Check metadata of S3 objects with AWS SDK for Java 2.x

问题

I was not able to find a way to check the metadata fields of an S3 object such as the Content-Type or the Cache-Control with the AWS SDK for Java 2.x.

With the AWS SDK for Java 1.x it was as easy as this:

s3Client.getObjectMetadata("myBucket", "myfile.doc");

But I cannot see the analogous method for the newest version of the API.

回答1:

The solution is to use HeadObjectRequest and HeadObjectResponse:

HeadObjectRequest headObjectRequest = HeadObjectRequest.builder()
  .bucket(bucketName)
  .key(key)
  .build();

And then:

HeadObjectResponse headObjectResponse = s3Client.headObject(headObjectRequest);

System.out.println("This is what I need: " + headObjectResponse.contentType());

来源：https://stackoverflow.com/questions/56949135/check-metadata-of-s3-objects-with-aws-sdk-for-java-2-x