java.util.Date、java.sql.Date、java.sql.Time、java.sql.Timestamp区别和联系

demo; import java.sql.Timestamp; import java.text.ParseException; import java.text.SimpleDateFormat; import java.util.Date; public class TestData { public static void main(String[] args) throws ParseException { Date d = new Date(new Date().getTime()); SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); String nowday1 = "2015-5-12 10:30:12"; String nowday2 = "2015-05-12 10:30:12"; Timestamp tt = new Timestamp(System.currentTimeMillis()); System.out.println(sdf.format(d));//Date -> String System.out.println(sdf.parse(nowday1)); // String -> Date System.out.println(sdf.format(tt)); // Timestamp -> String System.out.println(tt.valueOf(nowday2));//String -> Timestamp ：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 System.out.println(d=tt); // Timestamp -> Date 因为是父类直接向上转型 System.out.println(new Timestamp(d.getTime())); // Date ->Timestamp } } /* * oracle中Date与Timestamp转换 * SELECT TO_TIMESTAMP(TO_CHAR(SYSDATE, ‘YYYY-MM-DD HH24:MI:SS‘), ‘YYYY-MM-DD HH24:MI:SS‘) FROM dual; * SELECT TO_DATE(TO_CHAR(TO_TIMESTAMP(TO_CHAR(SYSDATE, ‘YYYY-MM-DD HH24:MI:SS‘), ‘YYYY-MM-DD HH24:MI:SS‘),‘YYYY-MM-DD HH24:MI:SS‘),‘YYYY-MM-DD HH24:MI:SS‘) FROM dual; * * */ /** 2015-05-12 10:44:15 Tue May 12 10:30:12 CST 2015 2015-05-12 10:44:15 2015-05-12 10:30:12.0 2015-05-12 10:44:15.108 2015-05-12 10:44:15.108 **/

java.util.Date、java.sql.Date、java.sql.Time、java.sql.Timestamp区别和联系

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