First of all, a blob in Oracle points to somthing internal, so an insert statement looks like this:

);
INSERT INTO myTable (someBlobField) values( empty_blob() )

After that, you can get the record, and get the BinaryInputstream and start the binary stream to the server.... Example is here: http://asktom.oracle.com/pls/ask/f?p=4950:8:::::F4950_P8_DISPLAYID:238014476571



Getting the jpg from the server is a question of creating a servlet that handles the requests for images:

All the servlet needs to do is to get the blob, and stream it to the OutputStream of the servlet, mime-type "image/jpeg"