001 /* CharsetProvider.java -- charset service provider interface 002 Copyright (C) 2002, 2006, 2007 Free Software Foundation 003 004 This file is part of GNU Classpath. 005 006 GNU Classpath is free software; you can redistribute it and/or modify 007 it under the terms of the GNU General Public License as published by 008 the Free Software Foundation; either version 2, or (at your option) 009 any later version. 010 011 GNU Classpath is distributed in the hope that it will be useful, but 012 WITHOUT ANY WARRANTY; without even the implied warranty of 013 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 014 General Public License for more details. 015 016 You should have received a copy of the GNU General Public License 017 along with GNU Classpath; see the file COPYING. If not, write to the 018 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 019 02110-1301 USA. 020 021 Linking this library statically or dynamically with other modules is 022 making a combined work based on this library. Thus, the terms and 023 conditions of the GNU General Public License cover the whole 024 combination. 025 026 As a special exception, the copyright holders of this library give you 027 permission to link this library with independent modules to produce an 028 executable, regardless of the license terms of these independent 029 modules, and to copy and distribute the resulting executable under 030 terms of your choice, provided that you also meet, for each linked 031 independent module, the terms and conditions of the license of that 032 module. An independent module is a module which is not derived from 033 or based on this library. If you modify this library, you may extend 034 this exception to your version of the library, but you are not 035 obligated to do so. If you do not wish to do so, delete this 036 exception statement from your version. */ 037 038 package java.nio.charset.spi; 039 040 import java.nio.charset.Charset; 041 import java.util.Iterator; 042 043 044 /** 045 * This class allows an implementor to provide additional character sets. The 046 * subclass must have a nullary constructor, and be attached to charset 047 * implementation classes. These extensions are loaded via the context class 048 * loader. To provide the charset extension, all files named 049 * <code>META-INF/services/java.nio.charset.spi.CharsetProvider</code> are 050 * read from the classpath. Each one should be a UTF-8 encoded list of 051 * fully-qualified names of concrete subclasses of this class; whitespace is 052 * ignored, and '#' starts comments. Duplicates are ignored. The 053 * implementations must be accessible to the classloader that requests them. 054 * 055 * @author Eric Blake (ebb9@email.byu.edu) 056 * @see Charset 057 * @since 1.4 058 * @status updated to 1.4 059 */ 060 public abstract class CharsetProvider 061 { 062 /** 063 * Initialize a new charset provider. This performs a security check on 064 * RuntimePermission("charsetProvider"). 065 * 066 * @throws SecurityException if building a new set is not allowed 067 */ 068 protected CharsetProvider() 069 { 070 // We only do the security check for custom providers, not for the 071 // built in ones. 072 SecurityManager s = System.getSecurityManager(); 073 if (s != null && 074 ! (this instanceof gnu.java.nio.charset.Provider)) 075 // GCJ LOCAL - We have the iconv provider in standard.omit 076 // || this instanceof gnu.java.nio.charset.iconv.IconvProvider)) 077 s.checkPermission(new RuntimePermission("charsetProvider")); 078 } 079 080 /** 081 * Returns an iterator over the charsets defined by this provider. 082 * 083 * @return the iterator 084 * @see Charset#availableCharsets() 085 */ 086 public abstract Iterator<Charset> charsets(); 087 088 /** 089 * Returns the named charset, by canonical name or alias. 090 * 091 * @param name the name of the character 092 * 093 * @return the charset, or null if not supported 094 */ 095 public abstract Charset charsetForName(String name); 096 } // class CharsetProvider