Amazon S3 Java获取上传 ID

在使用Amazon S3 Java SDK上传文件时，可以通过在`PutObjectResult`对象中获取上传ID。示例如下：

import com.amazonaws.services.s3.AmazonS3;
import com.amazonaws.services.s3.AmazonS3ClientBuilder;
import com.amazonaws.services.s3.model.PutObjectRequest;
import com.amazonaws.services.s3.model.PutObjectResult;

public class S3UploadExample {
    private static final String BUCKET_NAME = "your-bucket-name";
    private static final String OBJECT_KEY = "your-object-key";
    private static final String FILE_PATH = "path-to-your-file";

    public static void main(String[] args) {
        AmazonS3 s3Client = AmazonS3ClientBuilder.defaultClient();

        PutObjectRequest request = new PutObjectRequest(BUCKET_NAME, OBJECT_KEY, new File(FILE_PATH));
        PutObjectResult result = s3Client.putObject(request);

        String uploadId = result.getUploadId();
        System.out.println("Upload ID: " + uploadId);
    }
}

在上面的示例中，`result.getUploadId()`方法将返回上传ID。请注意，上传ID仅在使用分段上传时才会返回。如果您使用的是简单上传，则不会有上传ID返回。