Date、String、Calendar類型之間的轉化

1.Calendar 轉化 String 
 //獲取當前時間的具體狀況,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 轉化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 轉化String

SimpleDateFormat sdf= new SimpleDateFormat("yyyy-MM-dd");

String dateStr=sdf.format(new Date());

 

 

 

4.String 轉化Date 
String str="2010-5-27";

SimpleDateFormat sdf= new SimpleDateFormat("yyyy-MM-dd");

Date birthday = sdf.parse(str);

 

 

5.Date 轉化Calendar

Calendar calendar = Calendar.getInstance();
calendar.setTime(new java.util.Date());

 

6.Calendar轉化Date

Calendar calendar = Calendar.getInstance();
java.util.Date date =calendar.getTime();

 

下面有個例子，插入oralce表類型爲DATE的數據

 

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)";