diff -r 000000000000 -r 959103a6100f src/share/classes/com/sun/tools/doclets/formats/html/AbstractTreeWriter.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/share/classes/com/sun/tools/doclets/formats/html/AbstractTreeWriter.java	Wed Apr 27 01:34:52 2016 +0800
@@ -0,0 +1,185 @@
+/*
+ * Copyright (c) 1998, 2013, 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.doclets.formats.html;
+
+import java.io.*;
+import java.util.*;
+
+import com.sun.javadoc.*;
+import com.sun.tools.doclets.formats.html.markup.*;
+import com.sun.tools.doclets.internal.toolkit.*;
+import com.sun.tools.doclets.internal.toolkit.util.*;
+
+/**
+ * Abstract class to print the class hierarchy page for all the Classes. This
+ * is sub-classed by {@link PackageTreeWriter} and {@link TreeWriter} to
+ * generate the Package Tree and global Tree(for all the classes and packages)
+ * pages.
+ *
+ *  <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 Atul M Dambalkar
+ */
+public abstract class AbstractTreeWriter extends HtmlDocletWriter {
+
+    /**
+     * The class and interface tree built by using {@link ClassTree}
+     */
+    protected final ClassTree classtree;
+
+    private static final String LI_CIRCLE  = "circle";
+
+    /**
+     * Constructor initializes classtree variable. This constructor will be used
+     * while generating global tree file "overview-tree.html".
+     *
+     * @param configuration  The current configuration
+     * @param filename   File to be generated.
+     * @param classtree  Tree built by {@link ClassTree}.
+     * @throws IOException
+     * @throws DocletAbortException
+     */
+    protected AbstractTreeWriter(ConfigurationImpl configuration,
+                                 DocPath filename, ClassTree classtree)
+                                 throws IOException {
+        super(configuration, filename);
+        this.classtree = classtree;
+    }
+
+    /**
+     * Add each level of the class tree. For each sub-class or
+     * sub-interface indents the next level information.
+     * Recurses itself to add subclasses info.
+     *
+     * @param parent the superclass or superinterface of the list
+     * @param list list of the sub-classes at this level
+     * @param isEnum true if we are generating a tree for enums
+     * @param contentTree the content tree to which the level information will be added
+     */
+    protected void addLevelInfo(ClassDoc parent, List<ClassDoc> list,
+            boolean isEnum, Content contentTree) {
+        int size = list.size();
+        if (size > 0) {
+            Content ul = new HtmlTree(HtmlTag.UL);
+            for (int i = 0; i < size; i++) {
+                ClassDoc local = list.get(i);
+                HtmlTree li = new HtmlTree(HtmlTag.LI);
+                li.addAttr(HtmlAttr.TYPE, LI_CIRCLE);
+                addPartialInfo(local, li);
+                addExtendsImplements(parent, local, li);
+                addLevelInfo(local, classtree.subs(local, isEnum),
+                        isEnum, li);   // Recurse
+                ul.addContent(li);
+            }
+            contentTree.addContent(ul);
+        }
+    }
+
+    /**
+     * Add the heading for the tree depending upon tree type if it's a
+     * Class Tree or Interface tree.
+     *
+     * @param list List of classes which are at the most base level, all the
+     * other classes in this run will derive from these classes
+     * @param heading heading for the tree
+     * @param div the content tree to which the tree will be added
+     */
+    protected void addTree(List<ClassDoc> list, String heading, Content div) {
+        if (list.size() > 0) {
+            ClassDoc firstClassDoc = list.get(0);
+            Content headingContent = getResource(heading);
+            div.addContent(HtmlTree.HEADING(HtmlConstants.CONTENT_HEADING, true,
+                    headingContent));
+            addLevelInfo(!firstClassDoc.isInterface()? firstClassDoc : null,
+                    list, list == classtree.baseEnums(), div);
+        }
+    }
+
+    /**
+     * Add information regarding the classes which this class extends or
+     * implements.
+     *
+     * @param parent the parent class of the class being documented
+     * @param cd the classdoc under consideration
+     * @param contentTree the content tree to which the information will be added
+     */
+    protected void addExtendsImplements(ClassDoc parent, ClassDoc cd,
+            Content contentTree) {
+        ClassDoc[] interfaces = cd.interfaces();
+        if (interfaces.length > (cd.isInterface()? 1 : 0)) {
+            Arrays.sort(interfaces);
+            int counter = 0;
+            for (int i = 0; i < interfaces.length; i++) {
+                if (parent != interfaces[i]) {
+                    if (! (interfaces[i].isPublic() ||
+                            Util.isLinkable(interfaces[i], configuration))) {
+                        continue;
+                    }
+                    if (counter == 0) {
+                        if (cd.isInterface()) {
+                            contentTree.addContent(" (");
+                            contentTree.addContent(getResource("doclet.also"));
+                            contentTree.addContent(" extends ");
+                        } else {
+                            contentTree.addContent(" (implements ");
+                        }
+                    } else {
+                        contentTree.addContent(", ");
+                    }
+                    addPreQualifiedClassLink(LinkInfoImpl.Kind.TREE,
+                            interfaces[i], contentTree);
+                    counter++;
+                }
+            }
+            if (counter > 0) {
+                contentTree.addContent(")");
+            }
+        }
+    }
+
+    /**
+     * Add information about the class kind, if it's a "class" or "interface".
+     *
+     * @param cd the class being documented
+     * @param contentTree the content tree to which the information will be added
+     */
+    protected void addPartialInfo(ClassDoc cd, Content contentTree) {
+        addPreQualifiedStrongClassLink(LinkInfoImpl.Kind.TREE, cd, contentTree);
+    }
+
+    /**
+     * Get the tree label for the navigation bar.
+     *
+     * @return a content tree for the tree label
+     */
+    protected Content getNavLinkTree() {
+        Content li = HtmlTree.LI(HtmlStyle.navBarCell1Rev, treeLabel);
+        return li;
+    }
+}