使用@WebFilter注解时 必须有@ServletComponentScan注解将带有@WebFilter的类包含进去。

package com.guoxiaocha;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.web.servlet.ServletComponentScan;

/**
 * 启动类
 *
 * @author guoxiaocha
 * @date 2022/01/26 11:59
 */
@SpringBootApplication
@ServletComponentScan // 必须有一个注解将带有@WebFilter的类包含进去。
public class WebApplication {

    public static void main(String[] args) {
        SpringApplication.run(WebApplication.class, args);
    }
}

package com.guoxiaocha.filters;


import org.springframework.core.annotation.Order;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import java.io.IOException;

/**
 * @author guoxiaocha
 * @date 2022/01/27 8:51
 */
@WebFilter(urlPatterns = "/test/*",filterName = "myFilter")
@Order(1) // filter顺序 越小越在前
public class MyFilter implements Filter {
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {

    }

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest request =  (HttpServletRequest)servletRequest;
        String requestURI = request.getRequestURI();
        String method = request.getMethod();
        System.out.println(requestURI + "---"+ method);
        filterChain.doFilter(servletRequest,servletResponse);
    }

    @Override
    public void destroy() {

    }
}

SpringBootApplication 上使用@ServletComponentScan 注解后
Servlet可以直接通过@WebServlet注解自动注册
Filter可以直接通过@WebFilter注解自动注册
Listener可以直接通过@WebListener 注解自动注册

也可以通过 【@Component+@Order】实现