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1   /*
2    * Copyright (c) 2012, Oracle and/or its affiliates. All rights reserved.
3    * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4    *
5    * This code is free software; you can redistribute it and/or modify it
6    * under the terms of the GNU General Public License version 2 only, as
7    * published by the Free Software Foundation.  Oracle designates this
8    * particular file as subject to the "Classpath" exception as provided
9    * by Oracle in the LICENSE file that accompanied this code.
10   *
11   * This code is distributed in the hope that it will be useful, but WITHOUT
12   * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13   * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14   * version 2 for more details (a copy is included in the LICENSE file that
15   * accompanied this code).
16   *
17   * You should have received a copy of the GNU General Public License version
18   * 2 along with this work; if not, write to the Free Software Foundation,
19   * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20   *
21   * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22   * or visit www.oracle.com if you need additional information or have any
23   * questions.
24   */
25  
26  package com.sun.tools.doclets.internal.toolkit.util;
27  
28  /**
29   * Abstraction for simple relative URIs, consisting of a path,
30   * an optional query, and an optional fragment. DocLink objects can
31   * be created by the constructors below or from a DocPath using the
32   * convenience methods, {@link DocPath#fragment fragment} and
33   * {@link DocPath#query query}.
34   *
35   *  <p><b>This is NOT part of any supported API.
36   *  If you write code that depends on this, you do so at your own risk.
37   *  This code and its internal interfaces are subject to change or
38   *  deletion without notice.</b>
39   *
40   */
41  public class DocLink {
42      final String path;
43      final String query;
44      final String fragment;
45  
46      /** Create a DocLink representing the URI {@code #fragment}. */
47      public static DocLink fragment(String fragment) {
48          return new DocLink((String) null, (String) null, fragment);
49      }
50  
51      /** Create a DocLink representing the URI {@code path}. */
52      public DocLink(DocPath path) {
53          this(path.getPath(), null, null);
54      }
55  
56      /**
57       * Create a DocLink representing the URI {@code path?query#fragment}.
58       * query and fragment may be null.
59       */
60      public DocLink(DocPath path, String query, String fragment) {
61          this(path.getPath(), query, fragment);
62      }
63  
64      /**
65       * Create a DocLink representing the URI {@code path?query#fragment}.
66       * Any of the component parts may be null.
67       */
68      public DocLink(String path, String query, String fragment) {
69          this.path = path;
70          this.query = query;
71          this.fragment = fragment;
72      }
73  
74      /**
75       * Return the link in the form "path?query#fragment", omitting any empty
76       * components.
77       */
78      @Override
79      public String toString() {
80          // common fast path
81          if (path != null && isEmpty(query) && isEmpty(fragment))
82              return path;
83  
84          StringBuilder sb = new StringBuilder();
85          if (path != null)
86              sb.append(path);
87          if (!isEmpty(query))
88              sb.append("?").append(query);
89          if (!isEmpty(fragment))
90              sb.append("#").append(fragment);
91          return sb.toString();
92      }
93  
94      private static boolean isEmpty(String s) {
95          return (s == null) || s.isEmpty();
96      }
97  }