Download objects from CloudBox

You can download objects only by using the Alibaba Cloud OSS Java SDK version 3.15.0 or later.

All requests use Signature Version 4 (V4) and require a CloudBox ID in addition to the standard endpoint and region.

package com.aliyun.oss.demo;

import com.aliyun.oss.ClientException;
import com.aliyun.oss.OSS;
import com.aliyun.oss.common.auth.*;
import com.aliyun.oss.OSSClientBuilder;
import com.aliyun.oss.OSSException;
import com.aliyun.oss.model.GetObjectRequest;
import java.io.File;
import com.aliyun.oss.common.auth.DefaultCredentialProvider;
import com.aliyun.oss.common.comm.SignVersion;
import com.aliyun.oss.ClientBuilderConfiguration;
import com.aliyun.oss.common.auth.CredentialsProviderFactory;
import com.aliyun.oss.common.auth.EnvironmentVariableCredentialsProvider;

public class Demo {

    public static void main(String[] args) throws Exception {
        // Specify the data endpoint of the OSS on CloudBox bucket.
        String endpoint = "https://cb-f8z7yvzgwfkl9q0h****.cn-hangzhou.oss-cloudbox.aliyuncs.com";
        // Obtain access credentials from environment variables. Before you run this 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 OSS on CloudBox bucket. For example, examplebucket.
        String bucketName = "examplebucket";
        // Specify the region where the OSS on CloudBox bucket is located.
        String region = "cn-hangzhou";
        // Specify the ID of the CloudBox.
        String cloudBoxId = "cb-f8z7yvzgwfkl9q0h****";
        // Specify the full path of the object, excluding the bucket name. For example, exampledir/exampleobject.txt.
        String objectName = "exampledir/exampleobject.txt";
        // Specify the local file path to save the downloaded object.
        String pathName = "D:\\localpath\\examplefile.txt";

        // Create an OSSClient instance using Signature Version 4 (V4).
        // Call shutdown() to release resources when the client is no longer needed.
        ClientBuilderConfiguration conf = new ClientBuilderConfiguration();
        conf.setSignatureVersion(SignVersion.V4);
        OSS ossClient = OSSClientBuilder.create()
                .endpoint(endpoint)
                .credentialsProvider(new DefaultCredentialProvider(credentialsProvider.getCredentials()))
                .clientConfiguration(conf)
                .region(region)
                .cloudBoxId(cloudBoxId)
                .build();

        try {
            // Download the object to the specified local file.
            // If the file exists, it is overwritten. If it does not exist, a new file is created.
            // If you do not specify a local path, the file is saved to the path of the project to which the sample program belongs.
            ossClient.getObject(new GetObjectRequest(bucketName, objectName), new File(pathName));
        } catch (OSSException oe) {
            System.out.println("OSS rejected the request.");
            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("Client failed to communicate with OSS.");
            System.out.println("Error Message:" + ce.getMessage());
        } finally {
            if (ossClient != null) {
                ossClient.shutdown();
            }
        }
    }
}

For more information about how to perform a simple download using ossutil, see cp (Download files).

If your application requires custom request handling, call the REST API directly. You must sign requests manually. For more information, see GetObject.