| /* |
| * Copyright (c) 2000, 2013, 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.nio.charset.spi; |
| |
| import java.nio.charset.Charset; |
| import java.util.Iterator; |
| |
| |
| /** |
| * Charset service-provider class. |
| * |
| * <p> A charset provider is a concrete subclass of this class that has a |
| * zero-argument constructor and some number of associated charset |
| * implementation classes. Charset providers may be installed in an instance |
| * of the Java platform as extensions. Providers may also be made available by |
| * adding them to the applet or application class path or by some other |
| * platform-specific means. Charset providers are looked up via the current |
| * thread's {@link java.lang.Thread#getContextClassLoader() context class |
| * loader}. |
| * |
| * <p> A charset provider identifies itself with a provider-configuration file |
| * named {@code java.nio.charset.spi.CharsetProvider} in the resource |
| * directory {@code META-INF/services}. The file should contain a list of |
| * fully-qualified concrete charset-provider class names, one per line. A line |
| * is terminated by any one of a line feed ({@code '\n'}), a carriage return |
| * ({@code '\r'}), or a carriage return followed immediately by a line feed. |
| * Space and tab characters surrounding each name, as well as blank lines, are |
| * ignored. The comment character is {@code '#'} (<code>'\u0023'</code>); on |
| * each line all characters following the first comment character are ignored. |
| * The file must be encoded in UTF-8. |
| * |
| * <p> If a particular concrete charset provider class is named in more than |
| * one configuration file, or is named in the same configuration file more than |
| * once, then the duplicates will be ignored. The configuration file naming a |
| * particular provider need not be in the same jar file or other distribution |
| * unit as the provider itself. The provider must be accessible from the same |
| * class loader that was initially queried to locate the configuration file; |
| * this is not necessarily the class loader that loaded the file. </p> |
| * |
| * |
| * @author Mark Reinhold |
| * @author JSR-51 Expert Group |
| * @since 1.4 |
| * |
| * @see java.nio.charset.Charset |
| */ |
| |
| public abstract class CharsetProvider { |
| |
| private static Void checkPermission() { |
| SecurityManager sm = System.getSecurityManager(); |
| if (sm != null) |
| sm.checkPermission(new RuntimePermission("charsetProvider")); |
| return null; |
| } |
| private CharsetProvider(Void ignore) { } |
| |
| /** |
| * Initializes a new charset provider. |
| * |
| * @throws SecurityException |
| * If a security manager has been installed and it denies |
| * {@link RuntimePermission}{@code ("charsetProvider")} |
| */ |
| protected CharsetProvider() { |
| this(checkPermission()); |
| } |
| |
| /** |
| * Creates an iterator that iterates over the charsets supported by this |
| * provider. This method is used in the implementation of the {@link |
| * java.nio.charset.Charset#availableCharsets Charset.availableCharsets} |
| * method. |
| * |
| * @return The new iterator |
| */ |
| public abstract Iterator<Charset> charsets(); |
| |
| /** |
| * Retrieves a charset for the given charset name. |
| * |
| * @param charsetName |
| * The name of the requested charset; may be either |
| * a canonical name or an alias |
| * |
| * @return A charset object for the named charset, |
| * or {@code null} if the named charset |
| * is not supported by this provider |
| */ |
| public abstract Charset charsetForName(String charsetName); |
| |
| } |