src/main/java/io/github/kandefromparis/khool/tomcat/kube/BasicServlet.java

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package io.github.kandefromparis.khool.tomcat.kube;

import java.io.IOException;
import java.io.PrintWriter;
import java.net.InetAddress;
import java.util.Date;
import java.util.Enumeration;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

/**
 * This Servlet inspired from the default tomcat examples display session parameters and hostname
 * @author KanedaFromParis
 */
public class BasicServlet extends HttpServlet {

    /**
     * Processes requests for both HTTP <code>GET</code> and <code>POST</code>
     * methods.
     *
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    protected void processRequest(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        response.setContentType("text/html;charset=UTF-8");
        try (PrintWriter out = response.getWriter()) {
            response.setContentType("text/html");

            HttpSession session = request.getSession(true);

            Date created = new Date(session.getCreationTime());
            Date accessed = new Date(session.getLastAccessedTime());
            String hostName = InetAddress.getLocalHost().getHostName();

            StringBuilder sb = new StringBuilder();
            sb.append("<html><head>\n"
                    + "<meta charset=\"UTF-8\">\n"
                    + "<title>Sessions Example</title>\n"
                    + "</head><body bgcolor=\"white\">\n"
                    + "<h3>Sessions Example</h3>\n"
                    + "Session ID: "+session.getId()+"<br />\n"
                    + "HostName: <b>"+hostName.toString()+"</b><br />\n"
                    + "Created: "+created.toString()+" <br />\n"
                    + "Last Accessed: "+accessed.toString()+" <br />\n")
                    .append("<p>The following data is in your session:<br /></p><p></p><form action=\"BasicServlet\" method=\"POST\">Name of Session Attribute:<input type=\"text\" size=\"20\" name=\"dataname\"><br />Value of Session Attribute:<input type=\"text\" size=\"20\" name=\"datavalue\"><br /><input type=\"submit\"></form><p>GET based form:<br /> </p><form action=\"BasicServlet\" method=\"GET\">Name of Session Attribute:<input type=\"text\" size=\"20\" name=\"dataname\"><br />Value of Session Attribute:<input type=\"text\" size=\"20\" name=\"datavalue\"><br /><input type=\"submit\"></form><p><a href=\"BasicServlet?dataname=foo&amp;datavalue=bar\">URL encoded </a></p></body>");


            // set session info if needed
            String dataName = request.getParameter("dataname");
            if (dataName != null && dataName.length() > 0) {
                String dataValue = request.getParameter("datavalue");
                session.setAttribute(dataName, dataValue);
            }
            sb.append("<hr />");
            sb.append("<p>");
            Enumeration e = session.getAttributeNames();
            while (e.hasMoreElements()) {
                String name = (String) e.nextElement();
                String value = session.getAttribute(name).toString();
                
                sb.append(name).append(" = ").append(value).append("<br />");
            }
            sb.append("</p>");
            sb.append("<hr />");
            out.println(sb.toString());
            out.println("</body></html>");
        }
    }

    // <editor-fold defaultstate="collapsed" desc="HttpServlet methods. Click on the + sign on the left to edit the code.">
    /**
     * Handles the HTTP <code>GET</code> method.
     *
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        processRequest(request, response);
    }

    /**
     * Handles the HTTP <code>POST</code> method.
     *
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        processRequest(request, response);
    }

    /**
     * Returns a short description of the servlet.
     *
     * @return a String containing servlet description
     */
    @Override
    public String getServletInfo() {
        return "Short description";
    }// </editor-fold>

}