Trieda HelloServlet vypisujúca jednoduchý string "Ahoj, svet!".
package aiz; import javax.servlet.*; import javax.servlet.http.*; import java.io.PrintWriter; public class FirstServlet extends HttpServlet { protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, java.io.IOException { PrintWriter out = resp.getWriter(); out.println("Ahoj, svet!"); } }
init(..) | vykonávaná pri načítavaní servletu serverom |
doGet(..) | na spracovanie údajov odoslaných cez HTTP GET -- implicitná HTTP metóda |
doPost(..) | na spracovanie údajov odoslaných cez HTTP POST |
resp.setContentType("text/html; charset=windows-1250");
package aiz; import javax.servlet.*; import javax.servlet.http.*; import java.io.PrintWriter; public class FirstServlet extends HttpServlet { protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, java.io.IOException { resp.setContentType("text/html; charset=windows-1250"); PrintWriter out = resp.getWriter(); out.println("<i>Ľahtikársky kôň v húští <u>mäkkučko</u> úpel <b>matiné</b> ťaživých ód!</i>"); } }
<html> <head> <META http-equiv="Content-Type" content="text/html; charset=windows-1250"> </head> <body> <table width=100% height=100%> <tr> <td align=center valign=middle> <form action="/sps/servlet/aiz.LoginServlet" method="GET"> Prihlasovacie meno: <input type="text" name="username"><br> Heslo: <input type="password" name="password" ><br> <br> <input type="submit" name="submit" value="Prihlásiť"> </form> </td> </tr> </table> </body> </html>
package aiz; import javax.servlet.*; import javax.servlet.http.*; import java.io.PrintWriter; import java.util.Enumeration; public class FormServlet extends HttpServlet { protected String decodeParameter(String parameter) { try { return new String(parameter.getBytes("ISO-8859-1"), "windows-1250"); } catch (Exception e) { return parameter; } } protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, java.io.IOException { resp.setContentType("text/html; charset=windows-1250"); PrintWriter out = resp.getWriter(); out.println("<ul>"); /* metóda getParameterNames() vráti názvy jednotlivých / parametrov, ktoré boli odovzdané metódou GET. */ for(Enumeration e = req.getParameterNames(); e.hasMoreElements(); ) { String parameterName = (String) e.nextElement(); /* metóda getParameterName(String name) vráti hodnotu parametra s názvom name, alebo null, ak taký parameter neexistuje. */ String parameterValue = decodeParameter(req.getParameter(parameterName)); out.println("<li>" + parameterName + " = " + parameterValue + "</li>"); } out.println("</ul>"); } protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, java.io.IOException { } }
<input type="typOvládaciehoPrvku" name="názovOvládaciehoPrvku">
String hodnota = (String)req.getParameter(String názovOvládaciehoPrvku)
String hodnota = new String(hodnota.getBytes("ISO-8859-1"), "windows-1250");