Currencies.java

package de.invesdwin.util.lang;

import java.nio.ByteBuffer;
import java.text.NumberFormat;
import java.util.Currency;
import java.util.HashMap;
import java.util.Locale;
import java.util.Map;
import java.util.Map.Entry;

import javax.annotation.concurrent.Immutable;

import de.invesdwin.util.math.decimal.Decimal;

@Immutable
public final class Currencies {

    public static final String CNY_SYMBOL = "元";
    public static final String JPY_SYMBOL = "¥";
    public static final String GBP_SYMBOL = "£";
    public static final String EUR_SYMBOL = "€";
    public static final String USD_SYMBOL = "$";

    public static final Currency ARS = Currency.getInstance("ARS");
    public static final Currency AUD = Currency.getInstance("AUD");
    public static final Currency BGN = Currency.getInstance("BGN");
    public static final Currency BRL = Currency.getInstance("BRL");
    public static final Currency CAD = Currency.getInstance("CAD");
    public static final Currency CHF = Currency.getInstance("CHF");
    public static final Currency CNY = Currency.getInstance("CNY");
    public static final Currency CZK = Currency.getInstance("CZK");
    public static final Currency DKK = Currency.getInstance("DKK");
    public static final Currency EUR = Currency.getInstance("EUR");
    public static final Currency GBP = Currency.getInstance("GBP");
    public static final Currency HKD = Currency.getInstance("HKD");
    public static final Currency HUF = Currency.getInstance("HUF");
    public static final Currency INR = Currency.getInstance("INR");
    public static final Currency JPY = Currency.getInstance("JPY");
    public static final Currency MXN = Currency.getInstance("MXN");
    public static final Currency NOK = Currency.getInstance("NOK");
    public static final Currency NZD = Currency.getInstance("NZD");
    public static final Currency PLN = Currency.getInstance("PLN");
    public static final Currency RON = Currency.getInstance("RON");
    public static final Currency RUB = Currency.getInstance("RUB");
    public static final Currency SAR = Currency.getInstance("SAR");
    public static final Currency SEK = Currency.getInstance("SEK");
    public static final Currency SGD = Currency.getInstance("SGD");
    public static final Currency TRY = Currency.getInstance("TRY");
    public static final Currency TWD = Currency.getInstance("TWD");
    public static final Currency USD = Currency.getInstance("USD");
    public static final Currency ZAR = Currency.getInstance("ZAR");

    private static final Map<String, String> CURRENCY_CODE_2_CURRENCY_SYMBOL = new HashMap<String, String>();

    static {
        //only put commonly (internationally) known symbols here
        CURRENCY_CODE_2_CURRENCY_SYMBOL.put("USD", USD_SYMBOL);
        CURRENCY_CODE_2_CURRENCY_SYMBOL.put("EUR", EUR_SYMBOL);
        CURRENCY_CODE_2_CURRENCY_SYMBOL.put("GBP", GBP_SYMBOL);
        CURRENCY_CODE_2_CURRENCY_SYMBOL.put("JPY", JPY_SYMBOL);
        CURRENCY_CODE_2_CURRENCY_SYMBOL.put("CNY", CNY_SYMBOL);
    }

    private Currencies() {}

    /**
     * This method uses symbols for the most common currencies.
     * 
     * This results in: 1,212.12 € or 1,212.12 CNY
     * 
     * The symbol is put behind the number with a space, to increase readability in tables.
     */
    public static String formatMoney(final Locale locale, final String currencyCode, final Decimal price) {
        final NumberFormat nf = NumberFormat.getNumberInstance(locale);
        nf.setMinimumFractionDigits(2);
        nf.setMaximumFractionDigits(2);
        String str = nf.format(price);
        str += " " + formatCurrencyCode(currencyCode);
        return str;
    }

    public static String formatCurrencyCode(final String currencyCode) {
        final String currencySymbol = CURRENCY_CODE_2_CURRENCY_SYMBOL.get(currencyCode);
        if (currencySymbol != null) {
            return currencySymbol;
        } else {
            return currencyCode;
        }
    }

    public static String replaceCurrencySymbolsWithCurrencyCode(final String str) {
        String replaced = str;
        for (final Entry<String, String> entry : CURRENCY_CODE_2_CURRENCY_SYMBOL.entrySet()) {
            final String code = entry.getKey();
            final String symbol = entry.getValue();
            replaced = replaced.replace(symbol, code);
        }
        return replaced;
    }

    public static Currency getInstance(final String currencyCode) {
        try {
            return Currency.getInstance(currencyCode);
        } catch (final Throwable t) {
            throw new RuntimeException("On: " + currencyCode, t);
        }
    }

    public static Currency getInstanceOrNull(final String currencyCode) {
        try {
            return Currency.getInstance(currencyCode);
        } catch (final Throwable t) {
            return null;
        }
    }

    public static void putCurrency(final ByteBuffer buffer, final Currency currency) {
        if (currency == null) {
            buffer.put("___".getBytes());
        } else {
            buffer.put(currency.getCurrencyCode().getBytes());
        }
    }

    public static Currency extractCurrency(final ByteBuffer buffer, final int index) {
        final byte[] bytes = new byte[3];
        buffer.get(bytes);
        final String currencyCode = new String(bytes);
        if ("___".equals(currencyCode)) {
            return null;
        } else {
            return getInstance(currencyCode);
        }
    }

}