切面编程(3)

public class WebFiler implements Filter{
    //在bean销毁的时候执行
	@Override
	public void destroy() {
		System.out.println("destroy");
		
	}

	@Override
	public void doFilter(ServletRequest request, ServletResponse response,
			FilterChain filter) throws IOException, ServletException {
		System.out.println("前");//拦截处理逻辑
		filter.doFilter(request, response);//正常执行
		System.out.println("后");//返回拦截
	}
    //在bean初始化时候执行
	@Override
	public void init(FilterConfig arg0) throws ServletException {
		arg0.getServletContext();
		System.out.println("init");
	}
}

	<filter>
		<filter-name>WebFilter</filter-name>
		<!-- 配置过滤器的路径,切记类必须实现Filter接口 -->
		<filter-class>com.cn.cis.interceptor.WebFiler</filter-class>
	</filter>
	
	<filter-mapping>
		<filter-name>WebFilter</filter-name>
		<!-- 配置过滤器的路径,配置需要被过滤器拦截的 -->
		<url-pattern>/*</url-pattern>
	</filter-mapping>