Date、String、Calendar类型之间的转化

1.Calendar 转化 String
 //获取当前时间的具体情况,如年,月,日,week,date,分,秒等
        Calendar calendat = Calendar.getInstance(); SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
String dateStr = sdf.format(calendar.getTime());  
2.String 转化Calendar String str="2010-5-27";
SimpleDateFormat sdf= new SimpleDateFormat("yyyy-MM-dd"); Date date =sdf.parse(str); Calendar calendar = Calendar.getInstance(); calendar.setTime(date);     3.Date 转化String SimpleDateFormat sdf= new SimpleDateFormat("yyyy-MM-dd"); String dateStr=sdf.format(new Date());       4.String 转化Date
String str="2010-5-27"; SimpleDateFormat sdf= new SimpleDateFormat("yyyy-MM-dd"); Date birthday = sdf.parse(str);     5.Date 转化Calendar Calendar calendar = Calendar.getInstance();
calendar.setTime(new java.util.Date());   6.Calendar转化Date Calendar calendar = Calendar.getInstance();
java.util.Date date =calendar.getTime();   下面有个例子，插入oralce表类型为DATE的数据   SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMdd HHmmss");
    String date = sdf.format(new Date());      -----------------------------------------      String sql = "Insert into SM_SEND (*****************) " +
                  "values (*******************************                    "',1," + "to_date('" +date+ "','YYYY-MM-DD HH24:MI:SS')" +
                   "," + "to_date('" +date+ "','YYYY-MM-DD HH24:MI:SS')" +
                   ",0,null,null,null,null,null,null,null)";