JavaWeb 利用cookie及过滤器实现30天内自动登录简单步骤

来源：互联网发布：java微信接口开发实例编辑：程序博客网时间：2024/05/29 03:24

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第一步：准备页面

<body>
<h1>用户登录</h1><hr>
<form action="${pageContext.request.contextPath }/servlet/LoginServlet" method="POST">
用户名<input type="text" name="name" />
密码<input type="password" name="password" />
<input type="checkbox" name="autologin" value="true"/>30天内自动登陆
<input type="submit" value="登录"/>
</form>
</body>

第二步：创建自己的MyServlet 来处理自动登录 spring controller同理

public class MyServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
//1，登录校验
//2，如果用户勾选过30天内自动登陆,发送自动登陆cookie
if("true".equals(request.getParameter("autologin"))){
Cookie autologinC = new Cookie("autologin",user.getName()+":"+user.getPassword());
autologinC.setPath(request.getContextPath());
autologinC.setMaxAge(3600*24*30);
response.addCookie(autologinC);
}
//4.重定向到主页
response.sendRedirect(request.getContextPath()+"/index.jsp");
}
}
}

第三步：创建自己的AutoLoginFilter过滤器

@Component()public class AutologinFilter implements Filter {private UserController userController;@Overridepublic void destroy() {// TODO Auto-generated method stub}@Overridepublic void doFilter(ServletRequest request, ServletResponse response,FilterChain chain) throws IOException, ServletException {try {ApplicationContext ctx = new FileSystemXmlApplicationContext("classpath:spring-mvc.xml");this.userController = ctx.getBean(UserController.class);} catch (BeansException e) {e.printStackTrace();}HttpServletRequest req = (HttpServletRequest) request;          HttpServletResponse resp = (HttpServletResponse) response;          //1.只有未登录的用户才能自动登陆          if(req.getSession(false)==null || req.getSession().getAttribute("user")==null){                            //2.只有带了自动登陆cookie的用户才能自动登陆              Cookie [] cs = req.getCookies();              Cookie findC = null;              if(cs!=null){                  for(Cookie c : cs){                      if("autologin".equals(c.getName())){                          findC = c;                          break;                      }                  }              }                            if(findC!=null){                  //3.自动登录Cookie中保存的用户名密码都需要是正确的才能自动登陆                  String loginname = findC.getValue().split(":")[0];                  String password= findC.getValue().split(":")[1];      ModelMap model = new ModelMap();    SerializeObject serializeObject = userController.getLoginBeanInfoByParams(req, resp, model, loginname, password);    if(serializeObject != null){//如果登录成功，则返回主页面    if(ResultType.NORMAL == serializeObject.getStatus()){    request.getRequestDispatcher("user/login?loginname="+loginname+"&password="+password).forward(request, response);    }else{    request.getRequestDispatcher("/login.jsp").forward(request, response);    }    }            }              //无论是否自动登陆,都放行资源              chain.doFilter(request, response);  }        request.getRequestDispatcher("/login.jsp").forward(request, response);}@Overridepublic void init(FilterConfig arg0) throws ServletException {// TODO Auto-generated method stub}}

第三步：注册过滤器

<filter>
<description>自动登陆过滤器</description>
<filter-name>AutologinFilter</filter-name>
<filter-class>com.itheima.filter.AutologinFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>AutologinFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>

扩展：注销功能

public class LogoutServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
if(request.getSession(false)!=null){
request.getSession().invalidate();
//删除自动登录 cookie
Cookie autologinC = new Cookie("autologin", "");
autologinC.setPath(request.getContextPath());
autologinC.setMaxAge(0);
response.addCookie(autologinC);
}
response.sendRedirect(request.getContextPath()+"/index.jsp");
}
}

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JavaWeb 利用cookie及过滤器实现30天内自动登录 简单步骤

JavaWeb 利用cookie及过滤器实现30天内自动登录简单步骤