小编Nic*_*lla的帖子

我想帮助理解java Filters的特定行为:我编写了一个简单的Filter来获取所有用户请求,如果未记录的用户需要受限资源,则过滤器会将用户转发到主页.这是我的代码:

public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
    // TODO Auto-generated method stub
    // place your code here

    HttpServletRequest req = (HttpServletRequest) request;
    String uri = req.getRequestURI();

    System.out.println("\n\nFILTERING...\n\n");

    //Se la risorsa appartiene all'area ristretta e l'utente non è
    //loggato lo sbatto fuori
    if(uri.contains("restricted") && (req.getSession(false) == null || req.getSession(false).getAttribute("user") == null)) {

        System.out.println("\n\nCannot access\n\n");
        //((HttpServletResponse) response).sendRedirect("/Hotel/index.jsp");
        req.getRequestDispatcher("/index.jsp").forward(request, response);
    }
    else {
        // pass the request along the filter chain
        System.out.println("\n\nNext step\n\n");
        chain.doFilter(request, response);
    } …