Ajuda com Servlet

import javax.servlet.http.*;
import javax.servlet.*;
import java.util.*;
import java.io.*;
import java.sql.*;

public class InsertDate extends HttpServlet{
	public void doPost (HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException{
		String data = request.getParameter("data");
		boolean teste = insertInDataBase(data);
		response.setContentType("text/plain");
		PrintWriter out = response.getWriter();
		if(teste){
			out.println("Executou");
		}
		else{
		     out.println("Não executou");
		}
		out.println("Foi mandado o valor " + data);
		out.close();
	}

	public boolean insertInDataBase(String data){
		Connection con = null;
		
		try{
      		//aqui vai a configuração do driver do BD      
      		Class.forName("org.postgresql.Driver");  
      		con = DriverManager.getConnection("jdbc:postgresql://localhost:5432/postgres", "user", "password");
		Statement stmt = con.createStatement();
		stmt.executeQuery("INSERT INTO TestPost VALUES('data');");
		}
		catch(Exception e){
			return false;
		}
		return true;
	}
}