Minio Cannot list Objects in a bucket using JAVA SDK Client, getting error Non-XML response from server. Response code: 403

[harshit149]

I am trying to access objects of a bucket via Minio JAVA SdK Client and I am getting following error
io.minio.errors.InvalidResponseException: Non-XML response from server. Response code: 403, Content-Type: text/xml; charset=utf-8, body:

This is my code snippet
// Lists objects information.
            Iterable<Result<Item>> results = minioClient.listObjects(
                    ListObjectsArgs.builder().bucket("bucket-name").build());
            for(Result<Item> result : results) {
                Item item = result.get();
                System.out.println("Object:"+ item.objectName());
            }

What after debugging I am suspecting is URL is not formed correctly by SDK and there is forward slash miss after bucket name in URL.

[lexakimov]

Hi. I have the same "Non-XML response from server" error. We use our own S3 implementation, the problem is in the content-type header. Our server returns Content-Type: text/xml; charset=utf-8 but the client expects Content-Type: application/xml:
In my case, error happens here:

https://github.com/minio/minio-java/blob/master/api/src/main/java/io/minio/S3Base.java#L693

                String contentType = response.headers().get("content-type");
                if (!method.equals(Method.HEAD)
                    && (contentType == null
                        || !Arrays.asList(contentType.split(";")).contains("application/xml"))) {
                  if (response.code() == 304 && response.body().contentLength() == 0) {
                    completableFuture.completeExceptionally(
                        new ServerException(

BTW https://docs.aws.amazon.com/AmazonS3/latest/API/ErrorResponses.html#RESTErrorResponses says:

Content-Type: application/xml

[harshit149]

@lexakimov do you know if there is any stable version where this still works?

[balamurugana]

As per the S3 specification, any failed call should return Error XML. minio-java returns Non-XML response if the server violates the spec. Few things you need to check

1. Check your server is returning proper Error XML
2. Check your proxy if you use
3. Check you are using correct port to connect to S3 server.

[lexakimov]

@harshit149 no, I've made a workaround for now by handling the InvalidResponseException. The developers of our S3 storage have confirmed that the error is on their side (wrong header), not in client.

[lexakimov]

@balamurugana it returns valid xml, but header Content-Type is wrong (client expects application/xml )

---------START-HTTP---------
GET ***** HTTP/1.1
Host: *****
Accept-Encoding: identity
User-Agent: MinIO (Linux; amd64) minio-java/8.5.17
Content-MD5: 1B2M2Y8AsgTpgAmY7PhCfg==
x-amz-content-sha256: UNSIGNED-PAYLOAD
x-amz-date: 20250320T072856Z
Authorization: ██

HTTP/1.1 404
Date: Thu, 20 Mar 2025 07:28:57 GMT
Content-Length: 135
Content-Type: text/xml; charset=utf-8

<?xml version="1.0" encoding="UTF-8"?>
<Error>
  <Code>NoSuchKey</Code>
  <Message>The specified key does not exist.</Message>
</Error>
----------END-HTTP----------

[harshit149]

Thank you for detailed response and findings.
@lexakimov how can I fix this at server side?

[gyanicit]

I have issue similar to @harshit149 the actual cause is how the URL is being constructed.

URL Constructed by MinIO Client: https://abc.com/myBucket?list-type=2&prefix=t&max-keys=1000&encoding-type=url&delimiter=/

@balamurugana this URL is invalid for me even I am not able to make call via Postman, but after a small tweek I am able to make call on same url via postman.

tweeked URL: https://abc.com/myBucket/?list-type=2&prefix=t&max-keys=1000&encoding-type=url&delimiter=

For better understanding what I did is added slash after bucket name like this "myBucket/". I am not sure in the MinIO URL if you observe the slash is being added but at the very last just after delimiter like this "delimiter=/"

I have created client and the code to access files inside bucket like below

// 1. Create MinIO Client
            MinioClient minioClient = MinioClient.builder()
                    .endpoint("https://abc.com") // Change to your MinIO server
                    .credentials("accessKey", "secretKey") // Use your credentials
                    .region("us-east-1")
                    .build();


Iterable<Result<Item>> results = minioClient.listObjects(
                    ListObjectsArgs.builder()
                            .bucket("myBucket")
                            .maxKeys(1000)
                            .prefix("t")
                            .recursive(true)
                            .build());
            for (Result<Item> result : results) {
                Item item = result.get();
                System.out.println(item.objectName());
            }

[lexakimov]

@harshit149 in my case it was necessary to catch the "no such key found"

before fix i did it this way:

e is ErrorResponseException && e.errorResponse().code().equals("NoSuchKey")

as temporary workaround i added another condition:

e is InvalidResponseException && (e.message?.contains("NoSuchKey") == true || e.httpTrace().contains("NoSuchKey")

[balamurugana]

@balamurugana it returns valid xml, but header Content-Type is wrong (client expects application/xml )

---------START-HTTP---------
GET ***** HTTP/1.1
Host: *****
Accept-Encoding: identity
User-Agent: MinIO (Linux; amd64) minio-java/8.5.17
Content-MD5: 1B2M2Y8AsgTpgAmY7PhCfg==
x-amz-content-sha256: UNSIGNED-PAYLOAD
x-amz-date: 20250320T072856Z
Authorization: ██

HTTP/1.1 404
Date: Thu, 20 Mar 2025 07:28:57 GMT
Content-Length: 135
Content-Type: text/xml; charset=utf-8

<?xml version="1.0" encoding="UTF-8"?>
<Error>
  <Code>NoSuchKey</Code>
  <Message>The specified key does not exist.</Message>
</Error>
----------END-HTTP----------

@lexakimov It is server side problem. What object storage service are you using?

[balamurugana]

I have issue similar to @harshit149 the actual cause is how the URL is being constructed.

URL Constructed by MinIO Client: https://abc.com/myBucket?list-type=2&prefix=t&max-keys=1000&encoding-type=url&delimiter=/

@balamurugana this URL is invalid for me even I am not able to make call via Postman, but after a small tweek I am able to make call on same url via postman.

tweeked URL: https://abc.com/myBucket/?list-type=2&prefix=t&max-keys=1000&encoding-type=url&delimiter=

For better understanding what I did is added slash after bucket name like this "myBucket/". I am not sure in the MinIO URL if you observe the slash is being added but at the very last just after delimiter like this "delimiter=/"

I have created client and the code to access files inside bucket like below

// 1. Create MinIO Client
            MinioClient minioClient = MinioClient.builder()
                    .endpoint("https://abc.com") // Change to your MinIO server
                    .credentials("accessKey", "secretKey") // Use your credentials
                    .region("us-east-1")
                    .build();


Iterable<Result<Item>> results = minioClient.listObjects(
                    ListObjectsArgs.builder()
                            .bucket("myBucket")
                            .maxKeys(1000)
                            .prefix("t")
                            .recursive(true)
                            .build());
            for (Result<Item> result : results) {
                Item item = result.get();
                System.out.println(item.objectName());
            }

@gyanicit This is server side issue. There is no need to add /. What is your server?

[harshit149]

@balamurugana in my case we are using minio object storage service, how can we fix this?

[balamurugana]

@balamurugana in my case we are using minio object storage service, how can we fix this?

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