文件上传（UUID防止重名文件&&阿里云实现云端上传&&MultipartFile接收前端文件）

一、本地存储

MultipartFile 翻译过来就是 "多部分文件对象"。由Spring提供

在 Java 代码中，它是一个接口，代表了客户端上传的一个完整文件。你可以通过它轻松获取文件名、文件大小、文件内容（字节流）等信息，并将其保存到服务器磁盘或云存储中。

java 复制代码

@RestController
@RequestMapping
public class FileUploadController {

    @PostMapping("/upload")
    public Result<String> upload(MultipartFile file) throws IOException {
        //把文件内容存储到本地磁盘
        String originalFilename = file.getOriginalFilename();
        //保证文件的名字是唯一的，从而防止文件覆盖
        originalFilename = UUID.randomUUID().toString()+originalFilename.substring(originalFilename.lastIndexOf("."));
        //本地存储
        file.transferTo(new File("C:\\Users\\c1338\\Desktop\\files\\"+originalFilename));

        return Result.success(url);
    }
}

二、云存储

我们直接参考阿里云官网的api文档制作出相应工具类

java 复制代码

public class AliOssUtil {
    private static final String ENDPOINT = "https://oss-cn-beijing.aliyuncs.com";
    private static final String ACCESS_KEY_ID = "LTAI5tQ8e13igWZUMTjMEEQV";
    private static final String SECRET_ACCESS_KEY = "MffMJoM24sc59SEBEJQDb0cfBVOAC9";
    private static final String BUCKET_NAME = "big-event-gwd";

    //上传文件,返回文件的公网访问地址
    public static String uploadFile(String objectName, InputStream inputStream){
        // 创建OSSClient实例。
        OSS ossClient = new OSSClientBuilder().build(ENDPOINT,ACCESS_KEY_ID,SECRET_ACCESS_KEY);
        //公文访问地址
        String url = "";
        try {
            // 创建存储空间。
            ossClient.createBucket(BUCKET_NAME);
            ossClient.putObject(BUCKET_NAME, objectName, inputStream);
            url = "https://"+BUCKET_NAME+"."+ENDPOINT.substring(ENDPOINT.lastIndexOf("/")+1)+"/"+objectName;
        } catch (OSSException oe) {
            System.out.println("Caught an OSSException, which means your request made it to OSS, "
                    + "but was rejected with an error response for some reason.");
            System.out.println("Error Message:" + oe.getErrorMessage());
            System.out.println("Error Code:" + oe.getErrorCode());
            System.out.println("Request ID:" + oe.getRequestId());
            System.out.println("Host ID:" + oe.getHostId());
        } catch (ClientException ce) {
            System.out.println("Caught an ClientException, which means the client encountered "
                    + "a serious internal problem while trying to communicate with OSS, "
                    + "such as not being able to access the network.");
            System.out.println("Error Message:" + ce.getMessage());
        } finally {
            if (ossClient != null) {
                ossClient.shutdown();
            }
        }
        return url;
    }
}