下载文件到本地

将指定存储桶中的文件(Object)下载到本地文件。代码中需要引用"inspurcloud/oss/OssClient.h"类库，使用InspurCloud::OSS命名空间，并初始化账号信息AccessKeyId、AccessKeySecret、Endpoint，示例代码：

        //指定目标文件所存在的桶以及目标文件(Object)名称
        std::string BucketName = "yourBucketName";
        std::string ObjectName = "yourObjectName";
        //设置下载到本地后的文件名,需包含文件路径，比如C:\\User\\Name\Desktop\\abc.txt
        std::string FileNametoSave = "yourFileName";

        //初始化资源
        InitializeSdk();
        ClientConfiguration conf;
        OssClient client(Endpoint, AccessKeyId, AccessKeySecret, conf);

        //获取文件到本地文件
        GetObjectRequest request(BucketName, ObjectName);
        request.setResponseStreamFactory([=]()
            {return std::make_shared<std::fstream>(FileNametoSave, std::ios_base::out | std::ios_base::in | std::ios_base::trunc | std::ios_base::binary); });
        auto outcome = client.GetObject(request);

        //处理结果
        if (outcome.isSuccess()) {
            std::cout << "GetObjectToFile success, ContentLength:"<<outcome.result().Metadata().ContentLength() << std::endl;
        }
        //异常处理
        else {
            std::cout << "GetObjectToFile fail" << std::endl;
            std::cout << "error code:" << outcome.error().Code() << std::endl;
            std::cout << "error message:" << outcome.error().Message() << std::endl;
            std::cout << "requestId:" << outcome.error().RequestId() << std::endl;
            ShutdownSdk();
            return -1;
        }

        //释放资源
        ShutdownSdk();