Problem exporting txt' file size is 23 KB and '.zip' size 4 MB

Question

I am using Apex 3.0 version screen to upload '.txt' file and '.zip' file containing images.
I can successfully export '.txt' file and '.zip' file containing images as long as '.txt' file size is < 23 KB and '.zip' file size < 4 MB from database table 'TBL_upload_file' to the OS directory on the server.
processing of Larger files (sizes 35 KB and 6 MB) produce following Error Message.
‘ORA-21560: argument 2 is null, invalid or out of range’ error.
Here is my code:
I am using following code to export Documents from database table 'TBL_upload_file' to the OS directory on the server.
create or replace procedure "PROC_LOAD_FILES_TO_FLDR_BYTES"
(pchr_text_file IN VARCHAR2,
pchr_zip_file IN VARCHAR2)
is
lzipfile varchar(100);
lzipname varchar(100);
sseq varchar(1000);
ldocname varchar(100);
lfile varchar(100);
-- loaddoc (p_file in number) as
l_file UTL_FILE.FILE_TYPE;
l_buffer RAW(32000);
l_amount NUMBER := 32000;
l_pos NUMBER := 1;
l_blob BLOB;
l_blob_len NUMBER;
l_file_name varchar(200);
l_doc_name varchar(200);
a_file_name varchar (200);
end_pos NUMBER;
begin
-- Get LOB locator
SELECT blob_content,doc_name
INTO l_blob,l_file_name
FROM tbl_upload_file
WHERE DOC_NAME = pchr_text_file;
--get length of blob
l_blob_len := DBMS_LOB.getlength(l_blob);
-- save blob length to determine end position
end_pos:= l_blob_len;
-- Open the destination file.
-- l_file := UTL_FILE.fopen('BLOBS','MyImage.gif','w', 32767);
l_file := UTL_FILE.fopen('BLOBS',l_file_name,'WB', 32760); --use write byte option supported in 10G
-- if small enough for a single write
IF l_blob_len < 32760 THEN
utl_file.put_raw(l_file,l_blob);
utl_file.fflush(l_file);
ELSE -- write in pieces
-- Read chunks of the BLOB and write them to the file
-- until complete.
WHILE l_pos < l_blob_len LOOP
DBMS_LOB.read(l_blob, l_amount, l_pos, l_buffer);
UTL_FILE.put_raw(l_file, l_buffer);
utl_file.fflush(l_file); --flush pending data and write to the file
-- set the start position for the next cut
l_pos := l_pos + l_amount;
-- set the end position if less than 32000 bytes, here end_pos captures length of the document
end_pos := end_pos - l_amount;
IF end_pos < 32000 THEN
l_amount := end_pos;
END IF;
END LOOP;
END IF;
--- zip file
-- Get LOB locator to locate zip file
SELECT blob_content,doc_name
INTO l_blob,l_doc_name
FROM tbl_upload_file
WHERE DOC_NAME = pchr_zip_file;
l_blob_len := DBMS_LOB.getlength(l_blob);
-- save blob length to determine end position
end_pos:= l_blob_len;
-- Open the destination file.
-- l_file := UTL_FILE.fopen('BLOBS','MyImage.gif','w', 32767);
l_file := UTL_FILE.fopen('BLOBS',l_doc_name,'WB', 32760); --use write byte option supported in 10G
-- if small enough for a single write
IF l_blob_len < 32760 THEN
utl_file.put_raw(l_file,l_blob);
utl_file.fflush(l_file); --flush out pending data to the file
ELSE -- write in pieces
-- Read chunks of the BLOB and write them to the file
-- until complete.
l_pos:=1;
WHILE l_pos < l_blob_len LOOP
DBMS_LOB.read(l_blob, l_amount, l_pos, l_buffer);
UTL_FILE.put_raw(l_file, l_buffer);
UTL_FILE.fflush(l_file); --flush pending data and write to the file
l_pos := l_pos + l_amount;
-- set the end position if less than 32000 bytes, here end_pos contains length of the document
end_pos := end_pos - l_amount;
IF end_pos < 32000 THEN
l_amount := end_pos;
END IF;
END LOOP;
END IF;
-- Close the file.
IF UTL_FILE.is_open(l_file) THEN
UTL_FILE.fclose(l_file);
END IF;
exception
WHEN NO_DATA_FOUND THEN
RAISE_APPLICATION_ERROR(-20214,'Screen fields cannot be blank, Proc_Load_Files_To_Fldr_BYTES.');      
WHEN TOO_MANY_ROWS THEN
RAISE_APPLICATION_ERROR(-20215,'More than one record exist in the tbl_load_file table, Proc_Load_Files_To_Fldr_BYTES.');     
WHEN OTHERS THEN
-- Close the file if something goes wrong.
IF UTL_FILE.is_open(l_file) THEN
UTL_FILE.fclose(l_file);
END IF;
RAISE_APPLICATION_ERROR(-20216,'Some other errors occurred, Proc_Load_Files_To_Fldr_BYTES.');     
end;
I am new to the Oracle.
Any help to modify this scipt and resolve this problem will be greatly appreciated.
Thank you.

Answer 1

Ask this question in the Apex forums. See Oracle Application Express (APEX)
Regards Nigel