Decode base64 image into BLOB with PL/SQL - json

Question

I'm using the script below in order to fetch JSON file from MongoDB, parse it and then insert it into Oracle table.
The script works fine in a sense that it inserts all values correctly into Oracle table. That includes the value Photo which is an image of base64 formate and it is much larger than 32KB.
The column Photo in the table Appery_Photos is of the type CLOB while column DecodedPhoto is of the type BLOB.
The problem lies in the line blobOriginal := base64decode1(Photo); which I used to decode the CLOB into BLOB. The function base64decode1 has been replaced with several functions (i.e. decode_base64 , base64DecodeClobAsBlob_plsql, base64decode , from_base64 & finally JSON_EXT.DECODE).
The result was the same for all of them. That is, the resultant BLOB object cannot be openned as an image in any of images editors (I'm using Oracle SQL Developer to download it).
I checked CLOB, and I could not find any newlines \n, nor could I find any spaces (only + signs found). Furthermore, I inserted CLOB value into the base64-image-converter and it displays the image correctly. In addition, I tried to encode the resultant BLOB in base64 back in order to further validate (using the opposite functions provided in the links above), the resultant base64 is not the same at all.
BEGIN
l_http_request := UTL_HTTP.begin_request('https://api.appery.io/rest/1/db/collections/Photos?where=%7B%22Oracle_Flag%22%3A%22Y%22%7D' , 'GET' , 'HTTP/1.1');
-- ...set header's attributes
UTL_HTTP.set_header(l_http_request, 'X-Appery-Database-Id', '53f2dac5e4b02cca64021dbe');
l_http_response := UTL_HTTP.get_response(l_http_request);
BEGIN
LOOP
UTL_HTTP.read_text(l_http_response, buf);
l_response_text := l_response_text || buf;
END LOOP;
EXCEPTION
WHEN UTL_HTTP.end_of_body THEN
NULL;
END;
l_list := json_list(l_response_text);
FOR i IN 1..l_list.count
LOOP
A_id := json_ext.get_string(json(l_list.get(i)),'_id');
l_val := json_ext.get_json_value(json(l_list.get(i)),'Photo');
dbms_lob.createtemporary(Photo, true, 2);
json_value.get_string(l_val, Photo);
dbms_output.put_line(dbms_lob.getlength(Photo));
dbms_output.put_line(dbms_lob.substr(Photo, 20, 1));
blobOriginal := base64decode1(Photo);
A_Name := json_ext.get_string(json(l_list.get(i)),'Name');
Remarks := json_ext.get_string(json(l_list.get(i)),'Remarks');
Status := json_ext.get_string(json(l_list.get(i)),'Status');
UserId := json_ext.get_string(json(l_list.get(i)),'UserId');
A_Date := json_ext.get_string(json(l_list.get(i)),'Date');
A_Time := json_ext.get_string(json(l_list.get(i)),'Time');
MSG_status := json_ext.get_string(json(l_list.get(i)),'MSG_status');
Oracle_Flag := json_ext.get_string(json(l_list.get(i)),'Oracle_Flag');
acl := json_ext.get_string(json(l_list.get(i)),'acl');
INSERT
INTO Appery_Photos
(
A_id,
Photo,
DecodedPhoto,
A_Name,
Remarks,
Status,
UserId,
A_Date,
A_Time,
MSG_status ,
Oracle_Flag,
acl
)
VALUES
(
A_id,
Photo,
blobOriginal,
A_Name,
Remarks,
Status,
UserId,
A_Date,
A_Time,
MSG_status ,
Oracle_Flag,
acl
);
dbms_lob.freetemporary(Photo);
END LOOP;
-- finalizing
UTL_HTTP.end_response(l_http_response);
EXCEPTION
WHEN UTL_HTTP.end_of_body THEN
UTL_HTTP.end_response(l_http_response);
END;
Any help is deeply appreciated.

Answer 1

I found that is not in the function I used in the base64 decoding. Instead, the value I have is not base64 encoded strings, but base64 encode dataURi's, something like
data:image/jpeg;base64,/9j/4AAQSkZJRgABAQAAA
So I have to use something like: clobbase642blob( substr( Photo, instr( Photo, ',' ) + 1 ) )
The following script is inspired by Oracle Community answer
DECLARE
l_param_list VARCHAR2(512);
l_http_request UTL_HTTP.req;
l_http_response UTL_HTTP.resp;
l_response_text CLOB;
--l_response_text VARCHAR2(32767);
buf VARCHAR2(32767);
l_list json_list;
l_val json_value;
A_id VARCHAR2(100);
Photo CLOB;
A_Name VARCHAR2(100);
Remarks VARCHAR2(100);
Status VARCHAR2(100);
UserId VARCHAR2(100);
A_Date VARCHAR2(100);
A_Time VARCHAR2(100);
MSG_status VARCHAR2(100);
Oracle_Flag VARCHAR2(100);
acl VARCHAR2(100);
obj json_list;
blobOriginal BLOB := empty_blob();
clobInBase64 CLOB;
substring VARCHAR2(2000);
tmp BLOB;
n pls_integer := 0;
substring_length pls_integer := 2000;
------------------------------------------------------
FUNCTION clobbase642blob(
p_clob CLOB )
RETURN BLOB
IS
t_blob BLOB;
t_buffer VARCHAR2(32767);
t_pos NUMBER := 1;
t_size NUMBER := nls_charset_decl_len( 32764, nls_charset_id( 'char_cs' ) );
t_len NUMBER;
t_tmp raw(32767);
BEGIN
dbms_lob.createtemporary( t_blob, true );
t_len := LENGTH( p_clob );
LOOP
EXIT
WHEN t_pos > t_len;
t_buffer := REPLACE( REPLACE( SUBSTR( p_clob, t_pos, t_size ), chr(10) ), chr(13) );
t_pos := t_pos + t_size;
WHILE t_pos 0
LOOP
t_buffer := t_buffer || REPLACE( REPLACE( SUBSTR( p_clob, t_pos, 1 ), chr(10) ), chr(13) );
t_pos := t_pos + 1;
END LOOP;
t_tmp := utl_encode.base64_decode( utl_raw.cast_to_raw( t_buffer ) );
dbms_lob.writeappend( t_blob, utl_raw.length( t_tmp ), t_tmp );
END LOOP;
RETURN t_blob;
END;
------------------------------------------------------
BEGIN
-- service's input parameters
-- preparing Request...
l_http_request := UTL_HTTP.begin_request('https://api.appery.io/rest/1/db/collections/Photos?where=%7B%22Oracle_Flag%22%3A%22Y%22%7D' , 'GET' , 'HTTP/1.1');
-- ...set header's attributes
UTL_HTTP.set_header(l_http_request, 'X-Appery-Database-Id', '53f2dac5e4b02cca64021dbe');
l_http_response := UTL_HTTP.get_response(l_http_request);
BEGIN
LOOP
UTL_HTTP.read_text(l_http_response, buf);
l_response_text := l_response_text || buf;
END LOOP;
EXCEPTION
WHEN UTL_HTTP.end_of_body THEN
NULL;
END;
l_list := json_list(l_response_text);
FOR i IN 1..l_list.count
LOOP
A_id := json_ext.get_string(json(l_list.get(i)),'_id');
--deal with base64 URI photo >32KB
l_val := json_ext.get_json_value(json(l_list.get(i)),'Photo');
dbms_lob.createtemporary(Photo, true, 2);
json_value.get_string(l_val, Photo);
--dbms_output.put_line(dbms_lob.getlength(Photo));
--dbms_output.put_line(dbms_lob.substr(Photo, 20, 1));
blobOriginal := clobbase642blob( SUBSTR( Photo, 24 ) );
A_Name := json_ext.get_string(json(l_list.get(i)),'Name');
Remarks := json_ext.get_string(json(l_list.get(i)),'Remarks');
Status := json_ext.get_string(json(l_list.get(i)),'Status');
UserId := json_ext.get_string(json(l_list.get(i)),'UserId');
A_Date := json_ext.get_string(json(l_list.get(i)),'Date');
A_Time := json_ext.get_string(json(l_list.get(i)),'Time');
MSG_status := json_ext.get_string(json(l_list.get(i)),'MSG_status');
Oracle_Flag := json_ext.get_string(json(l_list.get(i)),'Oracle_Flag');
acl := json_ext.get_string(json(l_list.get(i)),'acl');
INSERT
INTO Appery_Photos
(
A_id,
Photo,
DecodedPhoto,
A_Name,
Remarks,
Status,
UserId,
A_Date,
A_Time,
MSG_status ,
Oracle_Flag,
acl
)
VALUES
(
A_id,
Photo,
blobOriginal,
A_Name,
Remarks,
Status,
UserId,
A_Date,
A_Time,
MSG_status ,
Oracle_Flag,
acl
);
dbms_lob.freetemporary(Photo);
END LOOP;
-- finalizing
UTL_HTTP.end_response(l_http_response);
EXCEPTION
WHEN UTL_HTTP.end_of_body THEN
UTL_HTTP.end_response(l_http_response);
END;
/

Answer 2

It is Base64 or HexBinary...
This works for HexBinary
function DESERIALIZE_HEX_BLOB(P_SERIALIZATION CLOB)
return BLOB
is
V_BLOB BLOB;
V_OFFSET INTEGER := 1;
V_AMOUNT INTEGER := 32000;
V_INPUT_LENGTH NUMBER := DBMS_LOB.GETLENGTH(P_SERIALIZATION);
V_HEXBINARY_DATA VARCHAR2(32000);
begin
if (P_SERIALIZATION is NULL) then return NULL; end if;
DBMS_LOB.CREATETEMPORARY(V_BLOB,TRUE,DBMS_LOB.CALL);
while (V_OFFSET <= V_INPUT_LENGTH) loop
V_AMOUNT := 32000;
DBMS_LOB.READ(P_SERIALIZATION,V_AMOUNT,V_OFFSET,V_HEXBINARY_DATA);
V_OFFSET := V_OFFSET + V_AMOUNT;
DBMS_LOB.APPEND(V_BLOB,TO_BLOB(HEXTORAW(V_HEXBINARY_DATA)));
end loop;
return V_BLOB;
end;
--
And could probably be modified to handle Base64 without too much trouble.