The code snippet below shows how to use of java.sql.Date with PreparedStatement.

Java Code:
java.util.Date today = new java.util.Date();
java.sql.Date sqlToday = new java.sql.Date(today.getTime());

PreparedStatement p = theConn.prepareStatement
    ("select * from cust where purchase_date < ?");
p.setDate(1, sqlToday);
ResultSet rs = p.executeQuery();