SpringBoot使用Filter

对全部请求进行Filter

Filter：

package com.example.demo.filter;

import org.springframework.core.Ordered;
import org.springframework.core.annotation.Order;
import org.springframework.stereotype.Component;

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

@Component//让容器管理该类
@Order(Ordered.HIGHEST_PRECEDENCE)//设置加载顺序最先
public class FilterTest implements Filter {
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
        System.out.println("Filter初始化");
    }

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        System.out.println("这里开始执行Filter了哈");
        filterChain.doFilter(servletRequest, servletResponse);
    }

    @Override
    public void destroy() {
        System.out.println("结束了哦");
    }
}

controller：

package com.example.demo.controller;

import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class TestController {
    @GetMapping("testFilter")
    public String testFilter() {
        System.out.println("看到哈，Controller开始了哦");
        return "第一次请求执行完成了哈";
    }
}

还有两种方式，可以配置对那些路径进行filter

　　看这里：https://blog.csdn.net/qq_27905183/article/details/79078561