1      背景介绍 & 效果展示

通过OBS JAVA SDK可以实现批量下载文件，如下载文件夹，效果如下。

注：有关标准存储、低频访问、归档存储三种存储类型的更多信息，参考链接：https://support.huaweicloud.com/usermanual-obs/zh-cn_topic_0050321036.html

图1 桶下面有“FunctionGraphDemo-VideoConvert/”为前缀的文件夹

图2 把上图中的文件夹下载到本地"C:/software/"目录下

2      java代码参考

前提：

需要先下载OBS最新的JAVA SDK，参考官网链接：https://developer.huaweicloud.com/sdk?OBS，并在自己的项目中导入SDK中的JAR包。

       public static void main(String[] args) throws IOException {

                   // 需要将endPoint/ak/sk更新为实际信息

                   String endPoint = "https://your-endpoint";

                   String ak = "*** Provide your Access Key ***";

                   String sk = "*** Provide your Secret Key ***";

                   // 创建ObsClient实例

                   ObsClient obsClient = new ObsClient(ak, sk, endPoint);

                   try

                  {

                                      String bucketName = "bucketXXX";                // 需要将bucketName更新为实际信息

String fileLocatePrefix = "C:/software/";    // 需要下载到本地哪个目录，这里面举例"C:/software/"

                                       ListObjectsRequest request = new ListObjectsRequest(bucketName);

                                       // 指定下载"FunctionGraphDemo-VideoConvert/"文件夹

                                       request.setPrefix("FunctionGraphDemo-VideoConvert/");

                                       request.setMaxKeys(500);

                                       ObjectListing result;

System.out.println("Objects:");

                                       do{

                                                  result = obsClient.listObjects(request);

                                                 for (ObsObject obsObject : result.getObjects())

                                                  {

                                                 System.out.println("\t" + obsObject.getObjectKey());

                                                 DownloadFileRequest requestDownload = new DownloadFileRequest(bucketName, obsObject.getObjectKey());

                                                 requestDownload.setDownloadFile(fileLocatePrefix+obsObject.getObjectKey());

                                                 // 设置分段下载时的最大并发数

                                                 requestDownload.setTaskNum(5);

                                                 // 设置分段大小为10MB

                                                 requestDownload.setPartSize(10 * 1024 * 1024);

                                                 // 开启断点续传模式

                                                 requestDownload.setEnableCheckpoint(true);

                                                  try{

                                                           // 进行断点续传下载

                                                           DownloadFileResult resultDownload = obsClient.downloadFile(requestDownload);

                                                  }catch (ObsException e) {

System.out.println("Response Code: " + e.getResponseCode());

                                                           System.out.println("Error Message: " + e.getErrorMessage());

                                                           System.out.println("Error Code:       " + e.getErrorCode());

                                                           System.out.println("Request ID:      " + e.getErrorRequestId());

                                                           System.out.println("Host ID:           " + e.getErrorHostId());

                                                  }

                                                   }

                                                  System.out.println("------------------------------");

                                                  request.setMarker(result.getNextMarker());

                                       }while(result.isTruncated());                

}

}

3      附录链接

OBS JAVA SDK使用方法，官网参考链接：https://support.huaweicloud.com/sdk-java-devg-obs/zh-cn_topic_0142815558.html