As far as I understand it, the method HarmonySerialBlob.getBinaryStream(long, long) takes two arguments <pos> and <length> and is supposed to produce a ByteArrayInputStream() with a substring of the Blob's Contents that starts at <pos> and has length <length>.
Unfortunately, the error handling in this method makes it impossible to retrieve a suffix of the Blobs contents as the last character is always missing.
When calling this method with <pos>=0, then it raises the SQLException XJ087. Hence, <pos> must always be > 0.
When calling this method with <pos>=1 and <length>=blob.length(), then it also raises the SQLException, because pos+length > blob.length(). Hence, <length> can at most be set to blob.length()-1.
When calling this method with <pos>=1 and <length>=blob.length()-1, then it gives a ByteArrayInputStream which is missing the last character from the blob.
The fact that the last character is missing makes sense, when <length> is set to blob.length()-1.
But it does not make sense to prohibit setting <length>=blob.length() when this is the only way to include the last character in the ByteArrayInputStream.