1 /*
2 * Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved.
3 * @LastModified: Oct 2017
4 */
5 /*
6 * Licensed to the Apache Software Foundation (ASF) under one or more
7 * contributor license agreements. See the NOTICE file distributed with
8 * this work for additional information regarding copyright ownership.
9 * The ASF licenses this file to You under the Apache License, Version 2.0
10 * (the "License"); you may not use this file except in compliance with
11 * the License. You may obtain a copy of the License at
12 *
13 * http://www.apache.org/licenses/LICENSE-2.0
14 *
15 * Unless required by applicable law or agreed to in writing, software
16 * distributed under the License is distributed on an "AS IS" BASIS,
17 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
18 * See the License for the specific language governing permissions and
19 * limitations under the License.
20 */
21
22 package com.sun.org.apache.xerces.internal.dom;
23
24 import java.util.ArrayList;
25 import java.util.List;
26 import java.util.StringTokenizer;
27 import org.w3c.dom.DOMImplementation;
28 import org.w3c.dom.DOMImplementationList;
29 import org.w3c.dom.DOMImplementationSource;
30
31 /**
32 * Supply one the right implementation, based upon requested features. Each
33 * implemented <code>DOMImplementationSource</code> object is listed in the
34 * binding-specific list of available sources so that its
35 * <code>DOMImplementation</code> objects are made available.
36 *
37 * <p>See also the
38 * <a href='http://www.w3.org/TR/2004/REC-DOM-Level-3-Core-20040407/core.html#DOMImplementationSource'>
39 * Document Object Model (DOM) Level 3 Core Specification</a>.
40 *
41 * @xerces.internal
42 *
43 */
44 public class DOMImplementationSourceImpl
45 implements DOMImplementationSource {
46
47 /**
48 * A method to request a DOM implementation.
49 * @param features A string that specifies which features are required.
50 * This is a space separated list in which each feature is specified
51 * by its name optionally followed by a space and a version number.
52 * This is something like: "XML 1.0 Traversal Events 2.0"
53 * @return An implementation that has the desired features, or
54 * <code>null</code> if this source has none.
55 */
56 public DOMImplementation getDOMImplementation(String features) {
57 // first check whether the CoreDOMImplementation would do
58 DOMImplementation impl =
59 CoreDOMImplementationImpl.getDOMImplementation();
60 if (testImpl(impl, features)) {
61 return impl;
62 }
63 // if not try the DOMImplementation
64 impl = DOMImplementationImpl.getDOMImplementation();
65 if (testImpl(impl, features)) {
66 return impl;
67 }
68
69 return null;
70 }
71
72 /**
73 * A method to request a list of DOM implementations that support the
74 * specified features and versions, as specified in .
75 * @param features A string that specifies which features and versions
76 * are required. This is a space separated list in which each feature
77 * is specified by its name optionally followed by a space and a
78 * version number. This is something like: "XML 3.0 Traversal +Events
79 * 2.0"
80 * @return A list of DOM implementations that support the desired
81 * features.
82 */
83 public DOMImplementationList getDOMImplementationList(String features) {
84 // first check whether the CoreDOMImplementation would do
85 DOMImplementation impl = CoreDOMImplementationImpl.getDOMImplementation();
86 final List<DOMImplementation> implementations = new ArrayList<>();
87 if (testImpl(impl, features)) {
88 implementations.add(impl);
89 }
90 impl = DOMImplementationImpl.getDOMImplementation();
91 if (testImpl(impl, features)) {
92 implementations.add(impl);
93 }
94
95 return new DOMImplementationListImpl(implementations);
96 }
97
98 boolean testImpl(DOMImplementation impl, String features) {
99
100 StringTokenizer st = new StringTokenizer(features);
101 String feature = null;
102 String version = null;
103
104 if (st.hasMoreTokens()) {
105 feature = st.nextToken();
106 }
107 while (feature != null) {
108 boolean isVersion = false;
109 if (st.hasMoreTokens()) {
110 char c;
111 version = st.nextToken();
112 c = version.charAt(0);
113 switch (c) {
114 case '0': case '1': case '2': case '3': case '4':
115 case '5': case '6': case '7': case '8': case '9':
116 isVersion = true;
117 }
118 } else {
119 version = null;
120 }
121 if (isVersion) {
122 if (!impl.hasFeature(feature, version)) {
123 return false;
124 }
125 if (st.hasMoreTokens()) {
126 feature = st.nextToken();
127 } else {
128 feature = null;
129 }
130 } else {
131 if (!impl.hasFeature(feature, null)) {
132 return false;
133 }
134 feature = version;
135 }
136 }
137 return true;
138 }
139 }