[java]String和Date、Timestamp之间的转换

一、String与Date（java.util.Date）互转

 1.1 String -> Date

Date date = DateFormat.parse(String  str);

String dateStr = "2010/05/04 12:34:23";  
Date date = new Date();  
//注意format的格式要与日期String的格式相匹配  
DateFormat sdf = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss");  
try {  
     date = sdf.parse(dateStr);  
     System.out.println(date.toString());  
} catch (Exception e) {  
     e.printStackTrace();  
} 

  1.2 Date -> String

String str = DateFormat.format(Date date);

        String dateStr = "";  
        Date date = new Date();  
        //format的格式可以任意  
        DateFormat sdf = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss");  
        DateFormat sdf2 = new SimpleDateFormat("yyyy-MM-dd HH/mm/ss");  
        try {  
            dateStr = sdf.format(date);  
            System.out.println(dateStr);  
            dateStr = sdf2.format(date);  
            System.out.println(dateStr);  
        } catch (Exception e) {  
            e.printStackTrace();  
        }

二、String与Timestamp互转

   2.1 String ->Timestamp

Timestamp ts = Timestamp.valueOf(String str);

        Timestamp ts = new Timestamp(System.currentTimeMillis());  
        String tsStr = "2011-05-09 11:49:45";  
        try {  
            ts = Timestamp.valueOf(tsStr);  
            System.out.println(ts);  
        } catch (Exception e) {  
            e.printStackTrace();  
        } 

注：String的类型必须形如： yyyy-mm-dd hh:mm:ss[.f...] 这样的格式，中括号表示可选，否则报错

2.2 Timestamp -> String

方法1：String str = DateFormat.format(Timestamp ts);

方法2：String str = Timestamp.toString();

        Timestamp ts = new Timestamp(System.currentTimeMillis());  
        String tsStr = "";  
        DateFormat sdf = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss");  
        try {  
            //方法一  
            tsStr = sdf.format(ts);  
            System.out.println(tsStr);  
            //方法二  
            tsStr = ts.toString();  
            System.out.println(tsStr);  
        } catch (Exception e) {  
            e.printStackTrace();  
        }

三、Date（ java.util.Date ）和Timestamp互转

Date和Timestamp是父子类关系

  3.1 Timestamp（子类） -> Date（父类）

        Timestamp ts = new Timestamp(System.currentTimeMillis());  
        Date date = new Date();  
        try {  
            date = ts;  
            System.out.println(date);  
        } catch (Exception e) {  
            e.printStackTrace();  
        }  

3.2 Date -> Timestamp

父类不能直接向子类转化，可借助中间的String。

注：使用以下方式更简洁   

Timestamp ts = new Timestamp(date.getTime());

转自：https://www.cnblogs.com/mybloging/p/8067698.html