sqlgetNewId = conn.prepareStatement("SELECT schema.packageName.getMethod1 FROM DUAL");
sqlInsertRow = conn.prepareStatement("INSERT INTO schema.tableName VALUES (?, ?, (SELECT schema.packageName.getMethod2(?) FROM DUAL), ?)");
sqlGetEmptyClob = conn.prepareStatement("SELECT clobColumn FROM schema.tableName WHERE ID = ? FOR UPDATE");
 
public void updateTableWithClob(String docName,
InputStream is) throws Exception{
ResultSet rs = null;
  try{
    byte[] data = new byte[is.available()];	is.read(data);
    String docData = new String(data); 
	
    rs = sqlgetNewId.executeQuery();
    rs.next();
    int newRowId = rs.getInt( 1 );
    //insert the row
    sqlInsertRow.setInt( 1 , newRowId);
    sqlInsertRow.setString( 2 , docName);
    sqlInsertRow.setString( 3 , docName);
    //Empty lob with no connection to db but it is NOT null
    oracle.sql.CLOB emptyClob = oracle.sql.CLOB.empty_lob();
    sqlInsertRow.setClob( 4 , emptyClob);
    int result = sqlInsertRow.executeUpdate();
    
    //update the row
    sqlGetEmptyClob.setInt( 1 , newRowId);
    rs = sqlGetEmptyClob.executeQuery(); //get rs containing the clob to be updated
    rs.next();
    Clob clobFromTable = rs.getClob( 1 ); //get the clob from rs
    ( (oracle.sql.CLOB)clobFromTable ).putChars(  1  , docData.toCharArray() ); //update the clob
     rs.close();
    conn.commit();
    System.out.println("executed succesfully part2");
  }
  catch(Exception ex){
    ex.printStackTrace();
    conn.rollback();
  }
}