1
package lesson3_2.cookie;
2
/**
3
* 使用Cookie技术实现淘宝网效果，
4 * 用户第一访问显示显示用户登录（输入姓名）界面
5 * 当用户登陆一次，以后不需要在登陆并在页面显示“XXX，欢迎您“
6 *
7
*/
8import javax.servlet.*;
9import javax.servlet.http.*;
10import java.io.*;
11import java.util.*;
12
13public class CookieLoginServlet extends HttpServlet {
14 private static final String CONTENT_TYPE = "text/html; charset=GBK";
15
16 //Initialize global variables
17
public void init() throws ServletException {
18
}
19
20 //Process the HTTP Get request
21 public void doGet(HttpServletRequest request, HttpServletResponse response) throws
22 ServletException, IOException {
23
24 request.setCharacterEncoding("gbk");
25 response.setContentType(CONTENT_TYPE);
26
27 PrintWriter out = response.getWriter();
28// 获得输入的用户名
29 String userName =request.getParameter("userName");
30// 从客户端读取Cookie
31 Cookie cookie[] = request.getCookies();
32
33// 声明一个引用来存放找到的Cookie
34 Cookie myCookie = null;
35
36// 如果客户端有Cookie,则查找有没有与userName值相同的Cookie
37 if (cookie != null) {
38 for (int i = 0; i < cookie.length; i++) {
39 if (cookie[i].getName().equals("userName")) {
40 myCookie = cookie[i];
41 break;
42 }
43 }
44 }
45// 没有找到与当前输入的名称相同的Cookie时,则把当前的用户写到Cookie
46 if(userName!=null&&!userName.equals(""))
47 {
48 Cookie newCookie = new Cookie("userName",userName);
49 newCookie.setMaxAge(60*60*24);
50 response.addCookie(newCookie);
51 myCookie=newCookie;
52 }
53
54// 客户端有Cookie时,则读取Cookie,并显示欢迎,否则显示登录页面
55 if (myCookie!=null) {
56 out.println(myCookie.getValue() + ":欢迎您登录");
57 } else {
58
59 out.println("<html>");
60 out.println("<head><title>SendServlet</title></head>");
61 out.println("<body bgcolor=\"#ffffff\">");
62 out.println(
63 "<form action = '/WebModule/cookieloginservlet' method = 'post'>");
64 out.println("<input type='text' name='userName'/>");
65 out.println("<input type = 'submit' value = '登录'/>");
66 out.print("</form>");
67 out.println("</body>");
68 out.println("</html>");
69 }
70 }
71
72 //Process the HTTP Post request
73 public void doPost(HttpServletRequest request, HttpServletResponse response) throws
74 ServletException, IOException {
75 doGet(request, response);
76 }
77
78 //Clean up resources
79 public void destroy() {
80 }
81}
82
83
package lesson3_2.cookie;2
/**
3
* 使用Cookie技术实现淘宝网效果，4
* 用户第一访问显示显示用户登录（输入姓名）界面5
* 当用户登陆一次，以后不需要在登陆并在页面显示“XXX，欢迎您“6
* 7
*/8
import javax.servlet.*;9
import javax.servlet.http.*;10
import java.io.*;11
import java.util.*;12
13
public class CookieLoginServlet extends HttpServlet {
14
private static final String CONTENT_TYPE = "text/html; charset=GBK";15
16
//Initialize global variables17
public void init() throws ServletException {
18
}19
20
//Process the HTTP Get request21
public void doGet(HttpServletRequest request, HttpServletResponse response) throws22
ServletException, IOException {23
24
request.setCharacterEncoding("gbk");25
response.setContentType(CONTENT_TYPE);26
27
PrintWriter out = response.getWriter();28
// 获得输入的用户名29
String userName =request.getParameter("userName");30
// 从客户端读取Cookie31
Cookie cookie[] = request.getCookies();32
33
// 声明一个引用来存放找到的Cookie34
Cookie myCookie = null;35
36
// 如果客户端有Cookie,则查找有没有与userName值相同的Cookie37
if (cookie != null) {38
for (int i = 0; i < cookie.length; i++) {39
if (cookie[i].getName().equals("userName")) {40
myCookie = cookie[i];41
break;42
}43
}44
}45
// 没有找到与当前输入的名称相同的Cookie时,则把当前的用户写到Cookie46
if(userName!=null&&!userName.equals(""))47
{48
Cookie newCookie = new Cookie("userName",userName);49
newCookie.setMaxAge(60*60*24);50
response.addCookie(newCookie);51
myCookie=newCookie;52
}53
54
// 客户端有Cookie时,则读取Cookie,并显示欢迎,否则显示登录页面55
if (myCookie!=null) {56
out.println(myCookie.getValue() + ":欢迎您登录");57
} else {58
59
out.println("<html>");60
out.println("<head><title>SendServlet</title></head>");61
out.println("<body bgcolor=\"#ffffff\">");62
out.println(63
"<form action = '/WebModule/cookieloginservlet' method = 'post'>");64
out.println("<input type='text' name='userName'/>");65
out.println("<input type = 'submit' value = '登录'/>");66
out.print("</form>");67
out.println("</body>");68
out.println("</html>");69
}70
}71
72
//Process the HTTP Post request73
public void doPost(HttpServletRequest request, HttpServletResponse response) throws74
ServletException, IOException {75
doGet(request, response);76
}77
78
//Clean up resources79
public void destroy() {80
}81
}82
83
