1、resource static下有个图片，希望浏览器可以查看这个图片

访问：

若yml设置路径，则可以定义在static下才可以访问

classpath代表类路径，都在target下

也就是项目在运行后的resource下的文件都会到classes下去

无需在target下创建文件夹。在resource下创建文件夹即可

spring.mvc.static-path-pattern=/static/**

spring.mvc.static-path-pattern=/static/**
spring.web.resources.static-locations=classpath:/css

2、文件上传13：00

package com.example.helloworld.controller;

import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;


import javax.servlet.http.HttpServletRequest;
import java.io.File;
import java.io.IOException;

/**
 * @Author Fxdll
 * @Date 2024/4/30 23:05
 * @PackageName:com.example.helloworld.controller
 * @ClassName: FileController
 * @Description: TODO
 * @Version 1.0
 */
@RestController
public class FileUploadController {
    @PostMapping("/upload")
    //等价于@RmoteMapping(value="/uplaod",method=RequestMethod.POST)
    public String up(String nickname, MultipartFile photo, HttpServletRequest request) throws IOException {
        //获取前端传来的昵称
        System.out.println(nickname);
    //获取上传文件的路径
        System.out.println( "文件名"+ photo.getOriginalFilename());
    //获取上传文件的类型
        System.out.println(photo.getContentType());
    //        System.out.println(System.getProperty("user.dir"));
        //获取项目的路径
     String path = request.getServletContext().getRealPath("/upload/");
        //获取上传文件的真实路径
        System.out.println(path);
        //保存文件
        saveFile(photo,path);
        // TODO: 返回上传成功消息
        return "文件上传成功";
    }

    private void saveFile(MultipartFile photo,String path)throws IOException {
//判断路径是否存在，不存在则创建
        File Dir = new File(path);
        if (!Dir.exists()) {

            //创建目录
            Dir.mkdirs();
        }
        File file = new File(path + photo.getOriginalFilename());
        photo.transferTo(file);
    }
}

3、如何让上传的图片也可以访问？

配置静态路径即可

第一个是设置单词上传大小上线

第二个是访问图片静态路径设置

spring.servlet.multipart.max-file-size=10MB
spring.web.resources.static-locations=class:/upload/

4、拦截器

5、拦截器定义

package com.example.helloworld.config;

import com.example.helloworld.interceptor.LoginInterceptor;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;

/**
 * @Author Fxdll
 * @Date 2024/5/3 21:33
 * @PackageName:com.example.helloworld.config
 * @ClassName: Webconfig
 * @Description: TODO
 * @Version 1.0
 */
@Configuration
public class Webconfig implements WebMvcConfigurer {
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(new LoginInterceptor()).addPathPatterns("/user/**");
    }
}

package com.example.helloworld.interceptor;

import org.springframework.web.servlet.HandlerInterceptor;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * @Author Fxdll
 * @Date 2024/4/30 22:31
 * @PackageName:com.example.helloworld.interceptor
 * @ClassName: LoginInterceptor
 * @Description: TODO 拦截器
 * @Version 1.0
 */

/**
 * request:
 * 1.获取请求信息(客户端传来的cooke,url参数,请求体)
 * response:
 * 1.设置响应信息
 */
public class LoginInterceptor  implements HandlerInterceptor {
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        System.out.println("LoginInterceptor");
        return true;
    }
}