Java:处理不同国家的千分位和小数点

在国际化程序中，在不同国家中，千分位，小数点和分隔符是不相同的。这样在处理数字和货币的时候需要特别注意，在Java API中，可以把国家对应的Locale信息传给NumberFormat和DecimalFormatSymbols，然后进行相应的处理。

另外，在处理微软Excel的时候，不同国家的CSV分隔符也是不一样的，需要同样的方法进行处理。

下面是一个例子，可以看到不同国家的千分位和小数点，以及数字显示 

import java.io.IOException;
import java.text.DecimalFormat;
import java.text.DecimalFormatSymbols;
import java.text.NumberFormat;
import java.text.ParseException;
import java.util.ArrayList;
import java.util.List;
import java.util.Locale;

public class NumberFormatForLocaleTest {
    public static void main(String[] args) throws ParseException, IOException {
      System.out.println(System.getProperty("java.version"));
      List<Locale> allLocale = new ArrayList<Locale>();
      allLocale.add(new Locale("bs", "ID"));
      allLocale.add(new Locale("bs", "BS"));
      allLocale.add(new Locale("cs", "CZ"));
      allLocale.add(new Locale("da", "DK"));
      allLocale.add(new Locale("de", "DE"));
      allLocale.add(new Locale("en", "GB"));
      allLocale.add(new Locale("en", "US"));
      allLocale.add(new Locale("es", "ES"));
      allLocale.add(new Locale("fr", "FR"));
      allLocale.add(new Locale("fr", "CA"));
      allLocale.add(new Locale("hr", "HR"));
      allLocale.add(new Locale("it", "IT"));
      allLocale.add(new Locale("hu", "HU"));
      allLocale.add(new Locale("nl", "NL"));
      allLocale.add(new Locale("no", "NO"));
      allLocale.add(new Locale("nb", "NO"));
      allLocale.add(new Locale("pl", "PL"));
      allLocale.add(new Locale("pt", "PT"));
      allLocale.add(new Locale("pt", "BR"));
      allLocale.add(new Locale("ro", "RO"));
      allLocale.add(new Locale("de", "CH"));
      allLocale.add(new Locale("sk", "SK"));
      allLocale.add(new Locale("sl", "SI"));
      allLocale.add(new Locale("sr", "RS"));
      allLocale.add(new Locale("fi", "FI"));
      allLocale.add(new Locale("sv", "SE"));
      allLocale.add(new Locale("sv", "SW"));
      allLocale.add(new Locale("tl", "PH"));
      allLocale.add(new Locale("vi", "VN"));
      allLocale.add(new Locale("tr", "TR"));
      allLocale.add(new Locale("el", "GR"));
      allLocale.add(new Locale("en", "DEBUG"));
      allLocale.add(new Locale("ru", "RU"));
      allLocale.add(new Locale("bg", "BG"));
      allLocale.add(new Locale("uk", "UA"));
      allLocale.add(new Locale("iw", "IL"));
      allLocale.add(new Locale("hi", "IN"));
      allLocale.add(new Locale("th", "TH"));
      allLocale.add(new Locale("ko", "KR"));
      allLocale.add(new Locale("ja", "JP"));
      allLocale.add(new Locale("zh", "CN"));
      allLocale.add(new Locale("zh", "TW"));

//      Locale[] locales = Locale.getAvailableLocales();
//      allLocale = Arrays.asList(locales);

      System.out.println("| Locale| Thousand | Decimal| Example");
      for (Locale locale : allLocale) {
        if (locale.getCountry().length() == 0) {
          continue;
        }
        System.out.println(locale.getCountry());
        System.out.println(locale.getDisplayCountry());
        
        NumberFormat nf = NumberFormat.getInstance(locale);
        DecimalFormatSymbols dfs = ((DecimalFormat) nf).getDecimalFormatSymbols();

        String group = "single quote(')";
        if (dfs.getGroupingSeparator() == '\u00a0') {
          group = "space( )";
        } else if (dfs.getGroupingSeparator() == ',') {
          group = "comma(,)";
        } else if (dfs.getGroupingSeparator() == '.') {
          group = "dot(.)";
        }

        String decimal = "comma(,)";
        if (dfs.getDecimalSeparator() == '.') {
          decimal = "dot(.)";
        }

        System.out.println("| " + locale.toString() + " | " + group + " | "
            + decimal + " | " + nf.format(4000.04) + " |");
      }
    }
  }