1.字符集
@WebFilter(filterName="EcodingFilter",urlPatterns="/*") public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException { // TODO Auto-generated method stub request.setCharacterEncoding("utf-8"); response.setCharacterEncoding("utf-8"); chain.doFilter(request,response); }
2.限制没有登录的用户
设置一个path文件夹，里面的页面只要登录之后才可以查看
建立一个LoginFilter用来查看session中有没有用户登录的信息，如果没有就拦截，如果有就允许登录
@WebFilter(filterName="LoginFilter",urlPatterns="/path/*")
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException { // TODO Auto-generated method stub HttpServletRequest r = (HttpServletRequest)request; HttpServletResponse res = (HttpServletResponse)response; HttpSession session = r.getSession(); String user = (String)session.getAttribute("username"); if(user != null){ chain.doFilter(request, response); }else { String msg = "没有登录"; r.setAttribute("error", msg); r.getRequestDispatcher("/PleaseLogin.jsp").forward(r, res); } }
PleaseLogin.jsp
用来显示错误的error
<body>
${error }
</body>