JSP页面访问用户验证(2)

来源：未知责任编辑：责任编辑发表时间:2014-05-20 18:32　点击:次

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</filter-mapping>
注：目前配置方式仅仅是在用户访问page222.jsp的时候才走过滤器，也可以配置/*, /user/*等目录进行批量网页过滤

然后，在 LoginFilter.java（web.xml配置文件中的com.homer.LoginFilter）文件中，进行过滤验证：
[java
public class LoginFilter implements Filter {
    @Override
    public void init(FilterConfig arg0) throws ServletException {
    }

    @Override
    public void doFilter(ServletRequest arg0, ServletResponse arg1, FilterChain arg2) throws IOException, ServletException {
        HttpServletRequest request = (HttpServletRequest)arg0;
        HttpServletResponse response = (HttpServletResponse)arg1;

        HttpSession session = request.getSession();
        if(session.getAttribute("userinfo") == null) {
            response.setCharacterEncoding("utf-8");
            PrintWriter out = response.getWriter();
            out.print("<script>alert('您还没有登录，请登录...'); window.location='userlogin.html' </script>");
            out.flush();
            out.close();

//          request.setAttribute("loginError", "您还没有登录，请登录...");
//          request.getRequestDispatcher("userlogin.html").forward(request, response);
        } else {
            arg2.doFilter(request, response);
        }
    }

    @Override
    public void destroy() {
    }
}

用户登录验证
用户登录验证，有两种方式：JSP网页前端和Java（Serlvet）后台
1） JSP网页前端验证（login.jsp）
[html]
<%
    String USERNAME = "admin";
    String USERPWD = "123456";

    request.setCharacterEncoding("utf8");

    String userName = request.getParameter("username").trim();