SpringBoot自定义过滤器

1、启动类加注解：@ServletComponentScan

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2、创建自定义的Filter类，在类上标注要过滤的url，并实现Filter接口，重写doFilter方法；在方法中，查找session有没有对应的用户信息

package com.cxj.filter;

import com.cxj.entity.Admin;
import org.springframework.stereotype.Component;

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

@Component
@WebFilter(urlPatterns = {"/main.html"},filterName = "adminFilter")
public class AdminFilter 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;
        HttpServletResponse response = (HttpServletResponse) servletResponse;
        HttpSession session = request.getSession();
        Admin admim = (Admin) session.getAttribute("admin");
        if (admim == null) {
            response.sendRedirect("login.html");
        } else {
            filterChain.doFilter(servletRequest, servletResponse);
        }
    }

    @Override
    public void destroy() {

    }
}