原创：自定义过虑器及配置

package com.test;

import javax.servlet.*;
import java.io.IOException;

public class FilterStudy implements Filter {


    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
        System.out.println("asplover 自定义过虑器初始化");
    }

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        System.out.println("asplover 自定义过滤器要做的事情");
        System.out.println(servletRequest);
    }

    @Override
    public void destroy() {
        System.out.println("asplover 自定义过虑器销毁");
    }
}

<!--  过滤器配置标签有两个filter和filter-mapping-->
<filter>
  <filter-name>filterStudy</filter-name>
  <filter-class>com.test.FilterStudy</filter-class>
  <init-param>
    <param-name>paraName2</param-name>
    <param-value>paraName2变量的值</param-value>
  </init-param>
</filter>
  <filter-mapping>
    <filter-name>filterStudy</filter-name>
    <url-pattern>/*</url-pattern>
  </filter-mapping>