diff -r 000000000000 -r 959103a6100f src/share/classes/com/sun/tools/javac/api/Formattable.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/share/classes/com/sun/tools/javac/api/Formattable.java	Wed Apr 27 01:34:52 2016 +0800
@@ -0,0 +1,76 @@
+/*
+ * Copyright (c) 2008, 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 com.sun.tools.javac.api;
+
+import java.util.Locale;
+
+/**
+ * This interface must be implemented by any javac class that has non-trivial
+ * formatting needs (e.g. where toString() does not apply because of localization).
+ *
+ * <p><b>This is NOT part of any supported API.
+ * If you write code that depends on this, you do so at your own risk.
+ * This code and its internal interfaces are subject to change or
+ * deletion without notice.</b>
+ *
+ * @author Maurizio Cimadamore
+ */
+public interface Formattable {
+
+    /**
+     * Used to obtain a localized String representing the object accordingly
+     * to a given locale
+     *
+     * @param locale locale in which the object's representation is to be rendered
+     * @param messages messages object used for localization
+     * @return a locale-dependent string representing the object
+     */
+    public String toString(Locale locale, Messages messages);
+    /**
+     * Retrieve a pretty name of this object's kind
+     * @return a string representing the object's kind
+     */
+    String getKind();
+
+    static class LocalizedString implements Formattable {
+        String key;
+
+        public LocalizedString(String key) {
+            this.key = key;
+        }
+
+        public String toString(java.util.Locale l, Messages messages) {
+            return messages.getLocalizedString(l, key);
+        }
+        public String getKind() {
+            return "LocalizedString";
+        }
+
+        public String toString() {
+            return key;
+        }
+    }
+}