ping i spis treści

PC22-Serwlety/src/main/java/serwlety/Ping.java

+package serwlety;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.PrintWriter;
+import java.time.LocalTime;
+import java.util.Arrays;
+import java.util.Enumeration;
+import java.util.Map;
+
+import jakarta.servlet.ServletException;
+import jakarta.servlet.annotation.WebServlet;
+import jakarta.servlet.http.Cookie;
+import jakarta.servlet.http.HttpServlet;
+import jakarta.servlet.http.HttpServletRequest;
+import jakarta.servlet.http.HttpServletResponse;
+
+@WebServlet("/ping")
+public class Ping extends HttpServlet {
+    private static final long serialVersionUID = 1L;
+       
+    public Ping() {
+        System.out.println("Powstaje obiekt serwletu");
+    }
+    
+    @Override
+    public void init() {
+        System.out.println("init");
+    }
+    
+    @Override
+    public void destroy() {
+        System.out.println("destroy");
+    }
+
+    @Override
+    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
+        /* Gdy uruchamiamy / wgrywamy aplikację, serwer tworzy obiekt tej klasy (serwletu, np. Ping).
+         * Gdy przychodzi zapytanie HTTP typu GET skierowane pod adres tego serwletu (np. /Ping),
+         * serwer wywołuje metodę doGet i w obiekcie request przekazuje nam informację o zapytaniu (adres, parametry, w przypadku metody POST także treść),
+         * natomiast obiekt response dostajemy po to, aby za jego pomocą wygenerować odpowiedź.
+         */
+        String dt = LocalTime.now().toString();
+        String addr = request.getRemoteAddr();
+        int port = request.getRemotePort();
+        String userAgent = request.getHeader("User-Agent");
+
+        System.out.println(dt + ": zapytanie z adresu " + addr + ":" + port + "\nz przeglądarki " + userAgent);
+
+        response.setContentType("text/plain");
+        response.setCharacterEncoding("UTF-8");
+        response.addCookie(new Cookie("czas", dt));
+
+        PrintWriter out = response.getWriter();
+        out.println("Halo halo, GET");
+
+        out.println("ContextPath: " + request.getContextPath());
+        out.println("RequestURI: " + request.getRequestURI());
+        out.println("QueryString: " + request.getQueryString());
+
+        out.println();
+        out.println("LocalName: " + request.getLocalName());
+        out.println("LocalAddr: " + request.getLocalAddr());
+        out.println("LocalPort: " + request.getLocalPort());
+        out.println();
+        out.println("RemoteHost: " + request.getRemoteHost());
+        out.println("RemoteAddr: " + request.getRemoteAddr() + ":" + request.getRemotePort());
+        // itd.
+
+        out.println();
+        out.println("parametr x: " + request.getParameter("x"));
+        out.println("parametr y: " + request.getParameter("y"));
+
+        String[] wartosciX = request.getParameterValues("x");
+        out.println("x jako tablica: " + Arrays.toString(wartosciX));
+
+        out.println("Wszystkie parametry:");
+        for (Map.Entry<String, String[]> e : request.getParameterMap().entrySet()) {
+            String[] v = e.getValue();
+            out.println(" * " + e.getKey() + " : " + Arrays.toString(v));
+        }
+        out.println();
+
+        out.println("nagłówek Accept: " + request.getHeader("Accept"));
+        out.println("nagłówek User-Agent: " + userAgent);
+        out.println("Wszystkie nagłówki:");
+        Enumeration<String> headerNames = request.getHeaderNames();
+        while(headerNames.hasMoreElements()) {
+            String nm = headerNames.nextElement();
+            out.println(nm + ": " + request.getHeader(nm));
+        }
+        out.println();
+
+        out.println("Wszystkie ciastka:");
+        String poprzedniCzas = null;
+        Cookie[] cookies = request.getCookies();
+        if (cookies != null)
+            for (Cookie cooky : cookies) {
+                out.println("cookie " + cooky.getName() + " " + cooky.getValue());
+                if ("czas".equals(cooky.getName())) {
+                    poprzedniCzas = cooky.getValue();
+                }
+            }
+        out.println("czas teraz    : " + dt);
+        out.println("czas poprzedni: " + poprzedniCzas);
+    }
+    
+    @Override
+    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
+        String contentType = request.getHeader("Content-Type");
+        int contentLenght = request.getContentLength();
+        String enc = request.getCharacterEncoding();
+        
+        
+        response.setContentType("text/plain");
+        response.setCharacterEncoding("UTF-8");
+        PrintWriter out = response.getWriter();
+        out.println("Halo halo, POST");
+        out.println("Przyszła treść typu: " + contentType + " , enc: " + enc);
+        out.println("Rozmiar: " + contentLenght);
+        out.println();
+        
+        // dane binarne: request.getInputStream()
+        try(BufferedReader reader = request.getReader()) {
+            out.println("Cały tekst:");
+            String line;
+            while((line = reader.readLine()) != null) {
+                out.println(line);
+            }
+        }
+    }
+
+    @Override
+    protected void doPut(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
+        String contentType = request.getHeader("Content-Type");
+        int contentLenght = request.getContentLength();
+        String enc = request.getCharacterEncoding();
+        
+        response.setContentType("text/plain");
+        response.setCharacterEncoding("UTF-8");
+        PrintWriter out = response.getWriter();
+        out.println("Halo halo, PUT");
+        out.println("Przyszła treść typu: " + contentType + " , enc: " + enc);
+        out.println("Rozmiar: " + contentLenght);
+        out.println();
+        
+        try(BufferedReader reader = request.getReader()) {
+            out.println("Cały tekst:");
+            String line;
+            while((line = reader.readLine()) != null) {
+                out.println(line);
+            }
+        }
+    }
+    
+    @Override
+    protected void doDelete(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
+        response.setContentType("text/plain");
+        response.setCharacterEncoding("UTF-8");
+        PrintWriter out = response.getWriter();
+        out.println("Halo halo, DELETE");
+    }
+
+}

PC22-Serwlety/src/main/webapp/index.html

+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="UTF-8">
+<title>Aplikacja serwletowa</title>
+</head>
+<body>
+<h1>Aplikacja serwletowa – spis treści</h1>
+
+<ul>
+<li><a href="index.html">spis treści</a></li>
+<li><a href="hello">serwlet Hello</a></li>
+<li><a href="ping">ping</a></li>
+<li><a href=""></a></li>
+</ul>
+
+</body>
+</html>
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