ResultSet rs;
Clob clob = rs.getClob(columnName);

 int  clobBufferSize = ((weblogic.jdbc.vendor.oracle.OracleThinClob)clob).getBufferSize();

StringBuffer strBuffer =  new  StringBuffer();
BufferedReader in =  new  BufferedReader( new  InputStreamReader(clob.getAsciiStream()));
 int  length = - 1 ;
 char [] buf =  new   char [clobBufferSize];
 while  ((length = in.read(buf,  0 , clobBufferSize)) != - 1 ) {
	strBuffer.append(buf);
	buf =  new   char [clobBufferSize];
}
in.close();
strBuffer.toString().trim().getBytes()