如何使用過濾器進行登錄驗證

一:實現思路

(1)將request強轉成HttpServletRequest,這樣才有getRequestURI()方法

(2)獲取資源訪問路徑

(3)判斷uri中是否有登錄選項,要注意排除掉css/js/圖片/驗證碼等資源

(4)如果包含登錄選項,直接放行,如果不包含,則需要驗證用戶是否登錄

(5)從session中獲取user,登錄了就放行,沒有登錄就轉發到登錄頁面

二:代碼實現

<code>
@WebFilter("/*")
public class LoginFilter implements Filter {
    public void destroy() {
    }

    public void doFilter(ServletRequest req, ServletResponse resp, FilterChain chain) throws ServletException, IOException {
       //先強轉成HttpServletRequest,這樣才有getRequestURI()方法
        HttpServletRequest request = (HttpServletRequest) req;
        //獲取資源訪問路徑
        String uri = request.getRequestURI();
        System.out.println(uri);
        //判斷uri中是否有登錄選項
        if(uri.contains("login_v2.jsp")||uri.contains("/login")||uri.contains("/css/")|| uri.contains("/js/")|| uri.contains("/fonts/")||uri.contains("/code")){
            //直接放行
            chain.doFilter(req, resp);
        }else {
            //判斷session中是否有user
            //有,直接放行
            Object user = request.getSession().getAttribute("user");
                if(user!=null){
                    chain.doFilter(req, resp);
                }else {
                    //沒有,提醒去登錄,並請求轉發到登錄頁面
                    request.setAttribute("login-msg","您尚未登錄,請登錄");
                    request.getRequestDispatcher("/login_v2.jsp").forward(request,resp);
                }


        }

    }

    public void init(FilterConfig config) throws ServletException {

    }

}

/<code>

關鍵字: HttpServletRequest user 包含