三个servlet的实现:
package app02c;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
* Cookies的实现(设置cookie)
*/
@WebServlet( name = "PreferenceServlet", urlPatterns = "/preference")
public class PreferenceServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
// 主菜单
public static final String MENU =
"<div style='background:#e8e8e8;"
+ "padding:15px'>"
+ "<a href='cookieClass'>Cookie Class</a> "
+ "<a href='cookieInfo'>Cookie Info</a> "
+ "<a href='preference'>Preference</a>" + "</div>";
/**
* @see HttpServlet#HttpServlet()
*/
public PreferenceServlet() {
super();
// TODO Auto-generated constructor stub
}
/**
* 主页的选择
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
response.setContentType("text/html");
PrintWriter writer = response.getWriter();
writer.print("<html><head>" + "<title>Preference</title>"
+ "<style>table {" + "font-size:small;"
+ "background:NavajoWhite }</style>"
+ "</head><body>"
+ MENU
+ "Please select the values below:"
+ "<form method='post'>"
+ "<table>"
+ "<tr><td>Title Font Size: </td>"
+ "<td><select name='titleFontSize'>"
+ "<option>large</option>"
+ "<option>x-large</option>"
+ "<option>xx-large</option>"
+ "</select></td>"
+ "</tr>"
+ "<tr><td>Title Style & Weight: </td>"
+"<td><select name='titleStyleAndWeight' multiple>"
+ "<option>italic</option>"
+ "<option>bold</option>"
+ "</select></td>"
+ "</tr>"
+ "<tr><td>Max. Records in Table: </td>"
+ "<td><select name='maxRecords'>"
+ "<option>5</option>"
+ "<option>10</option>"
+ "</select></td>"
+ "</tr>"
+ "<tr><td rowspan='2'>"
+ "<input type='submit' value='Set'/></td>"
+ "</tr>"
+ "</table>" + "</form>" + "</body></html>");
}
/**
* 设置cookie
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String maxRecords = request.getParameter("maxRecords");
// 下拉列表multiple属性的获取方式
String[] titleStyleAndWeight = request
.getParameterValues("titleStyleAndWeight");
String titleFontSize =
request.getParameter("titleFontSize");
// 设置cookie
response.addCookie(new Cookie("maxRecords", maxRecords));
response.addCookie(new Cookie("titleFontSize",
titleFontSize));
// delete titleFontWeight and titleFontStyle cookies first
// Delete cookie by adding a cookie with the maxAge = 0;
Cookie cookie = new Cookie("titleFontWeight", "");
cookie.setMaxAge(0);
response.addCookie(cookie);
cookie = new Cookie("titleFontStyle", "");
cookie.setMaxAge(0);
response.addCookie(cookie);
if (titleStyleAndWeight != null) {
for (String style : titleStyleAndWeight) {
if (style.equals("bold")) {
// 添加cookie
response.addCookie(new
Cookie("titleFontWeight", "bold"));
} else if (style.equals("italic")) {
response.addCookie(new Cookie("titleFontStyle",
"italic"));
}
}
}
response.setContentType("text/html");
PrintWriter writer = response.getWriter();
writer.println("<html><head>" + "<title>Preference</title>"
+ "</head><body>" + MENU
+ "Your preference has been set."
+ "<br/><br/>Max. Records in Table: " + maxRecords
+ "<br/>Title Font Size: " + titleFontSize
+ "<br/>Title Font Style & Weight: ");
// titleStyleAndWeight will be null if none of the options
// was selected
if (titleStyleAndWeight != null) {
writer.println("<ul>");
for (String style : titleStyleAndWeight) {
writer.print("<li>" + style + "</li>");
}
writer.println("</ul>");
}
writer.println("</body></html>");
}
}
package app02c;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
* 显示数据,根据接受的cookie来选择输出数量
*/
@WebServlet( name = "CookieClassServlet", urlPatterns = "/cookieClass")
public class CookieClassServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
// 设置显示的数据
private String[] methods = {
"clone", "getComment", "getDomain",
"getMaxAge", "getName", "getPath",
"getSecure", "getValue", "getVersion",
"isHttpOnly", "setComment", "setDomain",
"setHttpOnly", "setMaxAge", "setPath",
"setSecure", "setValue", "setVersion"
};
/**
* @see HttpServlet#HttpServlet()
*/
public CookieClassServlet() {
super();
// TODO Auto-generated constructor stub
}
/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// 获取cookie
Cookie[] cookies = request.getCookies();
Cookie maxRecordsCookie = null;
if (cookies != null) {
// 遍历cookie
for (Cookie cookie : cookies) {
if (cookie.getName().equals("maxRecords")) {
maxRecordsCookie = cookie;
break;
}
}
}
int maxRecords = 5; // default
if (maxRecordsCookie != null) {
try {
maxRecords = Integer.parseInt(
maxRecordsCookie.getValue());
} catch (NumberFormatException e) {
// do nothing, use maxRecords default value
}
}
response.setContentType("text/html");
PrintWriter writer = response.getWriter();
writer.print("<html><head>" + "<title>Cookie Class</title>"
+ "</head><body>"
+ PreferenceServlet.MENU
+ "<div>Here are some of the methods in " +
"javax.servlet.http.Cookie");
writer.print("<ul>");
for (int i = 0; i < maxRecords; i++) {
writer.print("<li>" + methods[i] + "</li>");
}
writer.print("</ul>");
writer.print("</div></body></html>");
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
doGet(request, response);
}
}
package app02c;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
* 根据接受到cookie来显示详细信息
*/
@WebServlet(name = "CookieInfoServlet", urlPatterns = "/cookieInfo")
public class CookieInfoServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
/**
* @see HttpServlet#HttpServlet()
*/
public CookieInfoServlet() {
super();
// TODO Auto-generated constructor stub
}
/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
Cookie[] cookies = request.getCookies();
StringBuilder styles = new StringBuilder();
// 设置修饰
styles.append(".title {");
if (cookies != null) {
// 根据设置的cookie显示
for (Cookie cookie : cookies) {
String name = cookie.getName();
String value = cookie.getValue();
if (name.equals("titleFontSize")) {
styles.append("font-size:" + value + ";");
} else if (name.equals("titleFontWeight")) {
styles.append("font-weight:" + value + ";");
} else if (name.equals("titleFontStyle")) {
styles.append("font-style:" + value + ";");
}
}
}
styles.append("}");
response.setContentType("text/html");
PrintWriter writer = response.getWriter();
writer.print("<html><head>" + "<title>Cookie Info</title>"
+ "<style>" + styles.toString() + "</style>"
+ "</head><body>" + PreferenceServlet.MENU
+ "<div class='title'>"
+ "Session Management with Cookies:</div>");
writer.print("<div>");
// cookies will be null if there's no cookie
if (cookies == null) {
writer.print("No cookie in this HTTP response.");
} else {
writer.println("<br/>Cookies in this HTTP response:");
// 显示cookie
for (Cookie cookie : cookies) {
writer.println("<br/>" + cookie.getName() + ":"
+ cookie.getValue());
}
}
writer.print("</div>");
writer.print("</body></html>");
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
doGet(request, response);
}
}