import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import java.io.IOException;
//@WebFilter("/hello.jsp")
@WebFilter("/*")
public class FilterDemo2 implements Filter {
@Override
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
//1. 放行前，对 request数据进行处理
System.out.println("2.FilterDemo...");
//放行
chain.doFilter(request,response);
//2. 放行后，对Response 数据进行处理
System.out.println("4.FilterDemo...");
}
@Override
public void init(FilterConfig filterConfig) throws ServletException {
}
@Override
public void destroy() {
}
}