--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/jdk.charsets/share/classes/sun/nio/cs/ext/AbstractCharsetProvider.java Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,206 @@
+/*
+ * Copyright (c) 2000, 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.ext;
+
+import java.lang.ref.SoftReference;
+import java.nio.charset.Charset;
+import java.nio.charset.spi.CharsetProvider;
+import java.util.ArrayList;
+import java.util.TreeMap;
+import java.util.Iterator;
+import java.util.Locale;
+import java.util.Map;
+
+
+/**
+ * Abstract base class for charset providers.
+ *
+ * @author Mark Reinhold
+ */
+
+public class AbstractCharsetProvider
+ extends CharsetProvider
+{
+
+ /* Maps canonical names to class names
+ */
+ private Map<String,String> classMap
+ = new TreeMap<>(String.CASE_INSENSITIVE_ORDER);
+
+ /* Maps alias names to canonical names
+ */
+ private Map<String,String> aliasMap
+ = new TreeMap<>(String.CASE_INSENSITIVE_ORDER);
+
+ /* Maps canonical names to alias-name arrays
+ */
+ private Map<String,String[]> aliasNameMap
+ = new TreeMap<>(String.CASE_INSENSITIVE_ORDER);
+
+ /* Maps canonical names to soft references that hold cached instances
+ */
+ private Map<String,SoftReference<Charset>> cache
+ = new TreeMap<>(String.CASE_INSENSITIVE_ORDER);
+
+ private String packagePrefix;
+
+ protected AbstractCharsetProvider() {
+ packagePrefix = "sun.nio.cs";
+ }
+
+ protected AbstractCharsetProvider(String pkgPrefixName) {
+ packagePrefix = pkgPrefixName;
+ }
+
+ /* Add an entry to the given map, but only if no mapping yet exists
+ * for the given name.
+ */
+ private static <K,V> void put(Map<K,V> m, K name, V value) {
+ if (!m.containsKey(name))
+ m.put(name, value);
+ }
+
+ private static <K,V> void remove(Map<K,V> m, K name) {
+ V x = m.remove(name);
+ assert (x != null);
+ }
+
+ /* Declare support for the given charset
+ */
+ protected void charset(String name, String className, String[] aliases) {
+ synchronized (this) {
+ put(classMap, name, className);
+ for (int i = 0; i < aliases.length; i++)
+ put(aliasMap, aliases[i], name);
+ put(aliasNameMap, name, aliases);
+ cache.clear();
+ }
+ }
+
+ protected void deleteCharset(String name, String[] aliases) {
+ synchronized (this) {
+ remove(classMap, name);
+ for (int i = 0; i < aliases.length; i++)
+ remove(aliasMap, aliases[i]);
+ remove(aliasNameMap, name);
+ cache.clear();
+ }
+ }
+
+ protected boolean hasCharset(String name) {
+ synchronized (this) {
+ return classMap.containsKey(name);
+ }
+ }
+
+ /* Late initialization hook, needed by some providers
+ */
+ protected void init() { }
+
+ private String canonicalize(String charsetName) {
+ String acn = aliasMap.get(charsetName);
+ return (acn != null) ? acn : charsetName;
+ }
+
+ private Charset lookup(String csn) {
+
+ // Check cache first
+ SoftReference<Charset> sr = cache.get(csn);
+ if (sr != null) {
+ Charset cs = sr.get();
+ if (cs != null)
+ return cs;
+ }
+
+ // Do we even support this charset?
+ String cln = classMap.get(csn);
+
+ if (cln == null)
+ return null;
+
+ // Instantiate the charset and cache it
+ try {
+
+ Class<?> c = Class.forName(packagePrefix + "." + cln,
+ true,
+ this.getClass().getClassLoader());
+
+ @SuppressWarnings("deprecation")
+ Charset cs = (Charset)c.newInstance();
+ cache.put(csn, new SoftReference<Charset>(cs));
+ return cs;
+ } catch (ClassNotFoundException x) {
+ return null;
+ } catch (IllegalAccessException x) {
+ return null;
+ } catch (InstantiationException x) {
+ return null;
+ }
+ }
+
+ public final Charset charsetForName(String charsetName) {
+ synchronized (this) {
+ init();
+ return lookup(canonicalize(charsetName));
+ }
+ }
+
+ public final Iterator<Charset> charsets() {
+
+ final ArrayList<String> ks;
+ synchronized (this) {
+ init();
+ ks = new ArrayList<>(classMap.keySet());
+ }
+
+ return new Iterator<Charset>() {
+ Iterator<String> i = ks.iterator();
+
+ public boolean hasNext() {
+ return i.hasNext();
+ }
+
+ public Charset next() {
+ String csn = i.next();
+ synchronized (AbstractCharsetProvider.this) {
+ return lookup(csn);
+ }
+ }
+
+ public void remove() {
+ throw new UnsupportedOperationException();
+ }
+ };
+ }
+
+ public final String[] aliases(String charsetName) {
+ synchronized (this) {
+ init();
+ return aliasNameMap.get(charsetName);
+ }
+ }
+
+}