过滤器filter的配置（登陆）

public class adminFilter implements Filter {
    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest request= (HttpServletRequest) servletRequest;
        HttpServletResponse response= (HttpServletResponse) servletResponse;
        String uri=request.getRequestURI();//获取相对路径
        User user= (User) request.getSession().getAttribute("user");
        if(uri.endsWith("/login.jsp")||uri.endsWith("/login.do")){
            filterChain.doFilter(request,response);
            return;
        }
        if(user!=null){

            filterChain.doFilter(request,response);
        }else{

            response.sendRedirect("/admin/error/privilege.jsp");
        }
    }
}

adminFilter，web.xml中的配置

<filter>
        <filter-name>adminFilter</filter-name>
        <filter-class>com.bookstore.utils.adminFilter</filter-class>
    </filter>
    <filter-mapping>
        <filter-name>adminFilter</filter-name>
        <url-pattern>/admin/login/*</url-pattern>
        <url-pattern>/admin/notices/*</url-pattern>
        <url-pattern>/admin/orders/*</url-pattern>
        <url-pattern>/admin/products/*</url-pattern>


    </filter-mapping>