IBM Cloud Object Storage Java Client - IllegalArgument exception

I'm following sample provided here https://console.bluemix.net/docs/services/cloud-object-storage/libraries/java.html#java

Created the following code:

SDKGlobalConfiguration.IAM_ENDPOINT = "https://iam.bluemix.net/oidc/token";

String bucketName = "mybucket_name";
String api_key = "api_key_taken_fro_the_service_credential_json";
String service_instance_id = "service_id_taken_from_the_bucket_policies_page";
String endpoint_url = "http://s3.mel01.objectstorage.softlayer.net";
String location = "mel01";

System.out.println("Current time: " + new Timestamp(System.currentTimeMillis()).toString());
_cos = createClient(api_key, service_instance_id, endpoint_url, location);
listObjects(bucketName, _cos);
listBuckets(_cos);

the listObjects and listBuckets are exact c&p from that referred page.

I'm getting Invalid argument exception, as follows:

Listing objects in bucket mybucket_name
[INFO    ] FFDC1015I: An FFDC Incident has been created: "com.ibm.cloud.objectstorage.services.s3.model.AmazonS3Exception: Invalid Argument (Service: Amazon S3; Status Code: 400; Error Code: InvalidArgument; Request ID: 3bb36c4c-8de4-4f39-98f4-a1bfd3aa8972), S3 Extended Request ID: null com.ibm.ws.webcontainer.servlet.ServletWrapper.init 181" at ffdc_18.04.12_13.02.15.0.log
[ERROR   ] SRVE0271E: Uncaught init() exception created by servlet [gas.servlet.BlmxS3Servlet] in application [s3]: com.ibm.cloud.objectstorage.services.s3.model.AmazonS3Exception: Invalid Argument (Service: Amazon S3; Status Code: 400; Error Code: InvalidArgument; Request ID: 3bb36c4c-8de4-4f39-98f4-a1bfd3aa8972), S3 Extended Request ID: null
    at com.ibm.cloud.objectstorage.http.AmazonHttpClient$RequestExecutor.handleErrorResponse(AmazonHttpClient.java:1588)
    at com.ibm.cloud.objectstorage.http.AmazonHttpClient$RequestExecutor.executeOneRequest(AmazonHttpClient.java:1258)
    at com.ibm.cloud.objectstorage.http.AmazonHttpClient$RequestExecutor.executeHelper(AmazonHttpClient.java:1030)
    at com.ibm.cloud.objectstorage.http.AmazonHttpClient$RequestExecutor.doExecute(AmazonHttpClient.java:742)
    at com.ibm.cloud.objectstorage.http.AmazonHttpClient$RequestExecutor.executeWithTimer(AmazonHttpClient.java:716)
    at com.ibm.cloud.objectstorage.http.AmazonHttpClient$RequestExecutor.execute(AmazonHttpClient.java:699)
    at com.ibm.cloud.objectstorage.http.AmazonHttpClient$RequestExecutor.access$500(AmazonHttpClient.java:667)
    at com.ibm.cloud.objectstorage.http.AmazonHttpClient$RequestExecutionBuilderImpl.execute(AmazonHttpClient.java:649)
    at com.ibm.cloud.objectstorage.http.AmazonHttpClient.execute(AmazonHttpClient.java:513)
    at com.ibm.cloud.objectstorage.services.s3.AmazonS3Client.invoke(AmazonS3Client.java:3635)
    at com.ibm.cloud.objectstorage.services.s3.AmazonS3Client.invoke(AmazonS3Client.java:3582)
    at com.ibm.cloud.objectstorage.services.s3.AmazonS3Client.invoke(AmazonS3Client.java:3576)
    at com.ibm.cloud.objectstorage.services.s3.AmazonS3Client.listObjects(AmazonS3Client.java:761)
    at gas.servlet.BlmxS3Servlet.listObjects(BlmxS3Servlet.java:94)
    at gas.servlet.BlmxS3Servlet.init(BlmxS3Servlet.java:63)
    at javax.servlet.GenericServlet.init(GenericServlet.java:244)
    at [internal classes]

What argument might be invalid? No clue from the log nor ffdc.

UPDATE
The bucket name is correct, otherwise I'm getting:

[ERROR   ] SRVE0271E: Uncaught init() exception created by servlet [gas.servlet.BlmxS3Servlet] in application [s3]: com.ibm.cloud.objectstorage.services.s3.model.AmazonS3Exception: The specified bucket does not exist. (Service: Amazon S3; Status Code: 404; Error Code: NoSuchBucket; Request ID: bf299e50-1aac-4af7-89df-188eb4b7c60f), S3 Extended Request ID: null

Solution

There were several issues during configuring this:

1) You need to create credential with additional properties of {"HMAC":true}

2) For the configuration use:

apikey - apikey entry from the credential
service_instance_id - this is a bit misleading - as it is your Object servcie name, not id - in my case it was string Cloud Object Storage-abc
endpoint_url - bucket endpoint - in my case http://s3.mel01.objectstorage.softlayer.net - make sure that it is https and that you imported certificates to your truststore.

Then is should work. Listing buckets is not working for me still due to "Access Denied", so I have to check the permissions for the service ID.