Java tutorial
/* * Copyright (c) 2005, 2012, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package java.util.spi; import java.util.Arrays; import java.util.Currency; import java.util.List; import java.util.Locale; import java.util.ResourceBundle.Control; /** * An abstract class for service providers that * provide localized currency symbols and display names for the * {@link java.util.Currency Currency} class. * Note that currency symbols are considered names when determining * behaviors described in the * {@link java.util.spi.LocaleServiceProvider LocaleServiceProvider} * specification. * * @since 1.6 */ public abstract class CurrencyNameProvider extends LocaleServiceProvider { /** * Sole constructor. (For invocation by subclass constructors, typically * implicit.) */ protected CurrencyNameProvider() { } /** * Gets the symbol of the given currency code for the specified locale. * For example, for "USD" (US Dollar), the symbol is "$" if the specified * locale is the US, while for other locales it may be "US$". If no * symbol can be determined, null should be returned. * * @param currencyCode the ISO 4217 currency code, which * consists of three upper-case letters between 'A' (U+0041) and * 'Z' (U+005A) * @param locale the desired locale * @return the symbol of the given currency code for the specified locale, or null if * the symbol is not available for the locale * @exception NullPointerException if <code>currencyCode</code> or * <code>locale</code> is null * @exception IllegalArgumentException if <code>currencyCode</code> is not in * the form of three upper-case letters, or <code>locale</code> isn't * one of the locales returned from * {@link java.util.spi.LocaleServiceProvider#getAvailableLocales() * getAvailableLocales()}. * @see java.util.Currency#getSymbol(java.util.Locale) */ public abstract String getSymbol(String currencyCode, Locale locale); /** * Returns a name for the currency that is appropriate for display to the * user. The default implementation returns null. * * @param currencyCode the ISO 4217 currency code, which * consists of three upper-case letters between 'A' (U+0041) and * 'Z' (U+005A) * @param locale the desired locale * @return the name for the currency that is appropriate for display to the * user, or null if the name is not available for the locale * @exception IllegalArgumentException if <code>currencyCode</code> is not in * the form of three upper-case letters, or <code>locale</code> isn't * one of the locales returned from * {@link java.util.spi.LocaleServiceProvider#getAvailableLocales() * getAvailableLocales()}. * @exception NullPointerException if <code>currencyCode</code> or * <code>locale</code> is <code>null</code> * @since 1.7 */ public String getDisplayName(String currencyCode, Locale locale) { if (currencyCode == null || locale == null) { throw new NullPointerException(); } // Check whether the currencyCode is valid char[] charray = currencyCode.toCharArray(); if (charray.length != 3) { throw new IllegalArgumentException("The currencyCode is not in the form of three upper-case letters."); } for (char c : charray) { if (c < 'A' || c > 'Z') { throw new IllegalArgumentException( "The currencyCode is not in the form of three upper-case letters."); } } // Check whether the locale is valid Control c = Control.getNoFallbackControl(Control.FORMAT_DEFAULT); for (Locale l : getAvailableLocales()) { if (c.getCandidateLocales("", l).contains(locale)) { return null; } } throw new IllegalArgumentException("The locale is not available"); } }