Filter细节处理web.xml、Filte细节处理执行流程&生命周期

Filter细节处理web.xml

web.xml配置

    <filter>
        <filter-name>FilterDome1</filter-name>
        <filter-class>ssr.web.filter.FilterDome1</filter-class>
    </filter>
    <filter-mapping>
        <filter-name>FilterDome1</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>
</web-app>

Filte细节处理执行流程&生命周期

public class FilterDome1 implements Filter {
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {

    }

    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        System.out.println("被执行了..");
        chain.doFilter(request,response);
        System.out.println("又回来了...");
    }

    @Override
    public void destroy() {

    }
}

<html>
  <head>
    <title>$Title$</title>
  </head>
  <body>
    index.jsp....

  <%
    System.out.println("index.jsp....");
  %>
  </body>
</html>

    <filter>
        <filter-name>FilterDome1</filter-name>
        <filter-class>ssr.web.filter.FilterDome1</filter-class>
    </filter>
    <filter-mapping>
        <filter-name>FilterDome1</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>
</web-app>

我们在来看生命周期

public class FilterDome1 implements Filter {
    @Override
//    服务器启动都，会创建创建调用init
    public void init(FilterConfig filterConfig) throws ServletException {

    }


    @Override
//    服务启动后 会执行
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        System.out.println("被执行了..");
        chain.doFilter(request,response);
        System.out.println("又回来了...");
    }

    @Override
//    正常关闭后执行...
    public void destroy() {

    }
}