写了个过滤器,用来判断用户是否登录,没提示错误但就是没编译,什么问题啊?
import java.io.IOException;import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;public class LoginCheckFilter  implements Filter{
protected FilterConfig filterConfig;public void doFilter(ServletRequest request, ServletResponse response, FilterChain filterChain) throws IOException, ServletException {
HttpServletRequest httpRequest = (HttpServletRequest)request;
HttpServletResponse httpResponse = (HttpServletResponse)response;
boolean isValid = true;
String uriStr = httpRequest.getRequestURI().toUpperCase();
if(uriStr.indexOf("LOGIN.JSP") == -1 && httpRequest.getSession().getAttribute("userBean") == null)
isValid = false;
if(isValid){
filterChain.doFilter(request, response);
}
else{
httpResponse.sendRedirect("login.jsp");
}
}public void init(FilterConfig filterconfig) throws ServletException {
 filterConfig = filterconfig;
}public void destroy() {
 filterConfig = null;

}
}