How do I get servlet request URL information?

package org.kodejava.example.servlet;

import java.io.IOException;

import javax.servlet.Servlet;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class ServletUrlInformation extends HttpServlet implements Servlet {
    protected void doGet(HttpServletRequest request,
            HttpServletResponse response) throws ServletException, IOException {
        doPost(request, response);
    }

    protected void doPost(HttpServletRequest request,
            HttpServletResponse response) throws ServletException, IOException {
        //
        // Getting servlet request URL
        //
        String url = request.getRequestURL().toString();

        //
        // Getting servlet request query string.
        //
        String queryString = request.getQueryString();

        //
        // Getting request information without the hostname.
        //
        String uri = request.getRequestURI();

        //
        // Below we extract information about the request object path
        // information. We extract the protocol user, server and and its
        // assigned port number. We extract our application context path,
        // servlet path, path info and the query string information. If we
        // combaine all the information below we'll get someting equals to
        // the request.getRequestURL().
        //
        String scheme = request.getScheme();
        String serverName = request.getServerName();
        int portNumber = request.getServerPort();
        String contextPath = request.getContextPath();
        String servletPath = request.getServletPath();
        String pathInfo = request.getPathInfo();
        String query = request.getQueryString();
    }
}

Source : kodejava.org