Oracle xml_dom.writeToClob ignore the character set

Question

I'm trying to generate a xml file using oracle. After generating the xml using dbms_xmldom, it is stored in a CLOB and later written to a table.
The problem is that the character set ('UTF-8') is not included in the header even though it is specified using setCharset() procedure.
Following is the oracle script,
declare
export_file_ CLOB ;
str_export_file_ xmldom.DOMDocument;
main_node xmldom.DOMNode;
root_node xmldom.DOMNode;
root_elmt xmldom.DOMElement;
begin
str_export_file_ := xmldom.newDOMDocument;
xmldom.setVersion(str_export_file_, '1.0');
xmldom.setCharset(str_export_file_ , 'UTF-8');
main_node := xmldom.makeNode(str_export_file_);
root_elmt := xmldom.createElement(str_export_file_,'TextTranslation');
xmldom.setAttribute( root_elmt, 'version' ,'1.0');
xmldom.setAttribute( root_elmt, 'language' ,'ja');
xmldom.setAttribute( root_elmt, 'module' ,'DEMOAND');
xmldom.setAttribute( root_elmt, 'type' ,'VC');
root_node := xmldom.appendChild(main_node, xmldom.makeNode(root_elmt));
export_file_ :=' ';
xmldom.writeToClob( str_export_file_,export_file_,'UTF-8');
dbms_output.put_line ( export_file_ );
end;
The output is ,
<?xml version="1.0"?>
<TextTranslation version="1.0" language="ja" module="DEMOAND" type="VC"/>
If anybody can suggest me what I have done incorrectly that will be great.
Thanks in advance.

Answer 1

The character set you specify via setCharset() procedure is ignored unless you use writeToFile() later.
http://docs.oracle.com/cd/E11882_01/appdev.112/e25788/d_xmldom.htm#CHDCGDDB
Usage Notes
This is used for WRITETOFILE Procedures if not explicitly specified at that time.You can also use something like this :
SQL> set serveroutput on
SQL>
SQL> declare
  2 
  3   export_file  clob;
  4   prolog       clob := '<?xml version="1.0" encoding="UTF-8"?>';
  5 
  6  begin
  7 
  8    select prolog || chr(10) ||
  9           xmlserialize(document
10             xmlelement("TextTranslation"
11             , xmlattributes(
12                 '1.0' as "version"
13               , 'ja'  as "language"
14               , 'DEMOAND' as "module"
15               , 'VC' as "type"
16               )
17             )
18             indent
19           )
20    into export_file
21    from dual ;
22 
23    dbms_output.put_line ( export_file );
24 
25  end;
26  /
<?xml version="1.0" encoding="UTF-8"?>
<TextTranslation version="1.0" language="ja" module="DEMOAND" type="VC"/>
PL/SQL procedure successfully completed