001/* CharsetProvider.java -- charset service provider interface 002 Copyright (C) 2002, 2006, 2007 Free Software Foundation 003 004This file is part of GNU Classpath. 005 006GNU Classpath is free software; you can redistribute it and/or modify 007it under the terms of the GNU General Public License as published by 008the Free Software Foundation; either version 2, or (at your option) 009any later version. 010 011GNU Classpath is distributed in the hope that it will be useful, but 012WITHOUT ANY WARRANTY; without even the implied warranty of 013MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 014General Public License for more details. 015 016You should have received a copy of the GNU General Public License 017along with GNU Classpath; see the file COPYING. If not, write to the 018Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 01902110-1301 USA. 020 021Linking this library statically or dynamically with other modules is 022making a combined work based on this library. Thus, the terms and 023conditions of the GNU General Public License cover the whole 024combination. 025 026As a special exception, the copyright holders of this library give you 027permission to link this library with independent modules to produce an 028executable, regardless of the license terms of these independent 029modules, and to copy and distribute the resulting executable under 030terms of your choice, provided that you also meet, for each linked 031independent module, the terms and conditions of the license of that 032module. An independent module is a module which is not derived from 033or based on this library. If you modify this library, you may extend 034this exception to your version of the library, but you are not 035obligated to do so. If you do not wish to do so, delete this 036exception statement from your version. */ 037 038package java.nio.charset.spi; 039 040import java.nio.charset.Charset; 041import 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 */ 060public 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