Java 日期格式-包括附加字符

在 Java 中是否有与 php date ()样式格式等价的东西？我的意思是，在 php 中，我可以反斜杠-转义字符按字面意思对待它们。也就是说 是呀，是呀会变成 二零一零年。我在 Java 中没有发现任何类似的东西，所有示例都只处理内置的日期格式。

特别是，我处理 日历日期选择器和他们的 DateFormatString属性。

我之所以需要它，是因为在我的语言环境中，它需要以日期格式编写各种额外的东西，比如 d (代表天后的部分) ，m (代表年后的部分) ，年后的部分等等。在最坏的情况下，我可以使用字符串替换或 regexp，但也许有一个更简单的方法？先谢谢你！

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You can use String.format as documented in java.util.Formatter:

Calendar c = ...;
String s = String.format("%tY year", c);
// -> s == "2010 year" or whatever the year actually is
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java.text.SimpleDateFormat

SimpleDateFormat formatter = new SimpleDateFormat("yyyy/MM/dd");
String formattedDate = formatter.format(date);

You'll get more info here link text

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最佳答案

Sure, with the SimpleDateFormat you can include literal strings:

Within date and time pattern strings, unquoted letters from 'A' to 'Z' and from 'a' to 'z' are interpreted as pattern letters representing the components of a date or time string. Text can be quoted using single quotes (') to avoid interpretation. "''" represents a single quote. All other characters are not interpreted; they're simply copied into the output string during formatting or matched against the input string during parsing. 

 "hh 'o''clock' a, zzzz"    12 o'clock PM, Pacific Daylight Time
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Just for completeness, Java 8's DateTimeFormatter also supports this:

DateTimeFormatter.ofPattern("yyyy 'year'");
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java.time

Mark Jeronimus said it already. I am fleshing it out a bit more. Just put the text to be printed literally inside single quotes.

    DateTimeFormatter yearFormatter = DateTimeFormatter.ofPattern("yyyy 'year'");
System.out.println(LocalDate.of(2010, Month.FEBRUARY, 3).format(yearFormatter));
System.out.println(Year.of(2010).format(yearFormatter));
System.out.println(ZonedDateTime.now(ZoneId.of("Europe/Vilnius")).format(yearFormatter));

Output when running just now:

2010 year
2010 year
2019 year

If you are using a DateTimeFormatterBuilder and its appendPattern method, use single quotes in the same way. Or use its appendLiteral method instead and no single quotes.

How do we put a single quote in the format, then? Two single quotes produce one. It doesn’t matter if the double single quote is inside single quotes or not:

    DateTimeFormatter formatterWithSingleQuote = DateTimeFormatter.ofPattern("H mm'' ss\"");
System.out.println(LocalTime.now(ZoneId.of("Europe/London")).format(formatterWithSingleQuote));

10 28' 34"

    DateTimeFormatter formatterWithSingleQuoteInsideSingleQuotes
= DateTimeFormatter.ofPattern("hh 'o''clock' a, zzzz", Locale.ENGLISH);
System.out.println(ZonedDateTime.now(ZoneId.of("America/Los_Angeles"))
.format(formatterWithSingleQuoteInsideSingleQuotes));

02 o'clock AM, Pacific Daylight Time

All of the formatters above can be used for parsing too. For example:

    LocalTime time = LocalTime.parse("16 43' 56\"", formatterWithSingleQuote);
System.out.println(time);

16:43:56

The SimpleDateFormat class used when this question was asked nearly 10 years ago is notoriously troublesome and long outdated. I recommend that instead you use java.time, the modern Java date and time API. Which is why I demonstrate just that.

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