JavaSDK實現資料流分區上傳的代碼範例 - Object Storage Service

本文提供資料流分區上傳的程式碼範例。

注意事項

本文以華東1（杭州）外網Endpoint為例。如果您希望通過與OSS同地區的其他阿里雲產品訪問OSS，請使用內網Endpoint。關於OSS支援的Region與Endpoint的對應關係，請參見OSS地區和訪問網域名稱。
本文以從環境變數讀取存取憑證為例。如何配置訪問憑證，請參見配置訪問憑證。
本文以OSS網域名稱建立OSSClient為例。如果您希望通過自訂網域名、STS等方式建立OSSClient，請參見配置用戶端。
要完成分區上傳的完整流程，包括InitiateMultipartUpload、UploadPart、CompleteMultipartUpload，您必須有oss:PutObject許可權。具體操作，請參見RAM Policy常見樣本。

範例程式碼

以下是資料流分區上傳的代碼範例。

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.List;

import com.aliyun.oss.*;
import com.aliyun.oss.common.auth.CredentialsProviderFactory;
import com.aliyun.oss.common.auth.EnvironmentVariableCredentialsProvider;
import com.aliyun.oss.common.comm.SignVersion;
import com.aliyun.oss.internal.Mimetypes;
import com.aliyun.oss.model.*;

public class MultipartUploadforStream {
    public static void main(String[] args) throws Exception {
        // Endpoint以華東1（杭州）為例，其他Region請按實際情況填寫。
        String endpoint = "https://oss-cn-hangzhou.aliyuncs.com";

        // 從環境變數中擷取訪問憑證。運行本程式碼範例之前，請確保已設定環境變數OSS_ACCESS_KEY_ID和OSS_ACCESS_KEY_SECRET。
        EnvironmentVariableCredentialsProvider credentialsProvider = CredentialsProviderFactory.newEnvironmentVariableCredentialsProvider();

        // 填寫Bucket名稱，例如examplebucket。
        String bucketName = "examplebucket";

        // 填寫Object完整路徑，例如exampledir/exampleobject.txt。Object完整路徑中不能包含Bucket名稱。
        String objectName = "exampledir/exampleobject.txt";

        // 待上傳本地檔案路徑。
        String filePath = "/Users/localFilePath/example.txt";

        // 填寫Bucket所在地區。以華東1（杭州）為例，Region填寫為cn-hangzhou。
        String region = "cn-hangzhou";

        // 建立OSSClient執行個體。
        // 當OSSClient執行個體不再使用時，調用shutdown方法以釋放資源。
        ClientBuilderConfiguration clientBuilderConfiguration = new ClientBuilderConfiguration();
        clientBuilderConfiguration.setSignatureVersion(SignVersion.V4);
        OSS ossClient = OSSClientBuilder.create()
                .endpoint(endpoint)
                .credentialsProvider(credentialsProvider)
                .clientConfiguration(clientBuilderConfiguration)
                .region(region)
                .build();

        try {
            // 建立InitiateMultipartUploadRequest對象。
            InitiateMultipartUploadRequest request = new InitiateMultipartUploadRequest(bucketName, objectName);

            ObjectMetadata metadata = new ObjectMetadata();
            if (metadata.getContentType() == null) {
                metadata.setContentType(Mimetypes.getInstance().getMimetype(new File(filePath), objectName));
            }
            System.out.println("Content-Type: " + metadata.getContentType());
            request.setObjectMetadata(metadata);

            // 初始化分區上傳，返回uploadId。
            InitiateMultipartUploadResult upresult = ossClient.initiateMultipartUpload(request);
            String uploadId = upresult.getUploadId();

            // partETags是PartETag的集合。
            List<PartETag> partETags = new ArrayList<>();

            // 計算檔案分區數量。
            File sampleFile = new File(filePath);
            long fileLength = sampleFile.length();
            final long partSize = 5 * 1024 * 1024L; // 每個分區大小為5MB。

            // 遍曆分區並上傳。
            try (FileInputStream instream = new FileInputStream(sampleFile)) {
                byte[] buffer = new byte[8192]; // 設定緩衝區
                long remaining = fileLength;
                int partNumber = 1;

                while (remaining > 0) {
                    ByteArrayOutputStream baos = new ByteArrayOutputStream();
                    long bytesToRead = Math.min(partSize, remaining);

                    int bytesRead;
                    long totalRead = 0;
                    while (totalRead < bytesToRead && (bytesRead = instream.read(buffer)) > 0) {
                        baos.write(buffer, 0, bytesRead);
                        totalRead += bytesRead;
                    }

                    // 構造分區流
                    InputStream partStream = new ByteArrayInputStream(baos.toByteArray());

                    UploadPartRequest uploadPartRequest = new UploadPartRequest();
                    uploadPartRequest.setBucketName(bucketName);
                    uploadPartRequest.setKey(objectName);
                    uploadPartRequest.setUploadId(uploadId);
                    uploadPartRequest.setInputStream(partStream);
                    uploadPartRequest.setPartSize(totalRead);
                    uploadPartRequest.setPartNumber(partNumber++);

                    UploadPartResult uploadPartResult = ossClient.uploadPart(uploadPartRequest);
                    partETags.add(uploadPartResult.getPartETag());

                    remaining -= totalRead;
                }
            }

            // 建立CompleteMultipartUploadRequest對象。
            CompleteMultipartUploadRequest completeMultipartUploadRequest =
                    new CompleteMultipartUploadRequest(bucketName, objectName, uploadId, partETags);

            // 完成分區上傳。
            CompleteMultipartUploadResult completeMultipartUploadResult = ossClient.completeMultipartUpload(completeMultipartUploadRequest);
            System.out.println("上傳成功，ETag：" + completeMultipartUploadResult.getETag());
        } 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 a 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 {
            // 關閉OSSClient。
            if (ossClient != null) {
                ossClient.shutdown();
            }
        }
    }
}

Object Storage Service：JavaSDK實現資料流分區上傳的代碼範例

注意事項

範例程式碼

相關文檔