本文實例為大家分享了java實現自動登錄的具體代碼，供大家參考，具體內容如下
- 當你勾選（記住登錄狀態），用cookie保存用戶名和密碼。不勾選，cookie失效。
- 所有的頁面都要經過autoLoginFilter.java 的過濾器，在這類中，必須要判斷cookies不為null，獲得所有的cookie，得到name為user的cookie，進行用戶名和密碼的驗證，如果不為null，則將user存入session。
- 在LoginServlet.java中，獲得username和password參數，進行dao驗證，如果不為空，放入seesion中，進行頁面跳轉。
- 創建cookie對象。setpath("/"),表示本應用下的所有路徑都能訪問此cookie。
- 對于已經正確登錄的用戶，再次訪問其他頁面必定會再次經過autoLoginFilter，這時，判斷當前session中的user是否為null，不為null，直接通過。
- 對于**login.jsp的有關頁面，不需要經過autoLoginFilter。
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package com.learning.web.servlet;import java.io.IOException;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;import com.learning.domain.User;import com.learning.service.UserService;@WebServlet("/servlet/loginServlet")public class LoginServlet extends HttpServlet { private static final long serialVersionUID = 1L; protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { String username = request.getParameter("username"); String password = request.getParameter("password"); String autologin = request.getParameter("autologin"); UserService userService=new UserService(); User user = userService.findUser(username, password); //user不為null，則登錄成功 if (user!=null) { //創建cookie來保存用戶信息 Cookie cookie=new Cookie("user", user.getUsername()+"&"+user.getPassword()); cookie.setPath("/"); //autologin不為null，則記住了登錄狀態 if (autologin!=null) { cookie.setMaxAge(1*60*60*24);//一天的有效時間 } else { cookie.setMaxAge(0); } response.addCookie(cookie); request.getSession().setAttribute("user", user); request.getRequestDispatcher("/home.jsp").forward(request, response); }else { response.sendRedirect(request.getContextPath()+"/homeLogin.jsp"); } } protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doGet(request, response); }} |
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package com.learning.web.filter;import java.io.IOException;import javax.servlet.Filter;import javax.servlet.FilterChain;import javax.servlet.FilterConfig;import javax.servlet.ServletException;import javax.servlet.ServletRequest;import javax.servlet.ServletResponse;import javax.servlet.annotation.WebFilter;import javax.servlet.annotation.WebInitParam;import javax.servlet.http.Cookie;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import javax.servlet.http.HttpSession;import javax.servlet.jsp.jstl.core.Config;import com.learning.domain.User;import com.learning.service.UserService;@WebFilter(urlPatterns="/*",initParams={@WebInitParam(name="autologin",value="login"),@WebInitParam(name="",value="")})public class AutoFilter implements Filter{ private FilterConfig filterConfig; @Override public void destroy() { } @Override public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException { // 轉換對象 HttpServletRequest httpServletRequest = (HttpServletRequest) request; HttpServletResponse httpServletResponse = (HttpServletResponse) response; // 獲得訪問的路徑 String uri = httpServletRequest.getRequestURI(); String contextPath = httpServletRequest.getContextPath(); uri = uri.substring(contextPath.length() + 1); // 獲得初始化參數 String login = filterConfig.getInitParameter("autologin"); System.out.println("直接通行的路徑："+login); // 不包含"login"的路徑就要進行過濾 （xxxlogin.jsp 不需要自動登錄） if (!uri.contains(login)) { HttpSession session = httpServletRequest.getSession(); User u = (User) session.getAttribute("user"); if (u != null) { System.out.println("session不為null"); chain.doFilter(request, response); } else { // 處理業務邏輯 // 1.獲得cookie 得到User的信息 String username = ""; String password = ""; UserService userService = new UserService(); Cookie[] cookies = httpServletRequest.getCookies(); for (int i = 0;cookies!=null&& i < cookies.length; i++) { if ("user".equals(cookies[i].getName())) { String string = cookies[i].getValue(); String[] values = string.split("&"); username = values[0]; password = values[1]; User user = userService.findUser(username, password); // 不為空則放入session if (user != null) { System.out.println("自動登錄了"); httpServletRequest.getSession().setAttribute("user", user); } } } } } // 2.放行 chain.doFilter(request, response); } @Override public void init(FilterConfig filterConfig) throws ServletException { this.filterConfig=filterConfig; }} |
以上就是本文的全部內容，希望對大家的學習有所幫助，也希望大家多多支持服務器之家。
