上篇文章中说了SpringBoot中是如何使用servlet的，本文将讲解在SpringBoot中对过滤器Filter的实现

一.编写MyFilter实现Filter接口

package com.maxbill.core.webbox.filter;import org.apache.log4j.Logger;import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import java.io.IOException;/*** @功能 自定义过滤器* @作者 zuoshuai(MaxBill)* @日期 2017/7/6* @时间 15:18* @备注 MyFilter*/
public class MyFilter implements Filter {Logger log = Logger.getLogger(MyFilter.class);@Overridepublic void init(FilterConfig config) throws ServletException {log.info(">>>>>>>>>过滤器初始化>>>>>>>>>");}@Overridepublic void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {log.info(">>>>>>>>>执行过滤操作>>>>>>>>>");chain.doFilter(request, response);}@Overridepublic void destroy() {log.info(">>>>>>>>>过滤器销毁>>>>>>>>>");}}

二.增加注解

1.过滤器增加@WebFilter注解，使能够被扫描到

@WebFilter(filterName = "myFilter", urlPatterns = "/*")
public class MyFilter implements Filter {Logger log = Logger.getLogger(MyFilter.class);@Overridepublic void init(FilterConfig config) throws ServletException {log.info(">>>>>>>>>过滤器初始化>>>>>>>>>");}@Overridepublic void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {log.info(">>>>>>>>>执行过滤操作>>>>>>>>>");chain.doFilter(request, response);}@Overridepublic void destroy() {log.info(">>>>>>>>>过滤器销毁>>>>>>>>>");}}

2.启动类增加@ServletComponentScan注解，扫描项目中的filter

package com.maxbill;import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.web.servlet.ServletComponentScan;@ServletComponentScan
@SpringBootApplication
public class MaxbillApplication {public static void main(String[] args) {SpringApplication.run(MaxbillApplication.class, args);}}

启动项目测试：

INFO com.maxbill.core.webbox.filter.MyFilter:23 - >>>>>>>>>过滤器初始化>>>>>>>>>

INFO com.maxbill.core.webbox.filter.MyFilter:29 - >>>>>>>>>执行过滤操作>>>>>>>>>