Este tópico descreve como usar o kit de desenvolvimento de software (SDK) do OSS para C++ para realizar operações comuns, como criar buckets, fazer upload e baixar arquivos.
Nota
No código de exemplo, conf é uma instância de ClientConfiguration, a classe de configuração do OssClient. Use essa classe para configurar parâmetros como proxy, tempo limite de conexão e número máximo de conexões. Para mais informações, consulte Initialization (C++ SDK).
Criar um bucket
Um bucket é um namespace global no OSS que funciona como contêiner para armazenar arquivos.
Nota
Para mais informações sobre as convenções de nomenclatura de buckets, consulte Basic Concepts. Para obter detalhes sobre como obter um endpoint, consulte Regions and Endpoints.
O código a seguir mostra como criar um bucket chamado examplebucket.
#include <alibabacloud/oss/OssClient.h>
using namespace AlibabaCloud::OSS;
int main(void)
{
/* Initialize OSS account information. */
/* Set yourEndpoint to the Endpoint of the region where the bucket is located. For example, if the bucket is in the China (Hangzhou) region, set the Endpoint to https://oss-cn-hangzhou.aliyuncs.com. */
std::string Endpoint = "yourEndpoint";
/* Set yourRegion to the ID of the region where the bucket is located. For example, if the bucket is in the China (Hangzhou) region, set the Region to cn-hangzhou. */
std::string Region = "yourRegion";
/* Specify the bucket name, for example, examplebucket. */
std::string BucketName = "examplebucket";
/* Initialize network resources. */
InitializeSdk();
ClientConfiguration conf;
conf.signatureVersion = SignatureVersionType::V4;
/* Obtain access credentials from environment variables. Before you run the sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are configured. */
auto credentialsProvider = std::make_shared<EnvironmentVariableCredentialsProvider>();
OssClient client(Endpoint, credentialsProvider, conf);
client.SetRegion(Region);
/* Specify the name, storage class, and access control list (ACL) for the new bucket. */
CreateBucketRequest request(BucketName, StorageClass::IA, CannedAccessControlList::PublicReadWrite);
/* Create the bucket. */
auto outcome = client.CreateBucket(request);
if (!outcome.isSuccess()) {
/* Handle exceptions. */
std::cout << "CreateBucket fail" <<
",code:" << outcome.error().Code() <<
",message:" << outcome.error().Message() <<
",requestId:" << outcome.error().RequestId() << std::endl;
return -1;
}
/* Release network resources. */
ShutdownSdk();
return 0;
}Fazer upload de um arquivo
O código a seguir mostra como fazer upload de um arquivo para o OSS.
#include <alibabacloud/oss/OssClient.h>
using namespace AlibabaCloud::OSS;
int main(void)
{
/* Initialize OSS account information. */
/* Set yourEndpoint to the Endpoint of the region where the bucket is located. For example, if the bucket is in the China (Hangzhou) region, set the Endpoint to https://oss-cn-hangzhou.aliyuncs.com. */
std::string Endpoint = "yourEndpoint";
/* Set yourRegion to the ID of the region where the bucket is located. For example, if the bucket is in the China (Hangzhou) region, set the Region to cn-hangzhou. */
std::string Region = "yourRegion";
/* Specify the bucket name, for example, examplebucket. */
std::string BucketName = "examplebucket";
/* Specify the full path of the file, for example, exampledir/exampleobject.txt. The full path cannot contain the bucket name. */
std::string ObjectName = "exampledir/exampleobject.txt";
/* Initialize network resources. */
InitializeSdk();
ClientConfiguration conf;
conf.signatureVersion = SignatureVersionType::V4;
/* Obtain access credentials from environment variables. Before you run the sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are configured. */
auto credentialsProvider = std::make_shared<EnvironmentVariableCredentialsProvider>();
OssClient client(Endpoint, credentialsProvider, conf);
client.SetRegion(Region);
/* Upload the file. */
/* Specify the full path of the local file, for example, D:\\localpath\\examplefile.txt. In this path, localpath is the local directory where the examplefile.txt file is stored. */
auto outcome = client.PutObject(BucketName, ObjectName,"D:\\localpath\\examplefile.txt");
if (!outcome.isSuccess()) {
/* Handle exceptions. */
std::cout << "PutObject fail" <<
",code:" << outcome.error().Code() <<
",message:" << outcome.error().Message() <<
",requestId:" << outcome.error().RequestId() << std::endl;
return -1;
}
/* Release network resources. */
ShutdownSdk();
return 0;
}Baixar um arquivo
O código a seguir mostra como baixar um arquivo do OSS para um arquivo local.
#include <alibabacloud/oss/OssClient.h>
#include <memory>
#include <fstream>
using namespace AlibabaCloud::OSS;
int main(void)
{
/* Initialize information about the account that is used to access OSS. */
/* Specify the endpoint of the region in which the bucket is located. For example, if the bucket is located in the China (Hangzhou) region, set the endpoint to https://oss-cn-hangzhou.aliyuncs.com. */
std::string Endpoint = "yourEndpoint";
/* Specify the region in which the bucket is located. For example, if the bucket is located in the China (Hangzhou) region, set the region to cn-hangzhou. */
std::string Region = "yourRegion";
/* Specify the name of the bucket. Example: examplebucket. */
std::string BucketName = "examplebucket";
/* Specify the full path of the object. Do not include the bucket name in the full path. Example: exampledir/exampleobject.txt. */
std::string ObjectName = "exampledir/exampleobject.txt";
/* Download the object as a local file named examplefile.txt and save the file to D:\\localpath. If a file that has the same name already exists in the specified path, the downloaded object overwrites the file. Otherwise, the downloaded object is saved in the path. */
/* If you do not specify the path of the local file, the downloaded object is saved to the path of the project to which the sample program belongs. */
std::string FileNametoSave = "D:\\localpath\\examplefile.txt";
/* Initialize resources such as network resources. */
InitializeSdk();
ClientConfiguration conf;
conf.signatureVersion = SignatureVersionType::V4;
/* Obtain access credentials from environment variables. Before you run the sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are configured. */
auto credentialsProvider = std::make_shared<EnvironmentVariableCredentialsProvider>();
OssClient client(Endpoint, credentialsProvider, conf);
client.SetRegion(Region);
/* Download the object as a local file. */
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);
if (outcome.isSuccess()) {
std::cout << "GetObjectToFile success" << outcome.result().Metadata().ContentLength() << std::endl;
}
else {
/* Handle exceptions. */
std::cout << "GetObjectToFile fail" <<
",code:" << outcome.error().Code() <<
",message:" << outcome.error().Message() <<
",requestId:" << outcome.error().RequestId() << std::endl;
return -1;
}
/* Release resources such as network resources. */
ShutdownSdk();
return 0;
}Listar arquivos
O código a seguir mostra como listar os arquivos em um bucket. Por padrão, são listados no máximo 100 arquivos.
#include <alibabacloud/oss/OssClient.h>
using namespace AlibabaCloud::OSS;
int main(void)
{
/* Initialize OSS account information. */
/* Set yourEndpoint to the Endpoint of the region where the bucket is located. For example, if the bucket is in the China (Hangzhou) region, set the Endpoint to https://oss-cn-hangzhou.aliyuncs.com. */
std::string Endpoint = "yourEndpoint";
/* Set yourRegion to the ID of the region where the bucket is located. For example, if the bucket is in the China (Hangzhou) region, set the Region to cn-hangzhou. */
std::string Region = "yourRegion";
/* Specify the bucket name, for example, examplebucket. */
std::string BucketName = "examplebucket";
/* Initialize network resources. */
InitializeSdk();
ClientConfiguration conf;
conf.signatureVersion = SignatureVersionType::V4;
/* Obtain access credentials from environment variables. Before you run the sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are configured. */
auto credentialsProvider = std::make_shared<EnvironmentVariableCredentialsProvider>();
OssClient client(Endpoint, credentialsProvider, conf);
client.SetRegion(Region);
/* List the files. */
ListObjectsRequest request(BucketName);
auto outcome = client.ListObjects(request);
if (!outcome.isSuccess()) {
/* Handle exceptions. */
std::cout << "ListObjects fail" <<
",code:" << outcome.error().Code() <<
",message:" << outcome.error().Message() <<
",requestId:" << outcome.error().RequestId() << std::endl;
return -1;
}
else {
for (const auto& object : outcome.result().ObjectSummarys()) {
std::cout << "object"<<
",name:" << object.Key() <<
",size:" << object.Size() <<
",last modified time:" << object.LastModified() << std::endl;
}
}
/* Release network resources. */
ShutdownSdk();
return 0;
}Excluir um arquivo
O código a seguir mostra como excluir um arquivo específico.
#include <alibabacloud/oss/OssClient.h>
using namespace AlibabaCloud::OSS;
int main(void)
{
/* Initialize OSS account information. */
/* Set yourEndpoint to the Endpoint of the region where the bucket is located. For example, if the bucket is in the China (Hangzhou) region, set the Endpoint to https://oss-cn-hangzhou.aliyuncs.com. */
std::string Endpoint = "yourEndpoint";
/* Set yourRegion to the ID of the region where the bucket is located. For example, if the bucket is in the China (Hangzhou) region, set the Region to cn-hangzhou. */
std::string Region = "yourRegion";
/* Specify the bucket name, for example, examplebucket. */
std::string BucketName = "examplebucket";
/* Specify the full path of the file, for example, exampledir/exampleobject.txt. The full path cannot contain the bucket name. */
std::string ObjectName = "exampledir/exampleobject.txt";
/* Initialize network resources. */
InitializeSdk();
ClientConfiguration conf;
conf.signatureVersion = SignatureVersionType::V4;
/* Obtain access credentials from environment variables. Before you run the sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are configured. */
auto credentialsProvider = std::make_shared<EnvironmentVariableCredentialsProvider>();
OssClient client(Endpoint, credentialsProvider, conf);
client.SetRegion(Region);
DeleteObjectRequest request(BucketName, ObjectName);
/* Delete the file. */
auto outcome = client.DeleteObject(request);
if (!outcome.isSuccess()) {
/* Handle exceptions. */
std::cout << "DeleteObject fail" <<
",code:" << outcome.error().Code() <<
",message:" << outcome.error().Message() <<
",requestId:" << outcome.error().RequestId() << std::endl;
return -1;
}
/* Release network resources. */
ShutdownSdk();
return 0;
}Referências
Para obter o código de exemplo completo, consulte o exemplo no GitHub.
Para mais informações sobre a operação da API para criar um bucket, consulte PutBucket.
Para mais informações sobre a operação da API para fazer upload de um arquivo, consulte PutObject.
Para mais informações sobre a operação da API para baixar um arquivo, consulte GetObject.
Para mais informações sobre a operação da API para listar arquivos, consulte GetBucket (ListObjects).
Para mais informações sobre a operação da API para excluir um arquivo, consulte DeleteObject.