/* * Copyright 1998-2006 Sun Microsystems, Inc. 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. Sun designates this * particular file as subject to the "Classpath" exception as provided * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, * CA 95054 USA or visit www.sun.com if you need additional information or * have any questions. */ package sun.io; import java.io.UnsupportedEncodingException; import java.lang.ref.SoftReference; import java.util.Properties; /** * Package-private utility class that caches the default converter classes and * provides other logic common to both the ByteToCharConverter and * CharToByteConverter classes. * * @author Mark Reinhold * @since 1.2 * * @deprecated Replaced by {@link java.nio.charset}. THIS API WILL BE * REMOVED IN J2SE 1.6. */ @Deprecated public class Converters { private Converters() { } /* To prevent instantiation */ /* Lock for all static fields in this class */ private static Object lock = Converters.class; /* Cached values of system properties */ private static String converterPackageName = null; /* file.encoding.pkg */ private static String defaultEncoding = null; /* file.encoding */ /* Converter type constants and names */ public static final int BYTE_TO_CHAR = 0; public static final int CHAR_TO_BYTE = 1; private static final String[] converterPrefix = { "ByteToChar", "CharToByte" }; // -- Converter class cache -- private static final int CACHE_SIZE = 3; /* For the default charset, whatever it turns out to be */ private static final Object DEFAULT_NAME = new Object(); /* Cached converter classes, CACHE_SIZE per converter type. Each cache * entry is a soft reference to a two-object array; the first element of * the array is the converter class, the second is an object (typically a * string) representing the encoding name that was used to request the * converter, e.g., * * ((Object[])classCache[CHAR_TO_BYTE][i].get())[0] * * will be a CharToByteConverter and * * ((Object[])classCache[CHAR_TO_BYTE][i].get())[1] * * will be the string encoding name used to request it, assuming that cache * entry i is valid. * * Ordinarily we'd do this with a private static utility class, but since * this code can be involved in the startup sequence it's important to keep * the footprint down. */ @SuppressWarnings("unchecked") private static SoftReference[][] classCache = (SoftReference[][]) new SoftReference[][] { new SoftReference[CACHE_SIZE], new SoftReference[CACHE_SIZE] }; private static void moveToFront(Object[] oa, int i) { Object ob = oa[i]; for (int j = i; j > 0; j--) oa[j] = oa[j - 1]; oa[0] = ob; } private static Class cache(int type, Object encoding) { SoftReference[] srs = classCache[type]; for (int i = 0; i < CACHE_SIZE; i++) { SoftReference sr = srs[i]; if (sr == null) continue; Object[] oa = sr.get(); if (oa == null) { srs[i] = null; continue; } if (oa[1].equals(encoding)) { moveToFront(srs, i); return (Class)oa[0]; } } return null; } private static Class cache(int type, Object encoding, Class c) { SoftReference[] srs = classCache[type]; srs[CACHE_SIZE - 1] = new SoftReference(new Object[] { c, encoding }); moveToFront(srs, CACHE_SIZE - 1); return c; } /* Used to avoid doing expensive charset lookups for charsets that are not * yet directly supported by NIO. */ public static boolean isCached(int type, String encoding) { synchronized (lock) { SoftReference[] srs = classCache[type]; for (int i = 0; i < CACHE_SIZE; i++) { SoftReference sr = srs[i]; if (sr == null) continue; Object[] oa = sr.get(); if (oa == null) { srs[i] = null; continue; } if (oa[1].equals(encoding)) return true; } return false; } } /** Get the name of the converter package */ private static String getConverterPackageName() { String cp = converterPackageName; if (cp != null) return cp; java.security.PrivilegedAction pa = new sun.security.action.GetPropertyAction("file.encoding.pkg"); cp = java.security.AccessController.doPrivileged(pa); if (cp != null) { /* Property is set, so take it as the true converter package */ converterPackageName = cp; } else { /* Fall back to sun.io */ cp = "sun.io"; } return cp; } public static String getDefaultEncodingName() { synchronized (lock) { if (defaultEncoding == null) { java.security.PrivilegedAction pa = new sun.security.action.GetPropertyAction("file.encoding"); defaultEncoding = java.security.AccessController.doPrivileged(pa); } } return defaultEncoding; } public static void resetDefaultEncodingName() { // This method should only be called during VM initialization. if (sun.misc.VM.isBooted()) return; synchronized (lock) { defaultEncoding = "ISO-8859-1"; Properties p = System.getProperties(); p.setProperty("file.encoding", defaultEncoding); System.setProperties(p); } } /** * Get the class that implements the given type of converter for the named * encoding, or throw an UnsupportedEncodingException if no such class can * be found */ private static Class getConverterClass(int type, String encoding) throws UnsupportedEncodingException { String enc = null; /* "ISO8859_1" is the canonical name for the ISO-Latin-1 encoding. Native code in the JDK commonly uses the alias "8859_1" instead of "ISO8859_1". We hardwire this alias here in order to avoid loading the full alias table just for this case. */ if (!encoding.equals("ISO8859_1")) { if (encoding.equals("8859_1")) { enc = "ISO8859_1"; /* * On Solaris with nl_langinfo() called in GetJavaProperties(): * * locale undefined -> NULL -> hardcoded default * "C" locale -> "" -> hardcoded default (on 2.6) * "C" locale -> "646" (on 2.7) * "en_US" locale -> "ISO8859-1" * "en_GB" locale -> "ISO8859-1" (on 2.7) * "en_UK" locale -> "ISO8859-1" (on 2.6) */ } else if (encoding.equals("ISO8859-1")) { enc = "ISO8859_1"; } else if (encoding.equals("646")) { enc = "ASCII"; } else { enc = CharacterEncoding.aliasName(encoding); } } if (enc == null) { enc = encoding; } try { return Class.forName(getConverterPackageName() + "." + converterPrefix[type] + enc); } catch(ClassNotFoundException e) { throw new UnsupportedEncodingException(enc); } } /** * Instantiate the given converter class, or throw an * UnsupportedEncodingException if it cannot be instantiated */ private static Object newConverter(String enc, Class c) throws UnsupportedEncodingException { try { return c.newInstance(); } catch(InstantiationException e) { throw new UnsupportedEncodingException(enc); } catch(IllegalAccessException e) { throw new UnsupportedEncodingException(enc); } } /** * Create a converter object that implements the given type of converter * for the given encoding, or throw an UnsupportedEncodingException if no * appropriate converter class can be found and instantiated */ static Object newConverter(int type, String enc) throws UnsupportedEncodingException { Class c; synchronized (lock) { c = cache(type, enc); if (c == null) { c = getConverterClass(type, enc); if (!c.getName().equals("sun.io.CharToByteUTF8")) cache(type, enc, c); } } return newConverter(enc, c); } /** * Find the class that implements the given type of converter for the * default encoding. If the default encoding cannot be determined or is * not yet defined, return a class that implements the fallback default * encoding, which is just ISO 8859-1. */ private static Class getDefaultConverterClass(int type) { boolean fillCache = false; Class c; /* First check the class cache */ c = cache(type, DEFAULT_NAME); if (c != null) return c; /* Determine the encoding name */ String enc = getDefaultEncodingName(); if (enc != null) { /* file.encoding has been set, so cache the converter class */ fillCache = true; } else { /* file.encoding has not been set, so use a default encoding which will not be cached */ enc = "ISO8859_1"; } /* We have an encoding name; try to find its class */ try { c = getConverterClass(type, enc); if (fillCache) { cache(type, DEFAULT_NAME, c); } } catch (UnsupportedEncodingException x) { /* Can't find the default class, so fall back to ISO 8859-1 */ try { c = getConverterClass(type, "ISO8859_1"); } catch (UnsupportedEncodingException y) { throw new InternalError("Cannot find default " + converterPrefix[type] + " converter class"); } } return c; } /** * Create a converter object that implements the given type of converter * for the default encoding, falling back to ISO 8859-1 if the default * encoding cannot be determined. */ static Object newDefaultConverter(int type) { Class c; synchronized (lock) { c = getDefaultConverterClass(type); } try { return newConverter("", c); } catch (UnsupportedEncodingException x) { throw new InternalError("Cannot instantiate default converter" + " class " + c.getName()); } } }