import java.io.IOException;

import javax.servlet.ServletException;

import javax.servlet.http.*;

import org.eclipse.jetty.server.Server;

import org.eclipse.jetty.servlet.*;

import java.net.URI;

import java.net.URISyntaxException;

import java.sql.*;

public class Main extends HttpServlet {

@Override

protected void doGet(HttpServletRequest req, HttpServletResponse resp)

throws ServletException, IOException {

if (req.getRequestURI().endsWith("/db")) {

showDatabase(req,resp);

} else {

showHome(req,resp);

}

}

private void showHome(HttpServletRequest req, HttpServletResponse resp)

throws ServletException, IOException {

resp.getWriter().print("Hello from Java!");

}

private void showDatabase(HttpServletRequest req, HttpServletResponse resp)

throws ServletException, IOException {

Connection connection = null;

try {

connection = getConnection();

Statement stmt = connection.createStatement();

stmt.executeUpdate("CREATE TABLE IF NOT EXISTS ticks (tick timestamp)");

stmt.executeUpdate("INSERT INTO ticks VALUES (now())");

ResultSet rs = stmt.executeQuery("SELECT tick FROM ticks");

String out = "Hello!\n";

while (rs.next()) {

out += "Read from DB: " + rs.getTimestamp("tick") + "\n";

}

resp.getWriter().print(out);

} catch (Exception e) {

resp.getWriter().print("There was an error: " + e.getMessage());

} finally {

if (connection != null) try{connection.close();} catch(SQLException e){}

}

}

private Connection getConnection() throws URISyntaxException, SQLException {

URI dbUri = new URI(System.getenv("DATABASE_URL"));

String username = dbUri.getUserInfo().split(":")[0];

String password = dbUri.getUserInfo().split(":")[1];

int port = dbUri.getPort();

String dbUrl = "jdbc:postgresql://" + dbUri.getHost() + ":" + port + dbUri.getPath();

return DriverManager.getConnection(dbUrl, username, password);

}

public static void main(String[] args) throws Exception {

Server server = new Server(Integer.valueOf(System.getenv("PORT")));

ServletContextHandler context = new ServletContextHandler(ServletContextHandler.SESSIONS);

context.setContextPath("/");

server.setHandler(context);

context.addServlet(new ServletHolder(new Main()),"/*");

server.start();

server.join();

}

}