![[j2ee tiers]](Fig4.jpg)
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class SimpleServlet extends HttpServlet
{
public void doGet (HttpServletRequest request,
HttpServletResponse response)
throws ServletException, IOException {
PrintWriter out;
response.setContentType("text/html");
out = response.getWriter();
out.println("<HTML><HEAD><TITLE>");
out.println("Hello world servlet");
out.println("</TITLE></HEAD><BODY>");
out.println("<H1>" + title + "</H1>");
out.println("<P>This is output from SimpleServlet.");
out.println("</BODY></HTML>");
out.close();
}
}
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![[j2ee containters]](Fig5.jpg)
<html>
<head><title>Formularz</title></head>
<body>
<form action="/karolb/test" method="post">
Podaj tekst: <input type="text" name="tekst" value="">
</form>
</body>
</html> |
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class TestServlet extends HttpServlet {
public void doPost(HttpServletRequest request,
HttpServletResponse response)
throws ServletException, IOException {
PrintWriter out;
String tekst;
response.setContentType("text/html");
out = response.getWriter();
out.println("<HTML><HEAD><TITLE>Wyniki z formularza");
out.println("</TITLE></HEAD><BODY>");
tekst = request.getParameter("tekst");
if (tekst != null)
out.println("Z formularza otrzymalem: " + tekst);
else
out.println("Brak danych z formularza");
out.println("</BODY></HTML>");
out.close();
}
public void doGet(HttpServletRequest request,
HttpServletResponse response)
throws ServletException, IOException {
PrintWriter out;
String tekst;
response.setContentType("text/html");
out = response.getWriter();
out.println("<HTML><HEAD><TITLE>Uwaga</TITLE>");
out.println("</HEAD><BODY>");
out.println("Ten serwlet nie obsluguje metody GET!");
out.println("</BODY></HTML>");
out.close();
}
}
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String wartosc = "abc";
out.println("Link do drugiego serwletu z parametrem: " + ...
"<a href=\"" +
response.encodeURL("/drugi_serwlet?param=" + wartosc) + "\">" + ...);
|
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class DodajProdukt extends HttpServlet {
public void doGet(HttpServletRequest request,
HttpServletResponse response)
throws ServletException, IOException {
HttpSession session = request.getSession(true);
Koszyk koszyk =
(Koszyk) session.getAttribute("pl.zakupy.koszyk");
if (koszyk == null) {
koszyk = new Koszyk();
session.setAttribute("pl.zakupy.koszyk", koszyk);
}
koszyk.dodaj(request.getParameter("produkt"));
RequestDispatcher dispatcher =
getServletContext().getRequestDispatcher(
"/wyswietl_koszyk.jsp");
if (dispatcher != null)
dispatcher.forward(request, response);
}
}
|
String wartosc = "byle-co";
Cookie ciacho = new Cookie("Nazwa", wartosc);
response.addCookie(ciacho);
|
Cookie[] cookies = request.getCookies();
String wartosc;
for (int i = 0; i < cookies.length; i++) {
if (cookies[i].getName().equals("Nazwa"))
wartosc = thisCookie.getValue();
}
|
public class WyswietlDane extends HttpServlet {
public synchronized void init() throws ServletExcpetion {
BazaDanych bd = (BazaDanych)
getServletContext().getAttribute("pl.sklep.bd.baza");
if (bd == null) {
bd = new BazaDanych("http://pulsar", "scott", "tiger");
getServletContext().setAttribute("pl.sklep.bd.baza", bd);
}
}
...
}
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public final class HitCounterFilter implements Filter {
private FilterConfig filterConfig = null;
public void init(FilterConfig filterConfig)
throws ServletException {
this.filterConfig = filterConfig;
}
public void destroy() {
this.filterConfig = null;
}
public void doFilter(ServletRequest request,
ServletResponse response, FilterChain chain)
throws IOException, ServletException {
if (filterConfig == null)
return;
StringWriter sw = new StringWriter();
PrintWriter writer = new PrintWriter(sw);
Counter counter = (Counter)filterConfig.
getServletContext().
getAttribute("hitCounter");
writer.println();
writer.println("===============");
writer.println("The number of hits is: " +
counter.incCounter());
writer.println("===============");
// Log the resulting string
writer.flush();
filterConfig.getServletContext().
log(sw.getBuffer().toString());
...
chain.doFilter(request, wrapper);
...
}
}
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<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE web-app
PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.2//EN"
"http://java.sun.com/j2ee/dtds/web-app_2_2.dtd">
<web-app>
<servlet>
<servlet-name>
test_serw
</servlet-name>
<servlet-class>
Test
</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>
test_serw
</servlet-name>
<url-pattern>
/test
</url-pattern>
</servlet-mapping>
</web-app>
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<Context path="/test_kat"
docBase="webapps/test_kat"
reloadable="true"/>
|