--- a/jdk/src/java.base/share/classes/sun/util/locale/LocaleMatcher.java	Tue Nov 08 06:22:31 2016 +0000
+++ b/jdk/src/java.base/share/classes/sun/util/locale/LocaleMatcher.java	Tue Nov 08 14:48:55 2016 +0530
@@ -365,7 +365,7 @@
                 continue;
             }
 
-            String rangeForRegex = range.replaceAll("\\x2A", "\\\\p{Alnum}*");
+            String rangeForRegex = range.replace("*", "\\p{Alnum}*");
             while (rangeForRegex.length() > 0) {
                 for (String tag : tags) {
                     tag = tag.toLowerCase(Locale.ROOT);
@@ -399,7 +399,7 @@
                 continue;
             }
 
-            String rangeForRegex = range.replaceAll("\\x2A", "\\\\p{Alnum}*");
+            String rangeForRegex = range.replace("*", "\\p{Alnum}*");
             while (rangeForRegex.length() > 0) {
                 if (tag.matches(rangeForRegex)) {
                     return true;
@@ -447,7 +447,7 @@
     }
 
     public static List<LanguageRange> parse(String ranges) {
-        ranges = ranges.replaceAll(" ", "").toLowerCase(Locale.ROOT);
+        ranges = ranges.replace(" ", "").toLowerCase(Locale.ROOT);
         if (ranges.startsWith("accept-language:")) {
             ranges = ranges.substring(16); // delete unnecessary prefix
         }
@@ -536,6 +536,21 @@
         return list;
     }
 
+    /**
+     * A faster alternative approach to String.replaceFirst(), if the given
+     * string is a literal String, not a regex.
+     */
+    private static String replaceFirstSubStringMatch(String range,
+            String substr, String replacement) {
+        int pos = range.indexOf(substr);
+        if (pos == -1) {
+            return range;
+        } else {
+            return range.substring(0, pos) + replacement
+                    + range.substring(pos + substr.length());
+        }
+    }
+
     private static String[] getEquivalentsForLanguage(String range) {
         String r = range;
 
@@ -544,13 +559,16 @@
                 String equiv = LocaleEquivalentMaps.singleEquivMap.get(r);
                 // Return immediately for performance if the first matching
                 // subtag is found.
-                return new String[] {range.replaceFirst(r, equiv)};
+                return new String[]{replaceFirstSubStringMatch(range,
+                    r, equiv)};
             } else if (LocaleEquivalentMaps.multiEquivsMap.containsKey(r)) {
                 String[] equivs = LocaleEquivalentMaps.multiEquivsMap.get(r);
+                String[] result = new String[equivs.length];
                 for (int i = 0; i < equivs.length; i++) {
-                    equivs[i] = range.replaceFirst(r, equivs[i]);
+                    result[i] = replaceFirstSubStringMatch(range,
+                            r, equivs[i]);
                 }
-                return equivs;
+                return result;
             }
 
             // Truncate the last subtag simply.
@@ -578,7 +596,9 @@
 
                 int len = index + subtag.length();
                 if (range.length() == len || range.charAt(len) == '-') {
-                    return range.replaceFirst(subtag, LocaleEquivalentMaps.regionVariantEquivMap.get(subtag));
+                    return replaceFirstSubStringMatch(range, subtag,
+                            LocaleEquivalentMaps.regionVariantEquivMap
+                                    .get(subtag));
                 }
             }
         }

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/test/java/util/Locale/Bug8166994.java	Tue Nov 08 14:48:55 2016 +0530
@@ -0,0 +1,74 @@
+/*
+ * Copyright (c) 2016, 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.
+ *
+ * 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.
+ */
+/*
+ * @test
+ * @bug 8166884
+ * @summary Checks the subsequent call to parse the same language ranges
+ *          which must generate the same list of language ranges
+ *          i.e. the priority list containing equivalents, as in the
+ *          first call
+ */
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.Locale;
+import java.util.stream.Collectors;
+
+public class Bug8166994 {
+
+    public static void main(String[] args) {
+        List<String> list = Arrays.asList("ccq-aa", "ybd-aa", "rki-aa");
+        String ranges = "ccq-aa";
+        testParseConsistency(list, ranges);
+
+        // consecutive call to check the language range parse consistency
+        testParseConsistency(list, ranges);
+
+        // another case with ranges consisting of multiple equivalents and
+        // single equivalents
+        list = Arrays.asList("gfx-xz", "oun-xz", "mwj-xz", "vaj-xz",
+                "taj-xy", "tsf-xy");
+        ranges = "gfx-xz, taj-xy";
+        testParseConsistency(list, ranges);
+        // consecutive call to check the language range parse consistency
+        testParseConsistency(list, ranges);
+
+    }
+
+    private static void testParseConsistency(List<String> list, String ranges) {
+        List<String> priorityList = parseRanges(ranges);
+        if (!list.equals(priorityList)) {
+            throw new RuntimeException("Failed to parse the language range ["
+                    + ranges + "], Expected: " + list + " Found: "
+                    + priorityList);
+        }
+    }
+
+    private static List<String> parseRanges(String s) {
+        return Locale.LanguageRange.parse(s).stream()
+                .map(Locale.LanguageRange::getRange)
+                .collect(Collectors.toList());
+    }
+
+}
+