我們?cè)谝粋€(gè)網(wǎng)站注冊(cè)賬號(hào)以后會(huì)有提示下次是否自動(dòng)登錄，如果我們選擇下次自動(dòng)登錄，那么服務(wù)器端就會(huì)把你的賬號(hào)和密碼保存在Cookie中，并返回給客戶端。下次在登錄的時(shí)候Http協(xié)議會(huì)帶上你的Cookie中的內(nèi)容去驗(yàn)證信息，因?yàn)榉?wù)器中已經(jīng)存儲(chǔ)你的信息，下次登錄就會(huì)通過(guò)驗(yàn)證，并直接進(jìn)入你的主頁(yè)。
下面是登錄的代碼：
public class LoginServlet extends HttpServlet 
{
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
this.doPost(request, response);
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
String username=request.getParameter("username");
String password=request.getParameter("password");
String savetime=request.getParameter("saveTime");
if(CheckLogin.login(username, password)){
if(null!=savetime){
int saveTime=Integer.parseInt(savetime);//這里接受的表單值為天來(lái)計(jì)算的
int seconds=saveTime*24*60*60;
Cookie cookie = new Cookie("user", username+"=="+password);
cookie.setMaxAge(seconds);
response.addCookie(cookie);
}
request.setAttribute("username",username);
request.getRequestDispatcher("/main126.jsp").forward(request,response);
}
else{
request.getRequestDispatcher("/failure.jsp").forward(request,response);
}
}
}
驗(yàn)證代碼：
public class IndexFilter implements Filter {
public void destroy() {
}
public void doFilter(ServletRequest arg0, ServletResponse arg1,
FilterChain arg2) throws IOException, ServletException {
System.out.println("every request pass here haha");
HttpServletRequest request = (HttpServletRequest) arg0;
HttpServletResponse response = (HttpServletResponse) arg1;
Cookie[] cookies = request.getCookies();
String[] cooks = null;
String username = null;
String password = null;
if (cookies != null) {
for (Cookie coo : cookies) {
String aa = coo.getValue();
cooks = aa.split("==");
if (cooks.length == 2){
username = cooks[0];
password = cooks[1];
}
}
}
System.out.println("cookie username | " + username);
System.out.println("cookie password | " + password);
if (CheckLogin.login(username, password)){
System.err.println("check successfully cookie data ");
request.getSession().setAttribute("username",username);
request.getRequestDispatcher("/main126.jsp").forward(request, response);
}
else{
arg2.doFilter(request,response );
}
}
public void init(FilterConfig arg0) throws ServletException {
// TODO Auto-generated method stub
}
}
public class CheckLogin {
public static boolean login(String username, String password){
if ("admin".equals(username) && "123456".equals(password)) {
return true;
}
else{
return false;
}
}
}
我們看看沒有登錄的結(jié)果：
我們?cè)倏纯匆呀?jīng)登錄的結(jié)果：
