/* * @(#)EchoSurvey.java * * Copyright (c) 1998 Karl Moss. All Rights Reserved. * * You may study, use, modify, and distribute this software for any * purpose provided that this copyright notice appears in all copies. * * This software is provided WITHOUT WARRANTY either expressed or * implied. * * @author Karl Moss * @version 1.0 * @date 26Mar98 * */ package javaservlets.samples; import javax.servlet.*; import javax.servlet.http.*; /** *

This is a simple servlet that will echo survey information * that was entered into an HTML form. */ public class EchoSurvey extends HttpServlet { /** *

Performs the HTTP POST operation * * @param req The request from the client * @param resp The response from the servlet */ public void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, java.io.IOException { // Set the content type of the response resp.setContentType("text/html"); // Create a PrintWriter to write the response java.io.PrintWriter out = new java.io.PrintWriter(resp.getOutputStream()); // Print a standard header out.println(""); out.println(""); out.println("Survey Complete"); out.println(""); out.println(""); out.println("

Your survey has been processed!"); out.println("


"); out.println("Values were:"); out.println(""); // Get the name String name = req.getParameter("name"); out.println("Name=" + name + "
"); // Get the email address String email = req.getParameter("email"); out.println("Email=" + email + "
"); // Get the age String age = req.getParameter("age"); out.println("Age=" + age + "
"); // Get the operating system. There could be more than one // value String values[] = req.getParameterValues("os"); out.print("Operating Systems="); if (values != null) { for (int i = 0; i < values.length; i++) { if (i > 0) out.print(", "); out.print(values[i]); } } out.println("
"); // Get the 'more information' flag String more = req.getParameter("more"); out.println("More information=" + more + "
"); // Get the comments String comments = req.getParameter("comments"); out.println("Comments:
"); out.println(""); // Comment lines are separated by a carriage return/line feed // pair - convert them to an HTML line break
out.println(toHTML(comments)); out.println(""); out.println(""); // Wrap up out.println(""); out.println(""); out.flush(); } /** *

Initialize the servlet. This is called once when the * servlet is loaded. It is guaranteed to complete before any * requests are made to the servlet * * @param cfg Servlet configuration information */ public void init(ServletConfig cfg) throws ServletException { super.init(cfg); } /** *

Destroy the servlet. This is called once when the servlet * is unloaded. */ public void destroy() { super.destroy(); } /** *

Convert any carriage return/line feed pairs into * an HTML line break command (
) * * @param line Line to convert * @return line converted line */ private String toHTML(String line) { String s = ""; if (line == null) { return null; } // Cache the length of the line int lineLen = line.length(); // Our current position in the source line int curPos = 0; // Loop through the line and find all of the carriage // return characters (0x0D). If found, convert it into // an HTML line break command (
). If the following // character is a line feed (0x0A) throw it away while (true) { // Make sure we don't run off the end of the line if (curPos >= lineLen) { curPos = 0; break; } int index = line.indexOf(0x0D, curPos); // No more characters found if (index == -1) { break; } // Add any data preceding the carriage return if (index > curPos) { s += line.substring(curPos, index); } // Add the line break command s += "
"; // Adjust our position curPos = index + 1; // If the next character is a line feed, skip it if (curPos < lineLen) { if (line.charAt(curPos) == 0x0A) { curPos++; } } } // Be sure to add anything after the last carriage return // found if (curPos > 0) { s += line.substring(curPos); } return s; } }