1.
if(p==null){
Chain.doFilter(request,response);
}2.
if(user==null){
request.setAttribute("message","对不起,请先登录!!");
request.getRequestDispatcher("/message.jsp").forward(request, response);
return;
}不带参数的return;是什么意思?
1处为什么不用return,而2处用return呢?有什么区别呢?returnjava