SpringBoot + Vue前后端分离图片上传到本地并前端访问图片

同理应该可用于其他文件

图片上传

application.yml

配置相关常量

prop:
  upload-folder: E:/test/
# 配置SpringMVC文件上传限制，默认1M。注意MB要大写，不然报错。SpringBoot版本不同，配置项不同
spring:
  servlet:
    multipart:
      max-file-size: 50MB
      max-request-size: 50MB

Controller

@Value("${prop.upload-folder}")
private String UPLOAD_FOLDER;

@PostMapping("/upload")
public Result upload(@RequestParam(name = "file", required = false) MultipartFile file, HttpServletRequest request) {
    if (file == null) {
        return ResultUtil.error(0, "请选择要上传的图片");
    }
    if (file.getSize() > 1024 * 1024 * 10) {
        return ResultUtil.error(0, "文件大小不能大于10M");
    }
    //获取文件后缀
    String suffix = file.getOriginalFilename().substring(file.getOriginalFilename().lastIndexOf(".") + 1, file.getOriginalFilename().length());
    if (!"jpg,jpeg,gif,png".toUpperCase().contains(suffix.toUpperCase())) {
        return ResultUtil.error(0, "请选择jpg,jpeg,gif,png格式的图片");
    }
    String savePath = UPLOAD_FOLDER;
    File savePathFile = new File(savePath);
    if (!savePathFile.exists()) {
        //若不存在该目录，则创建目录
        savePathFile.mkdir();
    }
    //通过UUID生成唯一文件名
    String filename = UUID.randomUUID().toString().replaceAll("-","") + "." + suffix;
    try {
        //将文件保存指定目录
        file.transferTo(new File(savePath + filename));
    } catch (Exception e) {
        e.printStackTrace();
        return ResultUtil.error(0, "保存文件异常");
    }
    //返回文件名称
    return ResultUtil.success(ResultEnum.SUCCESS, filename, request);
}

前端访问图片

前端浏览器在http协议下因为安全原因无法直接访问本地文件

后端拦截器中配置对应url访问本地文件，若有相关拦截器则在拦截器中放行

@Configuration
public class MyInterceptorConfig extends WebMvcConfigurationSupport {

    @Value("${prop.upload-folder}")
    private String UPLOAD_FOLDER;

    @Autowired
    private JwtInterceptor jwtInterceptor;

    @Override
    protected void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(jwtInterceptor)
                .addPathPatterns("/**")
                .excludePathPatterns("/login")
                .excludePathPatterns("/img/**");
    }

    @Override
    public void addResourceHandlers(ResourceHandlerRegistry registry) {
        registry.addResourceHandler("/img/**").addResourceLocations("file:" + UPLOAD_FOLDER);
    }
}

前端直接通过/img/图片名称即可拿到