Inserting large xml data into xmltype

Question

Hi all,
In my project I need to insert very large XML data into xmltype column.
My table:
CREATE TABLE TransDetailstblCLOB ( id number, data_xml XMLType) XmlType data_xml STORE AS CLOB;
I am using JDBC approach to insert values. It works fine for data less than 4000 bytes when using preparedStatement.setString(1, xmlData). As I have to insert large Xml data >4000 bytes I am now using preparedStatement.setClob() methods.
My code works fine for table which has column declared as CLOB expicitly. But for TransDetailstblCLOB where the column is declared as XMLTYPE and storage option as CLOB I am getting the error : "ORA-01461: can bind a LONG value only for insert into a LONG column".
This error means that there is a mismatch between my setClob() and column. which means am I not storing in CLOB column.
I read in Oracle site that
When you create an XMLType column without any XML schema specification, a hidden CLOB column is automatically created to store the XML data. The XMLType column itself becomes a virtual column over this hidden CLOB column. It is not possible to directly access the CLOB column; however, you can set the storage characteristics for the column using the XMLType storage clause."
I dont understand its stated here that it is a hidden CLOB column then why not I use setClob()? It worked fine for pure CLOB column (another table) then Why is it giving such error for XMLTYPE table?
I am struck up with this since 3 days. Can anyone help me please?
My code snippet:
query = "INSERT INTO po_xml_tab VALUES (?,XMLType(?)) ";
          //query = "INSERT INTO test VALUES (?,?) ";
     // Get the statement Object
     pstmt =(OraclePreparedStatement) conn.prepareStatement(query);
     // pstmt = conn.prepareStatement(query);
     //xmlData="test";
//      If the temporary CLOB has not yet been created, create new
     temporaryClob = oracle.sql.CLOB.createTemporary(conn, true, CLOB.DURATION_SESSION);
     // Open the temporary CLOB in readwrite mode to enable writing
     temporaryClob.open(CLOB.MODE_READWRITE);
     log.debug("tempClob opened"+"size bef writing data"+"length "+temporaryClob.getLength()+
               "buffer size "+temporaryClob.getBufferSize()+"chunk size "+temporaryClob.getChunkSize());
     OutputStream out = temporaryClob.getAsciiOutputStream();
     InputStream in = new StringBufferInputStream(xmlData);
int length = -1;
int wrote = 0;
int chunkSize = temporaryClob.getChunkSize();
chunkSize=xmlData.length();
byte[] buf = new byte[chunkSize];
while ((length = in.read(buf)) != -1) {
out.write(buf, 0, length);
wrote += length;
temporaryClob.setBytes(buf);
log.debug("Wrote lenght"+wrote);
     // Bind this CLOB with the prepared Statement
     pstmt.setInt(1,100);
     pstmt.setStringForClob(2, xmlData);
     int i =pstmt.executeUpdate();
     if (i == 1) {
     log.debug("Record Successfully inserted!");
     }

Answer 1

try this, in adodb works:
declare poXML CLOB;
BEGIN
poXML := '<OIDS><OID>large text</OID></OIDS>';
UPDATE a_po_xml_tab set podoc=XMLType(poXML) WHERE poid = 102;
END;