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Object Storage Service:Gerenciar links simbólicos com o OSS SDK for Java 1.0

Última atualização: Jul 03, 2026

Os links simbólicos funcionam como atalhos de arquivo no Windows e permitem acessar rapidamente os objetos associados no Object Storage Service (OSS).

Observações de uso

  • Este tópico utiliza o endpoint público da região China (Hangzhou). Para acessar o OSS a partir de outros serviços da Alibaba Cloud na mesma região, use um endpoint interno. Para obter detalhes sobre as regiões e endpoints compatíveis, consulte Regiões e endpoints.

  • As credenciais de acesso neste tópico são obtidas de variáveis de ambiente. Para mais informações, consulte Configurar credenciais de acesso.

  • Este tópico demonstra a criação de uma instância OSSClient com um endpoint do OSS. Para outras configurações, como uso de domínio personalizado ou autenticação com credenciais do Security Token Service (STS), consulte Configuração do cliente.

  • A criação de um link simbólico exige a permissão oss:PutObject. A consulta exige a permissão oss:GetObject. Para mais informações, consulte Conceder uma política personalizada.

Crie um link simbólico

O código de exemplo a seguir mostra como criar um link simbólico:

import com.aliyun.oss.*;
import com.aliyun.oss.common.auth.*;
import com.aliyun.oss.common.comm.SignVersion;
import com.aliyun.oss.model.*;

public class Demo {
    public static void main(String[] args) throws Exception {
        // In this example, the endpoint of the China (Hangzhou) region is used. Specify your actual endpoint. 
        String endpoint = "https://oss-cn-hangzhou.aliyuncs.com";
        // 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. 
        EnvironmentVariableCredentialsProvider credentialsProvider = CredentialsProviderFactory.newEnvironmentVariableCredentialsProvider();
        // Specify the name of the bucket. Example: examplebucket. 
        String bucketName = "examplebucket";
        // Specify the name of the symbolic link that you want to create. 
        String symLink = "yourSymLink";
        // Specify the name of the object to which you want the symbolic link to point. 
        String destinationObjectName = "yourDestinationObjectName";
        // 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.
        String region = "cn-hangzhou";

        // Create an OSSClient instance. 
        // Call the shutdown method to release resources when the OSSClient is no longer in use.
        ClientBuilderConfiguration clientBuilderConfiguration = new ClientBuilderConfiguration();
        clientBuilderConfiguration.setSignatureVersion(SignVersion.V4);        
        OSS ossClient = OSSClientBuilder.create()
        .endpoint(endpoint)
        .credentialsProvider(credentialsProvider)
        .clientConfiguration(clientBuilderConfiguration)
        .region(region)               
        .build();

        try {
            // Create metadata for the object that you want to upload. 
            ObjectMetadata metadata = new ObjectMetadata();
            metadata.setContentType("text/plain");
            // Set the property parameter for the user metadata to property-value. 
            metadata.addUserMetadata("property", "property-value");

            // Specify whether to overwrite the object that has the same name as the symbolic link. 
            // metadata.setHeader("x-oss-forbid-overwrite", "true");
            // Specify the access control list (ACL) of the object. 
            // metadata.setHeader(OSSHeaders.OSS_OBJECT_ACL, CannedAccessControlList.Default);
            // Specify the storage class of the object. 
            // metadata.setHeader(OSSHeaders.OSS_STORAGE_CLASS, StorageClass.Standard);

            // Create a CreateSymlinkRequest to create the symbolic link. 
            CreateSymlinkRequest createSymlinkRequest = new CreateSymlinkRequest(bucketName, symLink, destinationObjectName);

            // Configure the metadata. 
            createSymlinkRequest.setMetadata(metadata);

            // Create the symbolic link. 
            ossClient.createSymlink(createSymlinkRequest);

        } 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();
            }
        }
    }
}            

Consultar um link simbólico

A consulta de um link simbólico exige permissões de leitura sobre ele. O código de exemplo a seguir mostra como consultar um link simbólico e obter o nome do objeto de destino:

import com.aliyun.oss.*;
import com.aliyun.oss.common.auth.*;
import com.aliyun.oss.common.comm.SignVersion;
import com.aliyun.oss.model.*;

public class Demo {
    public static void main(String[] args) throws Exception {
        // In this example, the endpoint of the China (Hangzhou) region is used. Specify your actual endpoint. 
        String endpoint = "https://oss-cn-hangzhou.aliyuncs.com";
        // 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. 
        EnvironmentVariableCredentialsProvider credentialsProvider = CredentialsProviderFactory.newEnvironmentVariableCredentialsProvider();
        // Specify the name of the bucket. Example: examplebucket. 
        String bucketName = "examplebucket";
        // Specify the name of the symbolic link that you want to query. 
        String symLink = "yourSymLink";
        // 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.
        String region = "cn-hangzhou";

        // Create an OSSClient instance. 
        // Call the shutdown method to release resources when the OSSClient is no longer in use.
        ClientBuilderConfiguration clientBuilderConfiguration = new ClientBuilderConfiguration();
        clientBuilderConfiguration.setSignatureVersion(SignVersion.V4);        
        OSS ossClient = OSSClientBuilder.create()
        .endpoint(endpoint)
        .credentialsProvider(credentialsProvider)
        .clientConfiguration(clientBuilderConfiguration)
        .region(region)               
        .build();

        try {
            // Query the symbolic link and the name of the object to which the symbolic link points. 
            OSSSymlink symbolicLink = ossClient.getSymlink(bucketName, symLink);
            System.out.println(symbolicLink.getSymlink());
            System.out.println(symbolicLink.getTarget());
            System.out.println(symbolicLink.getRequestId());
        } 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();
            }
        }
    }
}          

Referências

  • Para mais informações sobre a operação de API usada para criar um link simbólico, consulte PutSymlink.

  • Para mais detalhes sobre a operação de API usada para consultar um link simbólico, consulte GetSymlink.