过滤器Filter

 

 

public class CharacterEncodingFilter  implements Filter {

    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
        System.out.println("过滤器初始化");
    }

    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        request.setCharacterEncoding("utf-8");
        response.setCharacterEncoding("utf-8");
        response.setContentType("text/html;charset =utf-8");
        System.out.println("过滤器执行前");
        chain.doFilter(request,response);
        System.out.println("过滤器执行后");
    }
    @Override
    public void destroy() {
        System.out.println("过滤器销毁");
    }
}