springboot完成一个线上图片存放地址+实现前后端上传图片+回显

1.路径

注意路径

2.代码：（那个imagePath没什么用，懒的删了），注意你的本地文件夹要有图片，才可以在线上地址中打开查看

package com.xxx.common.config;

import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;

@Configuration
public class ResourceConfigurerAdapter implements WebMvcConfigurer {
    @Value("${image.path}")
    private String imagePath;

    /**
     * 配置资源访问
     * @param registry
     */
    @Override
    public void addResourceHandlers(ResourceHandlerRegistry registry) {
        registry.addResourceHandler("/img/**")
                .addResourceLocations("file:D:/code/img/");  //表示线上的存放的图片的来源：是D盘code下的img（所以你要做的就是将图片上传到这个本地文件夹）
    }

}

3.然后访问就是：localhost:端口号/img/图片名称.图片后缀

4.后端上传图片到特定文件夹：

package com.xxx.common.controller;

import com.xxx.common.service.UserService;
import com.xxx.common.utils.Result;
import org.apache.commons.io.FilenameUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.multipart.MultipartFile;

import java.io.File;
import java.io.IOException;
import java.nio.file.Paths;
import java.util.Map;
import java.util.Random;
import java.util.UUID;

@RestController
@RequestMapping("/api")
@CrossOrigin(origins = "http://localhost:8888") // 允许来自前端服务器的跨域请求
public class FileUploadController {

    @Autowired
    private UserService userService;

    //图片上传的地址
    private static final String UPLOAD_DIR = "D:\\code\\img";

    @PostMapping("/upload")
    public ResponseEntity<?> handleFileUpload(@RequestParam("file") MultipartFile file) {
        if (file.isEmpty()) {
            return ResponseEntity.badRequest().body("文件不能为空");
        }

        try {
            String originalFilename = file.getOriginalFilename();
            // 可以添加更多的文件名检查和清理逻辑
            // 注意：直接使用用户提供的文件名存在安全风险，应该添加必要的校验和清理
            String randomString = generateRandomString(8);
            System.out.println("Random String: " + randomString);

            File destinationFile = new File(UPLOAD_DIR, "TX_"+randomString+originalFilename);
            file.transferTo(destinationFile);

            // 返回文件名作为响应
            return ResponseEntity.ok().body(destinationFile.getName());
        } catch (IOException e) {
            return new ResponseEntity<>("无法保存文件", HttpStatus.INTERNAL_SERVER_ERROR);
        }
    }


    @PostMapping("/updateAvatar")
    public ResponseEntity<?> updateAvatar(@RequestBody Map<String, Object> payload) {

        //拿到现在的avtar的值，使用userMapper去数据表查找是否有该值，有的话就覆盖，然后提示图片已存在图片更新成功，已覆盖之前文件；如果查找不到的话就提示“第一次存入该图片”

        Integer userId = (Integer) payload.get("userId");
        String avatarName = (String) payload.get("avatar");
        userService.updateAvatar(userId, avatarName);
        return ResponseEntity.ok().body("头像更新成功");
    }

    public static String generateRandomString(int length) {
        String uuid = UUID.randomUUID().toString().replaceAll("-", "");
        Random random = new Random();
        StringBuilder result = new StringBuilder(length);

        for (int i = 0; i < length; i++) {
            result.append(uuid.charAt(random.nextInt(uuid.length())));
        }

        return result.toString().toUpperCase();
    }


}

5.前端上传图片调用上面的后端的接口