文件 AWS 開發套件範例 GitHub 儲存庫中有更多可用的 AWS SDK 範例
本文為英文版的機器翻譯版本,如內容有任何歧義或不一致之處,概以英文版為準。
檢查儲存貯體是否存在
下列程式碼範例示範如何檢查儲存貯體是否存在。
- SDK for Java 2.x
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注意
GitHub 上提供更多範例。尋找完整範例,並了解如何在 AWS 程式碼範例儲存庫
中設定和執行。 您可以使用下列
doesBucketExists
方法取代適用於 Java V1 的 SDK AmazonS3Client#doesBucketExistV2(字串) 方法。import org.slf4j.Logger; import org.slf4j.LoggerFactory; import software.amazon.awssdk.awscore.exception.AwsServiceException; import software.amazon.awssdk.http.HttpStatusCode; import software.amazon.awssdk.services.s3.S3Client; import software.amazon.awssdk.utils.Validate; public class DoesBucketExist { private static final Logger logger = LoggerFactory.getLogger(DoesBucketExist.class); public static void main(String[] args) { DoesBucketExist doesBucketExist = new DoesBucketExist(); final S3Client s3SyncClient = S3Client.builder().build(); final String bucketName = "amzn-s3-demo-bucket"; // Change to the bucket name that you want to check. boolean exists = doesBucketExist.doesBucketExist(bucketName, s3SyncClient); logger.info("Bucket exists: {}", exists); } /** * Checks if the specified bucket exists. Amazon S3 buckets are named in a global namespace; use this method to * determine if a specified bucket name already exists, and therefore can't be used to create a new bucket. * <p> * Internally this method uses the <a * href="https://sdk.amazonaws.com/java/api/latest/software/amazon/awssdk/services/s3/S3Client.html#getBucketAcl(java.util.function.Consumer)">S3Client.getBucketAcl(String)</a> * operation to determine whether the bucket exists. * <p> * This method is equivalent to the AWS SDK for Java V1's <a * href="https://docs.aws.amazon.com/AWSJavaSDK/latest/javadoc/com/amazonaws/services/s3/AmazonS3Client.html#doesBucketExistV2-java.lang.String-">AmazonS3Client#doesBucketExistV2(String)</a>. * * @param bucketName The name of the bucket to check. * @param s3SyncClient An <code>S3Client</code> instance. The method checks for the bucket in the AWS Region * configured on the instance. * @return The value true if the specified bucket exists in Amazon S3; the value false if there is no bucket in * Amazon S3 with that name. */ public boolean doesBucketExist(String bucketName, S3Client s3SyncClient) { try { Validate.notEmpty(bucketName, "The bucket name must not be null or an empty string.", ""); s3SyncClient.getBucketAcl(r -> r.bucket(bucketName)); return true; } catch (AwsServiceException ase) { // A redirect error or an AccessDenied exception means the bucket exists but it's not in this region // or we don't have permissions to it. if ((ase.statusCode() == HttpStatusCode.MOVED_PERMANENTLY) || "AccessDenied".equals(ase.awsErrorDetails().errorCode())) { return true; } if (ase.statusCode() == HttpStatusCode.NOT_FOUND) { return false; } throw ase; } } }
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如需 API 詳細資訊,請參閱《AWS SDK for Java 2.x API 參考》中的 GetBucketAcl。
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