[SalesForce] Bulk API: using Workbench InvalidSessionId (Unable to find session id)

I think you are specifying the object using the wrong name. You should be using the API name 'Statement__c' inside the object tag for custom objects, like:

<?xml version="1.0" encoding="UTF-8"?>
<jobInfo  xmlns="http://www.force.com/2009/06/asyncapi/dataload">
  <operation>insert</operation>
  <object>Statement__c</object>
  <contentType>CSV</contentType>
</jobInfo>

Also, the API name probably has a double underscore.

It seems that the Bulk API version 30 documentation gives the curl implementation by wrapping up all the contents in Zip containing a manifest file named request.txt. I got the solution using version 27.

I tried using multiple inputs in which 3rd one worked as desired. Now, I'm able to upload multiple attachments.

1. I provided the Zip file path as tmpInpuStream and got the same error by calling:

   connection.createBatchWithInputStreamAttachments(jobInfo, tmpInputStream, attachments);

   (Same Error)

2. Provided the path of menifest file as request.txt by calling:

   connection.createBatchWithInputStreamAttachments(jobInfo, tmpInputStream, attachments);

   (Same Error)

3. After analyzing the Apex Data Loader functionality, I provided the path of menifest file as request.csv and calling: (It worked)

   connection.createBatchWithInputStreamAttachments(jobInfo, tmpInputStream, attachments);

   bypassing createCSVFromBatches() method and the Name in Menifest file matching the Key of attachments Map.

   Also, the value of attachments Map containing the absolute path of File and Body of menifest file containing the relative path using #.
   Please find the code snippet attached here Binary File Attachments using Bulk API.