package com.zxy.filter;
//urlPatterns配置攔截路徑，這里表示攔截所有
@WebFilter(filterName="loginCheckFilter",urlPatterns = "/*")
@Slf4j
public class LoginCheckFilter implements Filter {
    //路徑匹配器，支持通配符
    public static final AntPathMatcher PATH_MATCHER = new AntPathMatcher();
    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest request = (HttpServletRequest) servletRequest;
        HttpServletResponse response = (HttpServletResponse) servletResponse;
        //1.獲取本次請求的ＵＲＩ
        String requestURI = request.getRequestURI();
        //定義不需要處理的請求路徑，下面的*只是字符串，并不是通配符,后面通過check判斷時*號就視為通配符了
        String[] urls = new String[]{
                "/employee/login",
                "/employee/logout",
                "/backend/**",
                "/front/**"
        };
        //2.判斷本次請求是否需要處理
        boolean check = check(urls,requestURI);
        //3.如果不需要處理，直接放行
        if(check){
            filterChain.doFilter(request,response);
            return;
        }
        //4.如果需要處理，判斷是否登錄
        //登錄狀態(tài)，不需要處理，直接放行
        if(request.getSession().getAttribute("employee")!=null){
            filterChain.doFilter(request,response);
            return;
        }
        //5.如果未登錄則返回未登錄結(jié)果，通過輸出流方式向客戶端頁面響應數(shù)據(jù)，因為我們返回的是void，所以不能return R.error("NOTLOGIN")
        response.getWriter().write(JSON.toJSONString(R.error("NOTLOGIN")));
        return;
    }
    public boolean check(String[] urls,String requestURI){
        for(String url:urls){
            boolean match = PATH_MATCHER.match(url,requestURI);
            if(match){
                return true;
            }
        }
        return false;
    }
}