| /* |
| * Copyright (c) 2004, 2011, 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 sun.nio.cs; |
| |
| import java.nio.charset.Charset; |
| import java.nio.charset.spi.CharsetProvider; |
| import java.util.Iterator; |
| import java.util.Map; |
| |
| |
| /** |
| * Abstract base class for fast charset providers. |
| * |
| * @author Mark Reinhold |
| */ |
| |
| public class FastCharsetProvider |
| extends CharsetProvider |
| { |
| |
| // Maps canonical names to class names |
| private Map<String,String> classMap; |
| |
| // Maps alias names to canonical names |
| private Map<String,String> aliasMap; |
| |
| // Maps canonical names to cached instances |
| private Map<String,Charset> cache; |
| |
| private String packagePrefix; |
| |
| protected FastCharsetProvider(String pp, |
| Map<String,String> am, |
| Map<String,String> cm, |
| Map<String,Charset> c) |
| { |
| packagePrefix = pp; |
| aliasMap = am; |
| classMap = cm; |
| cache = c; |
| } |
| |
| private String canonicalize(String csn) { |
| String acn = aliasMap.get(csn); |
| return (acn != null) ? acn : csn; |
| } |
| |
| // Private ASCII-only version, optimized for interpretation during startup |
| // |
| private static String toLower(String s) { |
| int n = s.length(); |
| boolean allLower = true; |
| for (int i = 0; i < n; i++) { |
| int c = s.charAt(i); |
| if (((c - 'A') | ('Z' - c)) >= 0) { |
| allLower = false; |
| break; |
| } |
| } |
| if (allLower) |
| return s; |
| char[] ca = new char[n]; |
| for (int i = 0; i < n; i++) { |
| int c = s.charAt(i); |
| if (((c - 'A') | ('Z' - c)) >= 0) |
| ca[i] = (char)(c + 0x20); |
| else |
| ca[i] = (char)c; |
| } |
| return new String(ca); |
| } |
| |
| private Charset lookup(String charsetName) { |
| |
| String csn = canonicalize(toLower(charsetName)); |
| |
| // Check cache first |
| Charset cs = cache.get(csn); |
| if (cs != null) |
| return cs; |
| |
| // Do we even support this charset? |
| String cln = classMap.get(csn); |
| if (cln == null) |
| return null; |
| |
| if (cln.equals("US_ASCII")) { |
| cs = new US_ASCII(); |
| cache.put(csn, cs); |
| return cs; |
| } |
| |
| // Instantiate the charset and cache it |
| try { |
| @SuppressWarnings("deprecation") |
| Object o= Class.forName(packagePrefix + "." + cln, |
| true, |
| this.getClass().getClassLoader()).newInstance(); |
| cs = (Charset)o; |
| cache.put(csn, cs); |
| return cs; |
| } catch (ClassNotFoundException | |
| IllegalAccessException | |
| InstantiationException x) { |
| return null; |
| } |
| } |
| |
| public final Charset charsetForName(String charsetName) { |
| synchronized (this) { |
| return lookup(canonicalize(charsetName)); |
| } |
| } |
| |
| public final Iterator<Charset> charsets() { |
| |
| return new Iterator<Charset>() { |
| |
| Iterator<String> i = classMap.keySet().iterator(); |
| |
| public boolean hasNext() { |
| return i.hasNext(); |
| } |
| |
| public Charset next() { |
| String csn = i.next(); |
| return lookup(csn); |
| } |
| |
| public void remove() { |
| throw new UnsupportedOperationException(); |
| } |
| |
| }; |
| |
| } |
| |
| } |