用减号格式化负数美元，而不是括号 (Java)
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Format negative amount of USD with a minus sign, not brackets (Java)
提问by ?ygimantas
How do I get NumberFormat.getCurrencyInstance()to print negative USD currency values with a minus sign?
如何NumberFormat.getCurrencyInstance()使用减号打印负美元货币价值？
采纳答案by ?ygimantas
Since I faced this problem again, I did some research and found a more resilient solution provided by an ICU:
由于我再次遇到这个问题，我做了一些研究，发现了一个ICU提供的更具弹性的解决方案：
NumberFormatter
.withLocale(...)
.unit(Currency.getInstance("USD"))
.sign(SignDisplay.AUTO) // "123", "0", and "-123"
.format(123)
.toString();
Check API documentation of NumberFormatterfor more details.
查看NumberFormatter 的API 文档以获取更多详细信息。
回答by Michael Borgwardt
It's probably best to create your own DecimalFormatif you want a specific format rather than relying on the default.
DecimalFormat如果您想要特定格式而不是依赖默认格式，最好创建自己的格式。
Edit:You could probably also cast the result of NumberFormat.getCurrencyInstance() to DecimalFormatand adjust it to your preferences.
编辑：您也可以将 NumberFormat.getCurrencyInstance() 的结果转换为DecimalFormat并根据您的偏好进行调整。
回答by Gennadiy
Here is one I always end up using either in a java class or via the fmt:formatNumber jstl tag:
这是我最终在 java 类中或通过 fmt:formatNumber jstl 标签使用的一个：
DecimalFormat format = new DecimalFormat("$#,##0.00;$-#,##0.00");
String formatted = format.format(15.5);
It always produces at least a $0.00 and is consistent when displayed. Also includes thousands seperators where needed. You can move the minus sign in front of the dollar sign if that is your requirement.
它总是至少产生 $0.00 并且在显示时是一致的。在需要时还包括数千个分隔符。如果这是您的要求，您可以在美元符号前面移动减号。
回答by ageektrapped
It requires a little tweaking of the DecimalFormat returned by NumberFormat.getCurrencyInstance()to do it in a locale-independent manner. Here's what I did (tested on Android):
它需要对返回的 DecimalFormat 进行一些调整，NumberFormat.getCurrencyInstance()以独立于语言环境的方式执行此操作。这是我所做的（在Android上测试）：
DecimalFormat formatter = (DecimalFormat)NumberFormat.getCurrencyInstance();
String symbol = formatter.getCurrency().getSymbol();
formatter.setNegativePrefix(symbol+"-"); // or "-"+symbol if that's what you need
formatter.setNegativeSuffix("");
IIRC, Currency.getSymbol()may not return a value for all locales for all systems, but it should work for the major ones (and I think it has a reasonable fallback on its own, so you shouldn't have to do anything)
IIRC，Currency.getSymbol()可能不会为所有系统的所有语言环境返回一个值，但它应该适用于主要的语言环境（我认为它本身有一个合理的后备，所以你不应该做任何事情）
回答by E-dou
Try:
尝试：
NumberFormat.getCurrencyInstance(Locale.CANADA);
NumberFormat.getCurrencyInstance(Locale.CANADA);
回答by Pnemonic
NumberFormat.getCurrencyInstance(Locale.UK);
回答by rheaghen
Why poi REFUSES to support the FIRST option in excel currency formatting is beyond me! 
为什么 poi 拒绝支持 excel 货币格式中的 FIRST 选项是我无法理解的！
I don't like using the DecimalFormat for currency because your end cell value becomes a non-numeric with the introduction of the currency symbol. While working for a major financial institution, I was tasked with resolving this formatting issue. The core idea of this change is, because POI refuses to be reasonable and have comprehensive support of Excel's native options, I will infiltrate their code and change their values at the core. The following is my WORKAROUND:
我不喜欢使用 DecimalFormat 作为货币，因为随着货币符号的引入，您的最终单元格值变为非数字。在为一家大型金融机构工作时，我的任务是解决这个格式问题。这个改动的核心思想是，因为POI拒绝合理并且对Excel的原生选项有全面的支持，所以我会渗透到他们的代码中，在核心改变他们的值。以下是我的解决方法：
private static final String CURRENCY_FORMAT_OVERRIDE = "\"$\"#,##0.00_);-\"$\"#,##0.00";
private static final String CURRENCY_FORMAT_TARGET = "\"$\"#,##0.00_);(\"$\"#,##0.00)";
static { // static class level initializer
Field field = org.apache.poi.ss.usermodel.BuiltinFormats.class.getDeclaredField("_formats");
field.setAccessible(true);
String[] _formats = (String[])field.get(new org.apache.poi.ss.usermodel.BuiltinFormats());
for(int i = 0; i < _formats.length; ++i) {
if(_formats[i].equals(CURRENCY_FORMAT_TARGET)) {
_formats[i]=CURRENCY_FORMAT_OVERRIDE;
System.out.println("TAKE THAT, POI!!!");
}
}
}
