Java Tutorial/Servlet/URL Rewrite
Servlet Query String
<source lang="java">
import java.io.*; import javax.servlet.*; import javax.servlet.http.*; import java.util.*; public class MyServlet extends HttpServlet {
public void doGet(HttpServletRequest req, HttpServletResponse res) throws ServletException, IOException { res.setContentType("text/plain"); PrintWriter out = res.getWriter(); out.println("Query String:"); out.println(req.getQueryString()); out.println(); out.println("Request Parameters:"); Enumeration e = req.getParameterNames(); while (e.hasMoreElements()) { String name = (String) e.nextElement(); String values[] = req.getParameterValues(name); if (values != null) { for (int i = 0; i < values.length; i++) { out.println(name + " (" + i + "): " + values[i]); } } } }
}</source>
Servlet URL Rewrite
<source lang="java">
import java.io.*; import javax.servlet.*; import javax.servlet.http.*; import java.util.*; public class MyServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, java.io.IOException { response.setContentType("text/html"); java.io.PrintWriter out = response.getWriter(); String contextPath = request.getContextPath(); String encodedUrl = response.encodeURL(contextPath + "/default.jsp"); out.println("<html>"); out.println("<head>"); out.println("<title>URL Rewriter</title>"); out.println("</head>"); out.println("<body>");out.println("
This page will use URL rewriting if necessary</h2>");
out.println("Go to the default.jsp page
URL rewriting
<source lang="java">
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; import javax.servlet.http.HttpSession; public class CounterRewrite extends HttpServlet {
static final String COUNTER_KEY = "Counter.count"; public void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { HttpSession session = req.getSession(true); resp.setContentType("text/html"); PrintWriter out = resp.getWriter(); int count = 1; Integer i = (Integer) session.getAttribute(COUNTER_KEY); if (i != null) { count = i.intValue() + 1; } session.setAttribute(COUNTER_KEY, new Integer(count)); out.println("<html>"); out.println("<head>"); out.println("<title>Session Counter</title>"); out.println("</head>"); out.println("<body>"); out.println("Your session ID is " + session.getId()); out.println(" and you have hit this page " + count + " time(s) during this browser session"); String url = req.getRequestURI(); out.println("<form method=GET action=\"" + resp.encodeURL(url) + "\">"); out.println("<input type=submit " + "value=\"Hit page again\">"); out.println("</form>"); out.println("</body>"); out.println("</html>"); out.flush(); }
}</source>