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);

@Override
public void init(FilterConfig config) throws ServletException {
    log.info(">>>>>>>>>过滤器初始化>>>>>>>>>");
}

@Override
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) 

  throws IOException, ServletException { log.info(">>>>>>>>>执行过滤操作>>>>>>>>>"); chain.doFilter(request, response); }

@Override
public 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);

@Override
public void init(FilterConfig config) throws ServletException {
    log.info(">>>>>>>>>过滤器初始化>>>>>>>>>");
}

@Override
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) 

  throws IOException, ServletException { log.info(">>>>>>>>>执行过滤操作>>>>>>>>>"); chain.doFilter(request, response); }

@Override
public 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>>>>>>>>>