How to insert a clob in Java using getCharacterStream?

I have a JSP Page that allows the user to enter a description.
If the Description is > 4000 characters then the insert to database fails.  Thereofore, if its >4000 chars then I want to use this new function
writeStringToClob() that writes the CharcterStream.



I looked up Java site they have the following code-

  /**
  * Retrieve the character data from the input CLOB, save in a
  * StringBuffer and display the StringBuffer contents in GUI
  **/
  void writeCLOB(CLOB p_clob, String p_airPCode) {
    try {
      // Open a stream to read CLOB data
      Reader l_clobStream = p_clob.getCharacterStream();

      // Holds the CLOB data when the CLOB stream is being read
      StringBuffer l_suggestions = new StringBuffer();

      // Read from the CLOB stream and write to the stringbuffer
      int l_nchars = 0; // Number of chanracters read
      char[] l_buffer = new char[10];  //  Buffer holding characters being transferred
      while ((l_nchars = l_clobStream.read(l_buffer)) != -1) // Read from CLOB
        l_suggestions.append(l_buffer,0,l_nchars); // Write to StringBuffer

      l_clobStream.close();  // Close the CLOB input stream
      m_GUI.m_sugArea.append(new String(l_suggestions)); // Display in GUI
    } catch (Exception ex) { // Trap SQL and IO errors
      m_GUI.putStatus("Error in getting and drawing CLOB for the airport, "+p_airPCode+":");
      m_GUI.appendStatus(ex.toString());
    }
  }
---

I need to do the reverse of this...
I want to check if >4000 characters are entered then
a subroutine similar to above called
writeStringToClob (Clob p_clob, String p_descr)

This should first Select that Row and update it
like this -
Clob notes = rs.getClob("NOTES");
  PreparedStatement pstmt = con.prepareStatement(
          "UPDATE DESCR SET COMMENTS = ? WHERE DESCR > 4000");
pstmt.setClob(1, notes);
pstmt.executeUpdate();


Could someone please help me ?

Thanks.