }
        rs.close();

	}
}