spring boot 配置Filter过滤器的两种方式

springboot 配置 自定的 过滤器需要将自定义的过滤配实现 javax.servlet.Filter接口

 demo1：在自定义过滤器上添加组件注解

package com.dayu.filter;

import org.springframework.context.annotation.ComponentScan;
import org.springframework.stereotype.Component;

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

/**
 * @author 大宇
 * Description 过滤器处理所有请求
 * 这里写两种配置方式：一种在myFilter类上加上@Component注解，
 * 另一种不添加这个注解，在config包下创建一个配置类config.WebConfig，通过配置Bean
 */
@Component
public class MyFilter implements Filter {
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
        System.out.println("MyFilter.init");
    }

    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain filterChain) throws IOException, ServletException {
        System.out.println("time filter start");
        long start = new Date().getTime();
        filterChain.doFilter(request,response);
        System.out.println(new Date().getTime()-start);
        System.out.println("time filter end");
    }

    @Override
    public void destroy() {
        System.out.println("MyFilter.destroy");
    }
}

第二种就是讲上面的注解去掉，在自定义config中用配置Bean的方式装配

package com.dayu.config;

import com.dayu.filter.MyFilter;
import org.springframework.boot.web.servlet.FilterRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import java.util.ArrayList;

/**
 * @author 大宇
　Configuration注解配置很重要
 */
@Configuration
public class WebConfig  {
    @Bean
    public FilterRegistrationBean timeFilter() {
        FilterRegistrationBean registrationBean = new FilterRegistrationBean();
        MyFilter myFilter = new MyFilter();
        registrationBean.setFilter(myFilter);
        ArrayList<String> urls = new ArrayList<>();
        urls.add("/*");//配置过滤规则
        registrationBean.setUrlPatterns(urls);
        return registrationBean;
    }
}