日期时间解析类
日期时间解析类
该类位于Android.text.format.DateFormat这个package中，该类提供了Java中的三种时间对象，提示大家下面三种方法为静态可以直接调用，如下:
1. final static CharSequence format(CharSequence inFormat, Date inDate) //传入Date对象
Given a format string and a Date object, returns a CharSequence containing the requested date.
2. final static CharSequence format(CharSequence inFormat, Calendar inDate) //Calendar对象
Given a format string and a Calendar object, returns a CharSequence containing the requested date.
3. final static CharSequence format(CharSequence inFormat, long inTimeInMillis) //long对象
Given a format string and a time in milliseconds since Jan 1, 1970 GMT, returns a CharSequence containing the requested date. 第一个参数均为inFormat这是一个CharSequence接口的String类型，它提供了灵活的时间格式解析字符串描述，（注意大小写要区分）
下面就生日为例子如下
"MM/dd/yy h:mmaa" -> "11/03/99 20:06am"
"MMM dd, yyyy h:mmaa" -> "Nov 3, 1999 20:06am"
"MMMM dd, yyyy h:mmaa" -> "November 3, 1999 20:06am"
"E, MMMM dd, yyyy h:mmaa" -> "Tues , November 3, 1999 20:06am"
"EEEE, MMMM dd, yyyy h:mmaa" -> "Tues day, Nov 3, 1999 20:06am"
用24小时制：
"EEEE, MMMM dd, yyyy kk:mm" -> "Tues day, Nov 3, 1987 23:23"
其中：12小时制 ：hh; 24小时制: kk
SimpleDateFormat ，则为： hh; HH
其中判断当前系统时间是否为24小时制式:
android.text.format.DateFormat类的static boolean is24HourFormat(Context context)
Demo： 获取是否是24小时，如果是24小时，显示举例为13:09；若是12进制，则显示举例为2:01pm：
boolean is24HourFormat = DateFormat.is24HourFormat(context);
String format =is24HourFormat ?"kk:mm":"hh:mmaa";
String result = DateFormat.format(format,System.currentTimeMillis()).toString();Constants：
public static final char AM_PM
Since: API Level 3
This designator indicates whether the HOUR field is before or after noon. The output is lower-case. Examples: a -> a or p aa -> am or pm
Constant Value: 97 (0x00000061)
public static final char CAPITAL_AM_PM
Since: API Level 3
This designator indicates whether the HOUR field is before or after noon. The output is capitalized. Examples: A -> A or P AA -> AM or PM
Constant Value: 65 (0x00000041)
public static final char DATE
Since: API Level 3
This designator indicates the day of the month. Examples for the 9th of the month: d -> 9 dd -> 09
Constant Value: 100 (0x00000064)
public static final char DAY
Since: API Level 3
This designator indicates the name of the day of the week. Examples for Sunday: E -> Sun EEEE -> Sunday
Constant Value: 69 (0x00000045)
public static final char HOUR
Since: API Level 3
This designator indicates the hour of the day in 12 hour format. Examples for 3pm: h -> 3 hh -> 03
Constant Value: 104 (0x00000068)
public static final char HOUR_OF_DAY
Since: API Level 3
This designator indicates the hour of the day in 24 hour format. Example for 3pm: k -> 15 Examples for midnight: k -> 0 kk -> 00
Constant Value: 107 (0x0000006b)
public static final char MINUTE
Since: API Level 3
This designator indicates the minute of the hour. Examples for 7 minutes past the hour: m -> 7 mm -> 07
Constant Value: 109 (0x0000006d)
public static final char MONTH
Since: API Level 3
This designator indicates the month of the year Examples for September: M -> 9 MM -> 09 MMM -> Sep MMMM -> September
Constant Value: 77 (0x0000004d)
public static final char QUOTE
Since: API Level 3
Text in the format string that should be copied verbatim rather that interpreted as formatting codes must be surrounded by the QUOTE character. If you need to embed a literal QUOTE character in the output text then use two in a row.
Constant Value: 39 (0x00000027)
public static final char SECONDS
Since: API Level 3
This designator indicates the seconds of the minute. Examples for 7 seconds past the minute: s -> 7 ss -> 07
Constant Value: 115 (0x00000073)
public static final char TIME_ZONE
Since: API Level 3
This designator indicates the offset of the timezone from GMT. Example for US/Pacific timezone: z -> -0800 zz -> PST
Constant Value: 122 (0x0000007a)
public static final char YEAR
Since: API Level 3
This designator indicates the year. Examples for 2006 y -> 06 yyyy -> 2006