[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