文件 AWS 開發套件範例 GitHub 儲存庫中有更多可用的 [AWS SDK 範例](https://github.com/awsdocs/aws-doc-sdk-examples)。

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。

# `HeadObject` 搭配 AWS SDK 使用
<a name="s3-directory-buckets_example_s3-directory-buckets_HeadObject_section"></a>

以下程式碼範例顯示如何使用 `HeadObject`。

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#### [ Java ]

**SDK for Java 2.x**  
 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](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javav2/example_code/s3/src/main/java/com/example/s3/directorybucket#code-examples)中設定和執行。
取得目錄儲存貯體中物件的中繼資料。  

```
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.s3.S3Client;
import software.amazon.awssdk.services.s3.model.HeadObjectRequest;
import software.amazon.awssdk.services.s3.model.HeadObjectResponse;
import software.amazon.awssdk.services.s3.model.S3Exception;

import java.nio.file.Path;

import static com.example.s3.util.S3DirectoryBucketUtils.createDirectoryBucket;
import static com.example.s3.util.S3DirectoryBucketUtils.createS3Client;
import static com.example.s3.util.S3DirectoryBucketUtils.deleteAllObjectsInDirectoryBucket;
import static com.example.s3.util.S3DirectoryBucketUtils.deleteDirectoryBucket;
import static com.example.s3.util.S3DirectoryBucketUtils.getFilePath;
import static com.example.s3.util.S3DirectoryBucketUtils.putDirectoryBucketObject;

    /**
     * Retrieves metadata for an object in the specified S3 directory bucket.
     *
     * @param s3Client   The S3 client used to interact with S3
     * @param bucketName The name of the directory bucket
     * @param objectKey  The key (name) of the object to retrieve metadata for
     * @return True if the object exists, false otherwise
     */
    public static boolean headDirectoryBucketObject(S3Client s3Client, String bucketName, String objectKey) {
        logger.info("Retrieving metadata for object: {} from bucket: {}", objectKey, bucketName);

        try {
            // Create a HeadObjectRequest
            HeadObjectRequest headObjectRequest = HeadObjectRequest.builder()
                    .bucket(bucketName)
                    .key(objectKey)
                    .build();

            // Retrieve the object metadata
            HeadObjectResponse response = s3Client.headObject(headObjectRequest);
            logger.info("Amazon S3 object: \"{}\" found in bucket: \"{}\" with ETag: \"{}\"", objectKey, bucketName,
                    response.eTag());
            logger.info("Content-Type: {}", response.contentType());
            logger.info("Content-Length: {}", response.contentLength());
            logger.info("Last Modified: {}", response.lastModified());
            return true;

        } catch (S3Exception e) {
            logger.error("Failed to retrieve object metadata: {} - Error code: {}", e.awsErrorDetails().errorMessage(),
                    e.awsErrorDetails().errorCode(), e);
            return false;
        }
    }
```
+  如需 API 詳細資訊，請參閱*《AWS SDK for Java 2.x API 參考》*中的 [HeadObject](https://docs.aws.amazon.com/goto/SdkForJavaV2/s3-2006-03-01/HeadObject)。

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