Java实例讲解文件上传与跨域问题

@Controller
@RequestMapping("upload")
public class UploadController {
 
    @Autowired
    private UploadService uploadService;
 
    @PostMapping("image")
    public ResponseEntity<String> uploadImage(@RequestParam("file") MultipartFile file){
       String url= this.uploadService.uploadImage(file);
       if (StringUtils.isBlank(url)){
           return ResponseEntity.badRequest().build();
       }
        return ResponseEntity.status(httpstatus.CREATED).body(url);
    }
}

@Service
public class UploadService {
 
    //用于判断文件的类型，暂时只判断了“image/gif","image/jpeg”
    private static final List<String> CONTENT_TYPES= Arrays.asList("image/gif","image/jpeg");
 
    private static final Logger LOGGER= LoggerFactory.getLogger(UploadService.class);
 
    
    public String uploadImage(MultipartFile file) {
 
        String originalFilename = file.getOriginalFilename();
        //校验文件类型
        //方法一:截取字符串
        String afterLast = StringUtils.substringAfterLast(".", originalFilename);
        //方法二：使用getContentType方法
        String contentType = file.getContentType();
        if (!CONTENT_TYPES.contains(contentType)){
            LOGGER.info("文件类型不合法："+originalFilename);
            return null;
        }
        //校验文件内容
        try {
            //获取文件流
            BufferedImage bufferedImage = ImageIO.read(file.getInputStream());
            if (bufferedImage==null){
                LOGGER.info("文件内容不合法：{}",originalFilename);
                return null;
            }
            //保存到服务器   E:\Leyou\image
            //将接收到的文件传输到给定的目标文件。
            file.transferTo(new File("E:\\Leyou\\Image\\"+originalFilename));
            
            //返回URL，进行回显
            //可以使用Nginx-图片服务器
            return "Http://image.leyou.com/"+originalFilename;
        } catch (Exception e) {
            LOGGER.info("服务器内部错误："+originalFilename);
            e.printStackTrace();
        }
        return null;
    }
}

server {
        listen       80;
        server_name  image.leyou.com;
 
        proxy_set_header X-Forwarded-Host $host;
		proxy_set_header X-Forwarded-Server $host;
		proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
		
		location / {
			root E:\\Leyou\\image;
		}
    }

@Slf4j
public class AuthorizeFilter implements GlobalFilter, Ordered {
 
    //白名单：存放放行的URL
    private List<String> allowPaths;
 
 
    @Override
    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
       
        //获取请求的url路径
        String path = request.getURI().getPath();
        boolean flag=isAllowPath(path);
        if (flag) {
            log.info("请求在白名单中，leyou.filter: {}",path);
            //放行
            return chain.filter(exchange);
        } else {
          //写其他的业务逻辑
            ~~~~
            
        }
    }
 
    private boolean isAllowPath(String path) {
     
          //判断是否允许放行
         if (allowPaths.contains(path)){
             return true;
         }
         return  false;
 
  }

	server {
        listen       80;
        server_name  api.leyou.com;
 
        proxy_set_header X-Forwarded-Host $host;
		proxy_set_header X-Forwarded-Server $host;
		proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
		# 新增加的配置，用于文件上传
		location /api/upload {
			proxy_pass http://127.0.0.1:8082;
			proxy_connect_timeout 600;
			proxy_read_timeout 600;
			
			rewrite "^/api/(.*)$" /$1 break;
		}
		# 网关的配置
		location / {
			proxy_pass http://127.0.0.1:10010;
			proxy_connect_timeout 600;
			proxy_read_timeout 600;
		}
    }

@Configuration
public class LeyouCorsConfiguration {
 
    @Bean
    public CorsFilter corsFilter(){
        //初始化配置对象
        CorsConfiguration configuration = new CorsConfiguration();
        //允许跨域访问的域名
        configuration.addAllowedOrigin("*");
       // configuration.setAllowCredentials(true);  //运行携带cookie
        configuration.addAllowedMethod("*"); //代表所有请求方法
        configuration.addAllowedHeader("*"); //允许携带任何头信息
 
        //初始化cors配置源对象
        UrlBasedCorsConfigurationSource configurationSource=new UrlBasedCorsConfigurationSource();
        configurationSource.reGISterCorsConfiguration("/**",configuration);
 
        //返回CorSfilter实例，参数
        return new CorsFilter(configurationSource);
    }
 
}

client_max_body_size 1024m;