如何获得可用的国家和货币？

Question

我尝试同时获取所有可用国家和货币的列表。我希望国家名称出现在微调器上，当用户选择国家时，它是 return 货币符号。我的方法有效，但我认为这是非常糟糕的做法，因为加载数据大约需要 3-2 秒。我是这样做的：

  public ArrayList<CurrencyModel> getCountriesAndCurrency(){
        ArrayList<CurrencyModel> result = new ArrayList<>();
        ArrayList<Locale> list = new ArrayList<>(Arrays.asList(Locale.getAvailableLocales()));
        for (int i = 0; i <list.size(); i++) {
            String country = list.get(i).getDisplayCountry();
            try {
                Locale pickedLocal = new Locale(list.get(i).getISO3Language(), list.get(i).getCountry());
                String code = Currency.getInstance(pickedLocal).getCurrencyCode();
                Currency currency = Currency.getInstance(code);
                String currencySymbol = currency.getSymbol(pickedLocal);
                if(currencySymbol.length()>1){
                    currencySymbol = currency.getSymbol();
                }
                result.add(new CurrencyModel(list.get(i), country, currencySymbol));
            } catch (Exception e) {
            }
        }
        Collections.sort(result, new CustomComparator());
        ArrayList<CurrencyModel> finalRes = new ArrayList<>();
        for (int i = 0; i < result.size(); i++) {
            try {
                if(!result.get(i).getCountryName().equals(result.get((i+1)).getCountryName())) {
                    finalRes.add(result.get(i));
                }
            }catch (Exception e){}
        }
        Collections.sort(finalRes, new CustomComparator());
        return finalRes;
    }

    public class CustomComparator implements Comparator<CurrencyModel> {
        @Override
        public int compare(CurrencyModel o1, CurrencyModel o2) {
            return o1.getCountryName().compareTo(o2.getCountryName());
        }
    }

CurrencyModel 对象是 = locale locale ,String countryName , String currencySymbol。

这个动作有更好的解决方案吗？

Answer 1

发现有几件事可以帮助您不确定他们是否会显着提高结果

1- 语言环境重新实例化 Locale pickedLocal = new Locale(list.get(i).getISO3Language(), list.get(i).getCountry()); 为什么要使用 locale 属性重新创建 locale ？你只需要分配它：

Locale pickedLocal = list.get(i);

2- 货币相同，

String code = Currency.getInstance(pickedLocal).getCurrencyCode();
Currency currency = Currency.getInstance(code);
String currencySymbol = currency.getSymbol(pickedLocal);

据我所知，你的目标是 currencySymbol，所以就这样做吧：

String currencySymbol = Currency.getInstance(pickedLocal).getSymbol();

因此最后的代码块（带有 try-catch 的代码块）应该如下所示

try {
    Locale pickedLocal = list.get(i);
    String currencySymbol = Currency.getInstance(pickedLocal).getSymbol();
    if(currencySymbol.length()>1){
        currencySymbol = currency.getSymbol();
    }
    result.add(new CurrencyModel(pickedLocal, country, currencySymbol));
} catch (Exception e) {
}

在 result.add(new CurrencyModel(list.get(i),... 使用 pickedLocal，不要从列表中重新获取项目。

这就是我到目前为止所得到的，我将在这个答案中附加任何进一步的发现。

编辑：（也许您必须先对邮件 "list" 进行排序） 再次查看代码，我发现您在填充结果列表后尝试删除重复项，如果您在添加新项目之前检查结果列表，您将摆脱第二个循环

try {
    Locale pickedLocal = list.get(i);
    String currencySymbol = Currency.getInstance(pickedLocal).getSymbol();
    if(currencySymbol.length()>1){
        currencySymbol = currency.getSymbol();
    }

    //TO AVOID the second loop (check duplicates), add only if not exist
    final int size = result.size();
    if(size > 0){
        if(!result.get(size-1).getCountryName().equals(country)){
            //no similar item was added yet, so add the new item
            result.add(new CurrencyModel(pickedLocal, country, currencySymbol));
        }
    }else{
        //it still empty, just add the new item
        result.add(new CurrencyModel(pickedLocal, country, currencySymbol));
    }
} catch (Exception e) {
}

如何获得可用的国家和货币？

How to get available countries and Currencies?

android

locale

currency