spring mvc 时间日期转换（@DateTimeFormat 注解）

2019独角兽企业重金招聘Python工程师标准>>>

两种用法示例：

    @GetMapping("/date")
	public String datest(@DateTimeFormat(iso=ISO.DATE) Date date){
		System.out.println(date);
		return "lalalal";
	}

    @GetMapping("/date")
	public String datest(@DateTimeFormat(pattern = "yyyy/MM/dd") Date date){
		System.out.println(date);
		return "lalalal";
	}

使用 @DateTimeFormat 注解有两种做法，如上面代码所示。

示例说明：

第一种是按照ISO国际标准的日期时间格式解析参数中的日期时间的，具体格式为此枚举变量：

	/**
	 * Common ISO date time format patterns.
	 */
	enum ISO {

		/**
		 * The most common ISO Date Format {@code yyyy-MM-dd},
		 * e.g. "2000-10-31".
		 */
		DATE,

		/**
		 * The most common ISO Time Format {@code HH:mm:ss.SSSZ},
		 * e.g. "01:30:00.000-05:00".
		 */
		TIME,

		/**
		 * The most common ISO DateTime Format {@code yyyy-MM-dd'T'HH:mm:ss.SSSZ},
		 * e.g. "2000-10-31T01:30:00.000-05:00".
		 * 
This is the default if no annotation value is specified.
		 */
		DATE_TIME,

		/**
		 * Indicates that no ISO-based format pattern should be applied.
		 */
		NONE
	}

第二种是按照自定义的模式来解析时间，模式字符串的定义与遵循以下规则（摘自jdk 1.8 SimpleDateFormat）：

• The following pattern letters are defined (all other characters from 'A' to 'Z' and from 'a' to 'z' are reserved):

  Letter	Date or Time Component	Presentation	Examples
  G	Era designator	Text	AD
  y	Year	Year	1996; 96
  Y	Week year	Year	2009; 09
  M	Month in year (context sensitive)	Month	July; Jul; 07
  L	Month in year (standalone form)	Month	July; Jul; 07
  w	Week in year	Number	27
  W	Week in month	Number	2
  D	Day in year	Number	189
  d	Day in month	Number	10
  F	Day of week in month	Number	2
  E	Day name in week	Text	Tuesday; Tue
  u	Day number of week (1 = Monday, ..., 7 = Sunday)	Number	1
  a	Am/pm marker	Text	PM
  H	Hour in day (0-23)	Number	0
  k	Hour in day (1-24)	Number	24
  K	Hour in am/pm (0-11)	Number	0
  h	Hour in am/pm (1-12)	Number	12
  m	Minute in hour	Number	30
  s	Second in minute	Number	55
  S	Millisecond	Number	978
  z	Time zone	General time zone	Pacific Standard Time; PST; GMT-08:00
  Z	Time zone	RFC 822 time zone	-0800
  X	Time zone	ISO 8601 time zone	-08; -0800; -08:00

• The following examples show how date and time patterns are interpreted in the U.S. locale. The given date and time are 2001-07-04 12:08:56 local time in the U.S. Pacific Time time zone.

  Date and Time Pattern	Result
  "yyyy.MM.dd G 'at' HH:mm:ss z"	2001.07.04 AD at 12:08:56 PDT
  "EEE, MMM d, ''yy"	Wed, Jul 4, '01
  "h:mm a"	12:08 PM
  "hh 'o''clock' a, zzzz"	12 o'clock PM, Pacific Daylight Time
  "K:mm a, z"	0:08 PM, PDT
  "yyyyy.MMMMM.dd GGG hh:mm aaa"	02001.July.04 AD 12:08 PM
  "EEE, d MMM yyyy HH:mm:ss Z"	Wed, 4 Jul 2001 12:08:56 -0700
  "yyMMddHHmmssZ"	010704120856-0700
  "yyyy-MM-dd'T'HH:mm:ss.SSSZ"	2001-07-04T12:08:56.235-0700
  "yyyy-MM-dd'T'HH:mm:ss.SSSXXX"	2001-07-04T12:08:56.235-07:00
  "YYYY-'W'ww-u"	2001-W27-3

其他补充：

@ExceptionHandler 异常处理：

	@ExceptionHandler(Exception.class)
	public String handle(Exception exception){
		if (exception instanceof MethodArgumentTypeMismatchException) {
			return "传入参数格式不正确或参数解析异常！";
		}
		return exception.getMessage();
	}

如上所示，利用此注解@ExceptionHandler就可以实现对异常的处理。

若此示例代码段放在@Controller类中，就只可以处理它所在类被请求过程中发生的异常。如果需要处理多个@Controller类被请求过程中发生的异常，就需要将此代码段放在单独的一个类中，并且这个类需要加上@ControllerAdvice（或@RestControllerAdvice）注解。

转载于:https://my.oschina.net/silenceyawen/blog/917928