BASE64 (PDF) CLOB to BLOB

Question

Hello everybody! I have to convert a BASE64 representation of a PDF file to BLOB. I found one example on the Internet but there is something wrong with it and I can't figure it out.
create or replace function decode_base64(p_clob_in in clob) return blob is
v_blob           blob;
v_offset         integer;
v_buffer_varchar varchar2(32000);
v_buffer_raw     raw(32000);
v_buffer_size    binary_integer := 32000;
begin
if p_clob_in is null then
return null;
end if;
dbms_lob.CREATETEMPORARY(v_blob, true);
v_offset := 1;
FOR i IN 1..CEIL(dbms_lob.GETLENGTH(p_clob_in) / v_buffer_size)
loop
dbms_lob.READ(p_clob_in, v_buffer_size, v_offset, v_buffer_varchar);
v_buffer_raw := utl_encode.BASE64_DECODE(utl_raw.CAST_TO_RAW(v_buffer_varchar));*
dbms_lob.WRITEAPPEND(v_blob, utl_raw.LENGTH(v_buffer_raw), v_buffer_raw);
v_offset := v_offset v_buffer_size;+
end loop;
return v_blob;
end decode_base64;
The above procedure should work with files of any size (since there is a loop), but it only works when the PDF is smaller than 32 KB.

Answer 1

Just a guess.
You may have additional CRLFs added when encoding.
Try this:
create or replace function replaceClob (opCLob CLOB,cpReplaceStr VARCHAR2,cpReplaceWith VARCHAR2) RETURN CLOB IS
   cBuffer    VARCHAR2 (32767);
   nBuffer    BINARY_INTEGER := 32767;
   nStart     PLS_INTEGER := 1;
   nLen            PLS_INTEGER;
   oCRtn      CLOB := EMPTY_CLOB;
   BEGIN
     DBMS_LOB.CreateTemporary(oCRtn,TRUE);
     nLen := DBMS_LOB.GetLength(opCLob);
     WHILE nStart < nLen
     LOOP
       DBMS_LOB.Read(opCLob, nBuffer, nStart, cBuffer);
       IF cBuffer IS NOT NULL THEN
         cBuffer := REPLACE(cBuffer, cpReplaceStr, cpReplaceWith);
         DBMS_LOB.WriteAppend(oCRtn, LENGTH(cBuffer), cBuffer);
       END IF;
       nStart := nStart + nBuffer;
     END LOOP;
     RETURN oCRtn;
   END;and then add to your code:
create or replace function decode_base64(p_clob_in in clob) return blob is
       v_blob blob;
       v_offset integer;
       v_tem_clob clob;
       v_buffer_varchar varchar2(32000);
       v_buffer_raw raw(32000);
       v_buffer_size binary_integer := 32000;
       --v_buffer_size binary_integer := 3*1024;      
       begin
       if p_clob_in is null then
          return null;
       end if;
       -- Add this line
       v_tem_clob := replaceClob(p_clob_in,UTL_TCP.CRLF,'');
       dbms_lob.CREATETEMPORARY(v_blob, true);
       v_offset := 1;
       FOR i IN 1..CEIL(dbms_lob.GETLENGTH(v_tem_clob) / v_buffer_size) loop
           dbms_lob.READ(v_tem_clob, v_buffer_size, v_offset, v_buffer_varchar);          
           v_buffer_raw := utl_encode.BASE64_DECODE(utl_raw.CAST_TO_RAW(v_buffer_varchar));
           dbms_lob.WRITEAPPEND(v_blob, utl_raw.LENGTH(v_buffer_raw), v_buffer_raw);
           v_offset := v_offset + v_buffer_size;
       end loop;
       return v_blob;
end decode_base64;Not tested.
HTH
Thomas