ByteArrayOutputStream baos = new ByteArrayOutputStream();
XMLEncoder encoder = new XMLEncoder(baos);
encoder.setPersistenceDelegate(java.sql.Date.class, new DatePersistenceDelegate());
encoder.setPersistenceDelegate(Timestamp.class, new TimestampPersistenceDelegate());
try {
encoder.writeObject(expr);
} finally {
encoder.close();
}
try {
return baos.toString("UTF-8");