2SE_专题_日期处理/日期处理_4

鱼欲遇雨：每日都学习一点，持之以恒，天道酬勤！不能用电脑时，提前补上！（2012.9.16）

Agenda(议程，日常工作事项）
1 What is UTC/UT?
2 What is GMT?
3 How to get the current time?
4 How to format it?
5 How to convert a string to a date/time?
6 How to process the date / time with database?

Here's the answer:
1 java.lang.System
2 java.util.Date
3 java.util.Calendar
4 java.util.GregorianCalendar
5 java.util.TimeZone
6 java.text.DateFormat
7 java.text.SimpleDateFormat
8 java.sql.Date
9 java.sql.Time
10 java.sql.Timestamp

// TestDateTime.javaimport java.sql.Timestamp;import java.util.Calendar;import java.util.Date;import java.util.GregorianCalendar;import java.util.TimeZone;public class TestDateTime {/** * @param args */public static void main(String[] args) {//System.out.println(System.currentTimeMillis());System.currentTimeMillis();Date d = new Date();Calendar c = Calendar.getInstance();String s = "1970-09-14 08:24:37";Timestamp ts = Timestamp.valueOf(s);System.out.println(ts);Calendar cJapan = new GregorianCalendar(TimeZone.getTimeZone("Japan"));System.out.println(cJapan.get(Calendar.HOUR_OF_DAY));for(String str : TimeZone.getAvailableIDs()) {System.out.println(str);}}}