android 使用String.format("%.2f",67.876)自已定义语言(俄语、西班牙语)会把小数点变为逗号

时间:2023-11-25 23:59:26

市场人员反映公司的app使用系统设置俄语、西班牙语,double数据会把小数点变为逗号。调试一下,是自定义的语言时候(例如,俄语、西班牙语)转换String.format("%.2f",67.876)。会出现的。

1、android 系统,设置系统语言的步骤

Android【设置】-【语言和输入法】-【语言】列表中找到相应语言所对应的列表项

2、问题分析

java.util.Locale类

在这个Locale类里面,有些语言是没有,例如俄语、西班牙语等。那么这时候android开发时候需要这些语言,怎么办。只好后面自已新建,自定义。

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/**
 * Locale constant for en_CA.
 */
public static final Locale CANADA = new Locale(true, "en", "CA");
/**
 * Locale constant for fr_CA.
 */
public static final Locale CANADA_FRENCH = new Locale(true, "fr", "CA");
/**
 * Locale constant for zh_CN.
 */
public static final Locale CHINA = new Locale(true, "zh", "CN");
/**
 * Locale constant for zh.
 */
public static final Locale CHINESE = new Locale(true, "zh", "");
/**
 * Locale constant for en.
 */
public static final Locale ENGLISH = new Locale(true, "en", "");

Locale类里面,私有方法新建语言的。可是不提供外部调用。

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/**
     * There's a circular dependency between toLowerCase/toUpperCase and
     * Locale.US. Work around this by avoiding these methods when constructing
     * the built-in locales.
     *
     * @param unused required for this constructor to have a unique signature
     */
    private Locale(boolean unused, String lowerCaseLanguageCode, String upperCaseCountryCode) {
        this.languageCode = lowerCaseLanguageCode;
        this.countryCode = upperCaseCountryCode;
        this.variantCode = "";
    }

源码中的这个方法是共外部新建语言的。
构造一个新的{ @code地区}使用指定的语言,国家,和变体编码。

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/**
 * Constructs a new {@code Locale} using the specified language, country,
 * and variant codes.
 */
public Locale(String language, String country, String variant) {
    if (language == null || country == null || variant == null) {
        throw new NullPointerException();
    }
    if (language.isEmpty() && country.isEmpty()) {
        languageCode = "";
        countryCode = "";
        variantCode = variant;
        return;
    }
    languageCode = language.toLowerCase(Locale.US);
    // Map new language codes to the obsolete language
    // codes so the correct resource bundles will be used.
    if (languageCode.equals("he")) {
        languageCode = "iw";
    } else if (languageCode.equals("id")) {
        languageCode = "in";
    } else if (languageCode.equals("yi")) {
        languageCode = "ji";
    }
    countryCode = country.toUpperCase(Locale.US);
    // Work around for be compatible with RI
    variantCode = variant;
}
@Override public Object clone() {
    try {
        return super.clone();
    } catch (CloneNotSupportedException e) {
        throw new AssertionError(e);
    }
}

这是我在外面新建俄语、西班牙语。因为调用不了上面是有方法。只有这个方法。
这个方法的新建是为了匹配资源文件的翻译的以及后面的系统的调用

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private static final Locale Locale_Russia = new Locale("RUS", "ru", "");
    private static final Locale Locale_Spanish = new Locale("ES", "es", "");
    public static void setApplicationLauguageType(Context context, int type) {
        if (context == null) return;
        Resources resources = context.getResources();//获得res资源对象
        Configuration config = resources.getConfiguration();//获得设置对象
        DisplayMetrics dm = resources .getDisplayMetrics();//获得屏幕参数:主要是分辨率,像素等。
         
        switch (type) {
        case 0:
            config.locale = Locale.getDefault();
            break;
        case 1:
            config.locale = Locale.SIMPLIFIED_CHINESE;
            break;
        case 2:
            config.locale = Locale.ENGLISH;
            break;
        case 3:
            config.locale = Locale_Russia;
            break;
        case 4:
            config.locale = Locale_Spanish;
            break;
        default:
            config.locale = Locale.getDefault();
            break;
        }
         
        resources.updateConfiguration(config, dm);
    }
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/**
     * Returns a localized formatted string, using the supplied format and arguments,
     * using the user's default locale.
     *
     *

If you're formatting a string other than for human * consumption, you should use the {@code format(Locale, String, Object...)} * overload and supply {@code Locale.US}. See * "Be wary of the default locale". * * @param format the format string (see {@link java.util.Formatter#format}) * @param args * the list of arguments passed to the formatter. If there are * more arguments than required by {@code format}, * additional arguments are ignored. * @return the formatted string. * @throws NullPointerException if {@code format == null} * @throws java.util.IllegalFormatException * if the format is invalid. * @since 1.5 */ public static String format(String format, Object... args) { return format(Locale.getDefault(), format, args); }

这上面是一般调用方法,String strResult = String.format("%0.2f",543.6356);
这句语句是double型543.6356保留小数点的两位,并转化成String类型。
调用这个方法时候,其实是默认调用format(Locale.getDefault(), format, args)。因为返回是调用了这个。多了一个参数就是Locale.getDefault()。这个参数使获取系统设置的语言。并作为后面的转换参数的。

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/**
  * Returns a formatted string, using the supplied format and arguments,
  * localized to the given locale.
  *
  * @param locale
  *            the locale to apply; {@code null} value means no localization.
  * @param format the format string (see {@link java.util.Formatter#format})
  * @param args
  *            the list of arguments passed to the formatter. If there are
  *            more arguments than required by {@code format},
  *            additional arguments are ignored.
  * @return the formatted string.
  * @throws NullPointerException if {@code format == null}
  * @throws java.util.IllegalFormatException
  *             if the format is invalid.
  * @since 1.5
  */
 public static String format(Locale locale, String format, Object... args) {
     if (format == null) {
         throw new NullPointerException("format == null");
     }
     int bufferSize = format.length() + (args == null ? 0 : args.length * 10);
     Formatter f = new Formatter(new StringBuilder(bufferSize), locale);
     return f.format(format, args).toString();
 }

那么现在问题就来了。但我使用自定义的语言时候(例如,俄语、西班牙语)。使用下面语句转换,小数点会变成逗号

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double dValue = 360.672;
String strValue = String.format("%.2f",dValue);

结果360,672

如果我使用Locale类有定义,就不会出现这种情况。例如中文,英文肯定是正常的。

3、解决办法

分析到这里了,就说一下解决办法。
只好调用这个方法String.format(Locale.ENGLISH,"%.2f",dValue),多了一个参数。自已传进去转换的语言是什么。不再是默认系统语言设置的。因为对于数据,全世界都是通用,那么默认使用英语来转换都没有问题。数据都是这样转换的。

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double dValue = 360.672;
String strValue = String.format(Locale.ENGLISH,"%.2f",dValue);

那么又产生一个问题,同时有转换字符串。这个得注意一下。

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String strResult = String.format("%s:%.3f\r\n", getString(R.string.IteInfoCoorType, 654.76);

这个就要分开转换再接起来,不然都是英文,转换不了其他的语言的。

这个设计上缺陷是否是android sdk 或者jdk的存在bug。我使用都是jdk1.7和sdk 4.2版本。
欢迎大家发现与测试。

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String.format("%.2f",dValue);
String.format(Locale.ENGLISH,"%.2f",dValue);