格式
| Symbol | Meaning | Presentation | Example |
|---|---|---|---|
| G | era designator | Text | AD |
| y | year | Number | 2009 |
| M | month in year | Text & Number | July & 07 |
| d | day in month | Number | 10 |
| h | hour in am/pm (1-12) | Number | 12 |
| H | hour in day (0-23) | Number | 0 |
| m | minute in hour | Number | 30 |
| s | second in minute | Number | 55 |
| S | millisecond | Number | 978 |
| E | day in week | Text | Tuesday |
| D | day in year | Number | 189 |
| F | day of week in month | Number | 2 (2nd Wed in July) |
| w | week in year | Number | 27 |
| W | week in month | Number | 2 |
| a | am/pm marker | Text | PM |
| k | hour in day (1-24) | Number | 24 |
| K | hour in am/pm (0-11) | Number | 0 |
| z | time zone | Text | Pacific Standard |
| ' | escape for text | Delimiter | (none) |
| ' | single quote | Literal | ' |
使用
上面的格式就是我们平时转换时间所用的显示样式，如把时间转换成指定样式：
public static final String DATE_LONG_STR = "yyyy-MM-dd HH:mm:ss";
public static String dateToString(Date date) {
if (null == date) {
return null;
}
DateTime dateTime = new DateTime(date.getTime());
return dateTime.toString(DATE_LONG_STR );
}