Session:
Session實現原理:
瀏覽器未禁用Cookie:
Jsp代碼：
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>My JSP 'index.jsp' starting page</title>
</head>
<body>
<a href="/day07/servlet/SessionDemo1">購買</a>
<a href="/day07/servlet/SessionDemo2">結賬</a>
</body>
</html>Servlet代碼：
//購買
public class SessionDemo1 extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
//第一次getSession時創建Session，默認30分鐘沒人用Session就自動摧毀了
HttpSession session = request.getSession();
//Session技術是基於Cookie技術實現的，每次創建完Session，都會將JSESSIONID寫給瀏覽器
//但是默認存放JSESSIONID的Cookie有效時間爲0，即關閉瀏覽器Cookie就消失，所以默認情況下，一個瀏覽器獨佔一個Session
//所以電子商務網站必須有以下過程，手動設置存放JSESSIONID的Cookie的有效時間和Session的一致
//即重寫存放JSESSIONID的Cookie,這樣就實現了多瀏覽共享一個Session，即關閉瀏覽器再打開也能得到上次的Session
String sessionid = session.getId();
Cookie cookie = new Cookie("JSESSIONID",sessionid);
cookie.setPath("/day07");
cookie.setMaxAge(30*60);
response.addCookie(cookie);
session.setAttribute("name", "洗衣機");
//不創建只獲取,用於顯示購物車,有人閒的不買直接結賬查看購物車，這時不必創建session
// request.getSession(false);
//invalidate摧毀Session，或者在web.xml裏<session-config>配置摧毀時間
// session.invalidate();
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request, response);
}
}//結賬
public class SessionDemo2 extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setCharacterEncoding("UTF-8");
response.setHeader("content-Type", "text/html;charset=utf-8");
PrintWriter out = response.getWriter();
HttpSession session = request.getSession(false);
String product = (String)session.getAttribute("name");
out.write("您購買的商品是："+product);
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request, response);
}
}Servlet代碼：
//首頁
public class WelcomeServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setCharacterEncoding("UTF-8");
response.setHeader("Content-Type", "text/html;charset=UTF-8");
PrintWriter out = response.getWriter();
//一訪問首頁自動創建Session，getSession首先檢查cookie是否有JSESSIONID，再檢查url後是否有JSESSIONID,如果都沒有則新創建個Session
request.getSession();
//如果禁用了cookie，那麼電子商務使用Session則需要重寫url(但是這種方法卻無法解決關閉瀏覽器再打開後，獲取上一次Session)
//讓用戶點擊超鏈接自動帶上JSESSIONID
//以下兩句實現了Url地址後自動加上JSESSIONID，Sun公司提供的方法
//如果服務器發現用戶沒有禁用cookie，則不會重寫url(第一次訪問服務器既重寫url又返回cookie，第二次訪問，服務器發現有cookie，則url不會帶參數)
String url1 = response.encodeRedirectURL("/day07/servlet/SessionDemo1");
String url2 = response.encodeRedirectURL("/day07/servlet/SessionDemo2");
out.print("<a href='"+url1+"'>購買</a> ");
out.print("<a href='"+url2+"'>結賬</a>");
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request, response);
}
}Session案例——實現簡單的購物:
Servlet代碼：
//商品類（書籍）
class Book{
private String id;
private String name;
private String author;
private String description;
public Book() {
super();
// TODO Auto-generated constructor stub
}
public Book(String id, String name, String author, String description) {
super();
this.id = id;
this.name = name;
this.author = author;
this.description = description;
}
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getAuthor() {
return author;
}
public void setAuthor(String author) {
this.author = author;
}
public String getDescription() {
return description;
}
public void setDescription(String description) {
this.description = description;
}
}
//數據庫(如果有檢索數據需求，則用雙列(Map)，如果不檢索，則用單列(List) )
class Db{
private static Map<String,Book> map = new LinkedHashMap(); //如果用HashMap，則獲取商品順序和存入順序不一致，hashMap是根據hash值排列的
//靜態塊，一使用Db類就自動執行
static{
map.put("1", new Book("1","javaweb開發","老張","一本好書"));
map.put("2", new Book("2","jdbc開發","老張","一本好書"));
map.put("3", new Book("3","spring開發","老黎","一本好書"));
map.put("4", new Book("4","struts開發","老畢","一本好書"));
map.put("5", new Book("5","android開發","老黎","一本好書"));
}
public static Map getAll(){
return map;
}
}//代表網站首頁，列出所有書
public class ListBookServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
//以後學習過濾器filter，設置一次，則所有資源都解決中文亂碼，不必每次都設置
response.setCharacterEncoding("UTF-8");
response.setHeader("Content-Type", "text/html;charset=UTF-8");
PrintWriter out = response.getWriter();
request.getSession();//一訪問首頁就建立session，以防cookie禁用,則用重寫url
out.print("本網站有如下商品：<br/>");
Map<String,Book> map = Db.getAll();
for(Map.Entry<String, Book> entry : map.entrySet()){
Book book = (Book)entry.getValue();
String url = response.encodeRedirectURL(request.getContextPath()+"/servlet/BuyServlet?id="+book.getId());
out.print(book.getName()+" <a href='"+url+"' target='_blank'>購買</a><br/>");
}
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request, response);
}
}//完成購買
public class BuyServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
String id = request.getParameter("id");
Book book = (Book)Db.getAll().get(id);
HttpSession session = request.getSession(false);
//手工以cookie形式發sessionid，來解決關閉瀏覽器後，上次買的東西還在
String sessionid = session.getId();
Cookie cookie = new Cookie("JSESSIONID",sessionid);
cookie.setMaxAge(30*60);
cookie.setPath(request.getContextPath());
response.addCookie(cookie);
//從Session中得到用戶用於保存所有書的集合(得到用戶的購物車)
List list = (List)session.getAttribute("list");
if(list==null){
list = new ArrayList();
session.setAttribute("list", list);
}
list.add(book);
//到結賬界面要用重定向
response.setStatus(302);
//最好不寫死跳轉路徑，用request.getContextPath()得到當前web應用目錄
String url = response.encodeRedirectURL(request.getContextPath()+"/servlet/ListCartServlet");
response.setHeader("Location", url);
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request, response);
}
}//顯示用戶購買的商品
public class ListCartServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setCharacterEncoding("UTF-8");
response.setHeader("content-type", "text/html;charset=UTF-8");
PrintWriter out = response.getWriter();
HttpSession session = request.getSession(false);
if(session==null){
out.print("您沒有購買任何商品!!");
return;
}
out.print("您購買了如下商品：<br/>");
List<Book> list = (List)session.getAttribute("list");
for(Book book : list){
out.print(book.getName()+"<br/>");
}
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request, response);
}
}Session案例——完成用戶的登錄:
html代碼：
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>login.html</title>
</head>
<body>
<form action="/day07/servlet/LoginServlet" method="post">
用戶名：<input type="text" name="username"/><br/>
密碼：<input type="password" name="password"/><br/>
<input type="submit" value="登錄"/>
</form>
</body>
</html>Servlet代碼：
//用戶類
public class User {
private String username;
private String password;
public User() {
super();
// TODO Auto-generated constructor stub
}
public User(String username, String password) {
super();
this.username = username;
this.password = password;
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
}
//數據庫
class DB{
public static List list = new ArrayList();
static{
list.add(new User("aaa","123"));
list.add(new User("bbb","123"));
list.add(new User("ccc","123"));
}
public static List getAll(){
return list;
}
}//完成用戶登錄
public class LoginServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setCharacterEncoding("UTF-8");
response.setHeader("Content-Type", "text/html;charset=UTF-8");
PrintWriter out = response.getWriter();
String username = request.getParameter("username");
String password = request.getParameter("password");
List<User> list = DB.getAll();
for(User user : list){
if(user.getUsername().equals(username)&&user.getPassword().equals(password)){
request.getSession().setAttribute("user", user); //登錄成功，向Session存入一個登錄標記
response.setStatus(302);
response.setHeader("Location", "/day07/index.jsp");
return;
}
}
out.write("用戶名或密碼不對！！");
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request, response);
}
}//完成用戶註銷
public class LogoutServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
HttpSession session = request.getSession(false);
if(session==null){
response.setStatus(302);
response.setHeader("Location", "/day07/index.jsp");
return;
}
session.removeAttribute("user");
response.setStatus(302);
response.setHeader("Location", "/day07/index.jsp");
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request, response);
}
}Jsp代碼：
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>My JSP 'index.jsp' starting page</title>
</head>
<body>
歡迎您：${user.username} <a href="/day07/login.html">登錄</a> <a href="/day07/servlet/LogoutServlet">退出登錄</a>
<br/><br/><br/>
<a href="/day07/servlet/SessionDemo1">購買</a>
<a href="/day07/servlet/SessionDemo2">結賬</a>
</body>
</html>Session案例——防止表單重複提交:
客戶端javascript防止表單重複提交：
html代碼：
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>form.html</title>
<!-- 用js阻止表單重複提交(屬於客戶端阻止重複提交，不安全，用戶可以自己重寫提交頁面或者刷新/後退頁面繼續提交)
但是還是要用客戶端阻止一下，再用服務器阻止-->
<script type="text/javascript">
/*
var iscommitted = false;
function dosubmit(){
if(!iscommitted){
iscommitted=true;
return true;
}
else{
return false;
}
}
*/
function dosubmit(){
var input = document.getElementById("submit");
input.disabled = 'disabled';
return true;
}
</script>
</head>
<body>
<form action="/day07/servlet/DoFormServlet" method="post" οnsubmit="return dosubmit()">
用戶名：<input type="text" name="username"/>
<input id="submit" type="submit" value="提交" />
</form>
</body>
</html>服務器端session防止表單重複提交：
Servlet代碼：
//令牌發生器，爲了保證發生的令牌唯一性（低重複概率），要設計成單類
class TokenProcessor{
/** 單類設計方法：
* 1.把構造方法私有
* 2.自己創建一個實例
* 3.對外暴露一個方法，允許獲取上面創建的對象
*/
private TokenProcessor(){}
private static final TokenProcessor instance = new TokenProcessor();
public static TokenProcessor getInstance(){
return instance;
}
//產生令牌(隨機數)的方法
public String generateToken(){
//爲了隨機數儘可能唯一，令牌裏用 當前毫秒值+隨機數
String token = System.currentTimeMillis() + new Random().nextInt() + "";
try {
//爲了保證隨機數長度固定，需要得到數據指紋(即數據摘要，只有128位（bit）,即16字節(byte))
MessageDigest md = MessageDigest.getInstance("md5");//用md5算法算出數據摘要
byte[] md5 = md.digest(token.getBytes());//得到數據摘要，數組長度始終未16
//base64編碼
BASE64Encoder encoder = new BASE64Encoder();
return encoder.encode(md5);
}
catch (NoSuchAlgorithmException e) {
throw new RuntimeException(e);
}
}
}//產生表單
public class FormServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
//產生一個隨機數(表單號)
TokenProcessor tp = TokenProcessor.getInstance();
String token = tp.generateToken();
//服務器保存一份表單號(token)
request.getSession().setAttribute("token", token);
//轉發到表單頁面
request.getRequestDispatcher("/form.jsp").forward(request, response);
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request, response);
}
}jsp代碼：
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>My JSP 'form.jsp' starting page</title>
</head>
<body>
<form action="/day07/servlet/DoFormServlet" method="post">
<input type="hidden" name="token" value="${token }"/>
用戶名：<input type="text" name="username"/><br/>
<input type="submit" value="提交"/>
</form>
</body>
</html>Servlet代碼：
//處理表單
public class DoFormServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
boolean b = isTokenValid(request);
if(!b){
System.out.println("請不要重複提交!");
return;
}
request.getSession().removeAttribute("token");
System.out.println("處理：向數據庫註冊用戶~~~~");
}
//判斷表單號是否有效
private boolean isTokenValid(HttpServletRequest request) {
//得到客戶端提交表單時帶的token（表單號）
String client_token = request.getParameter("token");
if(client_token==null){ //客戶端未通過程序輸出的表單提交，則不帶token
return false;
}
//得到服務器端session中存放的token(表單號)
String server_token = (String)request.getSession().getAttribute("token");
if(server_token==null){ //服務器端沒有token，表示已經提交過了
return false;
}
if(!client_token.equals(server_token)){ //客戶端帶來的token和服務器端token不一致
return false;
}
return true;
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request, response);
}
}Session案例——校驗圖片認證碼:
Servlet代碼：
//輸出一張隨機圖片
public class ImageServlet extends HttpServlet {
public static final int WIDTH = 120;
public static final int HEIGHT = 35;
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
BufferedImage image = new BufferedImage(WIDTH,HEIGHT,BufferedImage.TYPE_INT_RGB);
Graphics g = image.getGraphics();
//1.設置背景色
setBackground(g);
//2.設置邊框
setBorder(g);
//3.畫干擾線
drawRandomLine(g);
//4.寫隨機數
String random = drawRandomNum((Graphics2D)g);
request.getSession().setAttribute("checkcode", random);
//5.圖形寫給瀏覽器
response.setHeader("Content-Type", "image/jpeg");
//發頭控制瀏覽器不要緩存
response.setDateHeader("expries", -1);
response.setHeader("Cache-Control", "no-cache");
response.setHeader("Pragma", "no-cache");
ImageIO.write(image,"jpg",response.getOutputStream());
}
private void setBackground(Graphics g){
g.setColor(Color.WHITE);
g.fillRect(0, 0, WIDTH, HEIGHT);
}
private void setBorder(Graphics g){
g.setColor(Color.BLUE);
g.drawRect(1, 1, WIDTH-2, HEIGHT-2);
}
private void drawRandomLine(Graphics g){
g.setColor(Color.GREEN);
for(int i = 0 ;i < 5; i++){
int x1 = new Random().nextInt(WIDTH);
int y1 = new Random().nextInt(HEIGHT);
int x2 = new Random().nextInt(WIDTH);
int y2 = new Random().nextInt(HEIGHT);
g.drawLine(x1, y1, x2, y2);
}
}
private String drawRandomNum(Graphics2D g){
g.setColor(Color.RED);
g.setFont(new Font("宋體",Font.BOLD,20));
StringBuffer sb = new StringBuffer();
//[\u4e00-\u9fa5] 表示：所有的漢字在unicode編碼4e00~9fa5之間
//常用漢字的unicode編碼
String base = "\u7684\u4e00\u4e86\u662f\u6211\u4e0d\u5728\u4eba\u4eec\u6709\u6765\u4ed6\u8fd9\u4e0a\u7740\u4e2a\u5730\u5230\u5927\u91cc\u8bf4\u5c31\u53bb\u5b50\u5f97\u4e5f\u548c\u90a3\u8981\u4e0b\u770b\u5929\u65f6\u8fc7\u51fa\u5c0f\u4e48\u8d77\u4f60\u90fd\u628a\u597d\u8fd8\u591a\u6ca1\u4e3a\u53c8\u53ef\u5bb6\u5b66\u53ea\u4ee5\u4e3b\u4f1a\u6837\u5e74\u60f3\u751f\u540c\u8001\u4e2d\u5341\u4ece\u81ea\u9762\u524d\u5934\u9053\u5b83\u540e\u7136\u8d70\u5f88\u50cf\u89c1\u4e24\u7528\u5979\u56fd\u52a8\u8fdb\u6210\u56de\u4ec0\u8fb9\u4f5c\u5bf9\u5f00\u800c\u5df1\u4e9b\u73b0\u5c71\u6c11\u5019\u7ecf\u53d1\u5de5\u5411\u4e8b\u547d\u7ed9\u957f\u6c34\u51e0\u4e49\u4e09\u58f0\u4e8e\u9ad8\u624b\u77e5\u7406\u773c\u5fd7\u70b9\u5fc3\u6218\u4e8c\u95ee\u4f46\u8eab\u65b9\u5b9e\u5403\u505a\u53eb\u5f53\u4f4f\u542c\u9769\u6253\u5462\u771f\u5168\u624d\u56db\u5df2\u6240\u654c\u4e4b\u6700\u5149\u4ea7\u60c5\u8def\u5206\u603b\u6761\u767d\u8bdd\u4e1c\u5e2d\u6b21\u4eb2\u5982\u88ab\u82b1\u53e3\u653e\u513f\u5e38\u6c14\u4e94\u7b2c\u4f7f\u5199\u519b\u5427\u6587\u8fd0\u518d\u679c\u600e\u5b9a\u8bb8\u5feb\u660e\u884c\u56e0\u522b\u98de\u5916\u6811\u7269\u6d3b\u90e8\u95e8\u65e0\u5f80\u8239\u671b\u65b0\u5e26\u961f\u5148\u529b\u5b8c\u5374\u7ad9\u4ee3\u5458\u673a\u66f4\u4e5d\u60a8\u6bcf\u98ce\u7ea7\u8ddf\u7b11\u554a\u5b69\u4e07\u5c11\u76f4\u610f\u591c\u6bd4\u9636\u8fde\u8f66\u91cd\u4fbf\u6597\u9a6c\u54ea\u5316\u592a\u6307\u53d8\u793e\u4f3c\u58eb\u8005\u5e72\u77f3\u6ee1\u65e5\u51b3\u767e\u539f\u62ff\u7fa4\u7a76\u5404\u516d\u672c\u601d\u89e3\u7acb\u6cb3\u6751\u516b\u96be\u65e9\u8bba\u5417\u6839\u5171\u8ba9\u76f8\u7814\u4eca\u5176\u4e66\u5750\u63a5\u5e94\u5173\u4fe1\u89c9\u6b65\u53cd\u5904\u8bb0\u5c06\u5343\u627e\u4e89\u9886\u6216\u5e08\u7ed3\u5757\u8dd1\u8c01\u8349\u8d8a\u5b57\u52a0\u811a\u7d27\u7231\u7b49\u4e60\u9635\u6015\u6708\u9752\u534a\u706b\u6cd5\u9898\u5efa\u8d76\u4f4d\u5531\u6d77\u4e03\u5973\u4efb\u4ef6\u611f\u51c6\u5f20\u56e2\u5c4b\u79bb\u8272\u8138\u7247\u79d1\u5012\u775b\u5229\u4e16\u521a\u4e14\u7531\u9001\u5207\u661f\u5bfc\u665a\u8868\u591f\u6574\u8ba4\u54cd\u96ea\u6d41\u672a\u573a\u8be5\u5e76\u5e95\u6df1\u523b\u5e73\u4f1f\u5fd9\u63d0\u786e\u8fd1\u4eae\u8f7b\u8bb2\u519c\u53e4\u9ed1\u544a\u754c\u62c9\u540d\u5440\u571f\u6e05\u9633\u7167\u529e\u53f2\u6539\u5386\u8f6c\u753b\u9020\u5634\u6b64\u6cbb\u5317\u5fc5\u670d\u96e8\u7a7f\u5185\u8bc6\u9a8c\u4f20\u4e1a\u83dc\u722c\u7761\u5174\u5f62\u91cf\u54b1\u89c2\u82e6\u4f53\u4f17\u901a\u51b2\u5408\u7834\u53cb\u5ea6\u672f\u996d\u516c\u65c1\u623f\u6781\u5357\u67aa\u8bfb\u6c99\u5c81\u7ebf\u91ce\u575a\u7a7a\u6536\u7b97\u81f3\u653f\u57ce\u52b3\u843d\u94b1\u7279\u56f4\u5f1f\u80dc\u6559\u70ed\u5c55\u5305\u6b4c\u7c7b\u6e10\u5f3a\u6570\u4e61\u547c\u6027\u97f3\u7b54\u54e5\u9645\u65e7\u795e\u5ea7\u7ae0\u5e2e\u5566\u53d7\u7cfb\u4ee4\u8df3\u975e\u4f55\u725b\u53d6\u5165\u5cb8\u6562\u6389\u5ffd\u79cd\u88c5\u9876\u6025\u6797\u505c\u606f\u53e5\u533a\u8863\u822c\u62a5\u53f6\u538b\u6162\u53d4\u80cc\u7ec6";
int x = 5; //第一個字的x座標
for(int i = 0;i<4;i++){
int degree = new Random().nextInt()%30;//-30~30
String ch = base.charAt(new Random().nextInt(base.length()))+"";
sb.append(ch);
g.rotate(degree*Math.PI/180, x, 20);//設置旋轉角度
g.drawString(ch, x, 20);
g.rotate(-degree*Math.PI/180, x, 20);
x = x + 30;
}
return sb.toString();
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request, response);
}
}html代碼：
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>register.html</title>
<meta http-equiv="Content-Type" content="text/html;charset=UTF-8"/>
<script type="text/javascript">
function changeImage(img){
img.src = img.src + "?" + new Date().getTime();
}
</script>
</head>
<body>
<form action="/day07/servlet/RegisterServlet" method="post">
用戶名：<input type="text" name="username"/><br/>
密碼：<input type="password" name="password"/><br/>
認證碼：<input type="text" name="checkcode"/>
<img src="/day07/servlet/ImageServlet" οnclick="changeImage(this)" title="換一張" style="cursor:hand"/><br/>
<input type="submit" value="註冊"/>
</form>
</body>
</html> Servlet代碼：
//處理註冊請求
public class RegisterServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
//認證碼是漢字，所以要設置一下request編碼
request.setCharacterEncoding("UTF-8");
//處理註冊請求之前，檢驗認證碼是否有效
String client_checkcode = request.getParameter("checkcode");
String server_checkcode = (String)request.getSession().getAttribute("checkcode");
if(client_checkcode!=null&&server_checkcode!=null&&client_checkcode.equals(server_checkcode)){
System.out.println("client_checkcode = " + client_checkcode);
System.out.println("server_checkcode = " + server_checkcode);
System.out.println("處理註冊請求!");
}
else{
System.out.println("client_checkcode = " + client_checkcode);
System.out.println("server_checkcode = " + server_checkcode);
System.out.println("認證碼錯誤!");
}
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request, response);
}
}