java程序向oracle数据库中插入当前时间格式大集

public class Test{
public
static void main (String args []){ 
java.util.Date
a = new java.util.Date();
System.out.println(a);
java.sql.Date
b = new java.sql.Date(a.getTime());
System.out.println(b);
java.sql.Time
c = new java.sql.Time(a.getTime());
System.out.println(c);
java.sql.Timestamp
d=new java.sql.Timestamp(a.getTime());