Any way to confirm object exist or not?

[laudukang]

I have a use case to comfirm a object exist in bucket whether or not, and I can finish the case through the following ways:

1. MinioClient#statObject, method will throw exception if object not exist, so I can know the object is not exist in minio server

2. MinioClient#getObject, method will throw exception if object not exist

Is there a better way that I can ensure a object exist in minio server whether or not?

[harshavardhana]

What you explained is the most idiomatic way. What exactly are you looking for ?

[laudukang]

@harshavardhana Sorry, I have updated the issue.

[balamurugana]

@laudukang You would need to do like below

boolean found = false;
try {
  minioClient.statObject("my-bucketname", "my-objectname");
  found = true;
} catch (ErrorResponseException e) {
  if (e.errorResponse().errorCode() != ErrorCode.NO_SUCH_OBJECT)) {
    throw e;
  }
}

if (found) {
  // Do things when object is found
} else {
  // Do things when object is not found
}

[kannappanr]

@laudukang Please close the issue, if the above reply is what you are looking for.

[vmyrsky]

This works a bit better.

catch (ErrorResponseException e) {
  ErrorCode code = e.errorResponse().errorCode();
  if (code == ErrorCode.NO_SUCH_KEY || code == ErrorCode.NO_SUCH_OBJECT) {
    // Not found
  } else {
    throw e;
  }
}

[negarnegma]

what about a folder? it throws a NO SUCH KEY exception too!

[vishrantgupta]

@balamurugana I guess there is a delete marker (at least in Go minio client, have not checked in Java), and instead of just returning true, we should check for a delete marker.

objectStats.IsDeleteMarker == false

[tabiStein]

Hello MinIO devs! After searching for the correct way to check if a MinIO object exists, I stumbled across this thread. @balamurugana suggested the following:

try {
  minioClient.statObject("my-bucketname", "my-objectname");
  found = true;
} catch (ErrorResponseException e) {
  if (e.errorResponse().errorCode() != ErrorCode.NO_SUCH_OBJECT)) {
    throw e;
  }
}

However, in the latest version of MinIO (or more specifically, since release 8.0.0) the ErrorCode enum has been deleted. (See PR #1028 ).
Is there a convenient and clean way to check the error codes without hardcoding them in my application?

Thanks!! - Tabi

[balamurugana]

It is same logic like below

try {
  StatObjectResponse stat = minioClient.statObject(StatObjectArgs.builder().bucket("my-bucketname").object("my-objectname").build());
  found = true;
} catch (ErrorResponseException e) {
  if (e.response().code() != "NoSuchKey")) {
    throw e;
  }
}

Refer https://docs.aws.amazon.com/AmazonS3/latest/API/ErrorResponses.html for error codes. If you want enum style error codes, define your own enums and use it here.

[tabiStein]

Thanks for the quick reply and the link to the error codes @balamurugana !