1 /*
2 * ====================================================================
3 * Licensed to the Apache Software Foundation (ASF) under one
4 * or more contributor license agreements. See the NOTICE file
5 * distributed with this work for additional information
6 * regarding copyright ownership. The ASF licenses this file
7 * to you under the Apache License, Version 2.0 (the
8 * "License"); you may not use this file except in compliance
9 * with the License. You may obtain a copy of the License at
10 *
11 * http://www.apache.org/licenses/LICENSE-2.0
12 *
13 * Unless required by applicable law or agreed to in writing,
14 * software distributed under the License is distributed on an
15 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
16 * KIND, either express or implied. See the License for the
17 * specific language governing permissions and limitations
18 * under the License.
19 * ====================================================================
20 *
21 * This software consists of voluntary contributions made by many
22 * individuals on behalf of the Apache Software Foundation. For more
23 * information on the Apache Software Foundation, please see
24 * <http://www.apache.org/>.
25 *
26 */
27
28 package org.apache.hc.core5.http;
29
30 import java.io.Serializable;
31
32 import org.apache.hc.core5.annotation.Contract;
33 import org.apache.hc.core5.annotation.Internal;
34 import org.apache.hc.core5.annotation.ThreadingBehavior;
35 import org.apache.hc.core5.util.Args;
36 import org.apache.hc.core5.util.Tokenizer;
37
38 /**
39 * Represents a protocol version. The "major.minor" numbering
40 * scheme is used to indicate versions of the protocol.
41 * <p>
42 * This class defines a protocol version as a combination of
43 * protocol name, major version number, and minor version number.
44 * Note that {@link #equals} and {@link #hashCode} are defined as
45 * final here, they cannot be overridden in derived classes.
46 * </p>
47 *
48 * @since 4.0
49 */
50 @Contract(threading = ThreadingBehavior.IMMUTABLE)
51 public class ProtocolVersion implements Serializable {
52
53 private static final long serialVersionUID = 8950662842175091068L;
54
55
56 /** Name of the protocol. */
57 private final String protocol;
58
59 /** Major version number of the protocol */
60 private final int major;
61
62 /** Minor version number of the protocol */
63 private final int minor;
64
65 /**
66 * Create a protocol version designator.
67 *
68 * @param protocol the name of the protocol, for example "HTTP"
69 * @param major the major version number of the protocol
70 * @param minor the minor version number of the protocol
71 */
72 public ProtocolVersion(final String protocol, final int major, final int minor) {
73 this.protocol = Args.notNull(protocol, "Protocol name");
74 this.major = Args.notNegative(major, "Protocol minor version");
75 this.minor = Args.notNegative(minor, "Protocol minor version");
76 }
77
78 /**
79 * Returns the name of the protocol.
80 *
81 * @return the protocol name
82 */
83 public final String getProtocol() {
84 return protocol;
85 }
86
87 /**
88 * Returns the major version number of the protocol.
89 *
90 * @return the major version number.
91 */
92 public final int getMajor() {
93 return major;
94 }
95
96 /**
97 * Returns the minor version number of the HTTP protocol.
98 *
99 * @return the minor version number.
100 */
101 public final int getMinor() {
102 return minor;
103 }
104
105
106 /**
107 * Obtains a hash code consistent with {@link #equals}.
108 *
109 * @return the hashcode of this protocol version
110 */
111 @Override
112 public final int hashCode() {
113 return this.protocol.hashCode() ^ (this.major * 100000) ^ this.minor;
114 }
115
116 /**
117 * Checks whether this instance has the same major and minor version as the arguments.
118 *
119 * @param major the major version to check.
120 * @param minor the minor version to check.
121 * @return whether this instance has the same major and minor version as the arguments.
122 * @since 5.0
123 */
124 public final boolean equals(final int major, final int minor) {
125 return this.major == major && this.minor == minor;
126 }
127
128 /**
129 * Checks equality of this protocol version with an object.
130 * The object is equal if it is a protocol version with the same
131 * protocol name, major version number, and minor version number.
132 * The specific class of the object is <i>not</i> relevant,
133 * instances of derived classes with identical attributes are
134 * equal to instances of the base class and vice versa.
135 *
136 * @param obj the object to compare with
137 *
138 * @return {@code true} if the argument is the same protocol version,
139 * {@code false} otherwise
140 */
141 @Override
142 public final boolean equals(final Object obj) {
143 if (this == obj) {
144 return true;
145 }
146 if (!(obj instanceof ProtocolVersion)) {
147 return false;
148 }
149 final ProtocolVersion that = (ProtocolVersion) obj;
150
151 return (this.protocol.equals(that.protocol) &&
152 (this.major == that.major) &&
153 (this.minor == that.minor));
154 }
155
156 /**
157 * Formats this protocol version as a string.
158 *
159 * @return a protocol version string, like "HTTP/1.1"
160 * @since 5.0
161 */
162 public String format() {
163 final StringBuilder buffer = new StringBuilder();
164 buffer.append(this.protocol);
165 buffer.append('/');
166 buffer.append(this.major);
167 buffer.append('.');
168 buffer.append(this.minor);
169 return buffer.toString();
170 }
171
172 /**
173 * Checks whether this protocol can be compared to another one.
174 * Only protocol versions with the same protocol name can be
175 * {@link #compareToVersion compared}.
176 *
177 * @param that the protocol version to consider
178 *
179 * @return {@code true} if {@link #compareToVersion compareToVersion}
180 * can be called with the argument, {@code false} otherwise
181 */
182 public boolean isComparable(final ProtocolVersion that) {
183 return (that != null) && this.protocol.equals(that.protocol);
184 }
185
186
187 /**
188 * Compares this protocol version with another one.
189 * Only protocol versions with the same protocol name can be compared.
190 * This method does <i>not</i> define a total ordering, as it would be
191 * required for {@link java.lang.Comparable}.
192 *
193 * @param that the protocol version to compare with
194 *
195 * @return a negative integer, zero, or a positive integer
196 * as this version is less than, equal to, or greater than
197 * the argument version.
198 *
199 * @throws IllegalArgumentException
200 * if the argument has a different protocol name than this object,
201 * or if the argument is {@code null}
202 */
203 public int compareToVersion(final ProtocolVersion that) {
204 Args.notNull(that, "Protocol version");
205 Args.check(this.protocol.equals(that.protocol),
206 "Versions for different protocols cannot be compared: %s %s", this, that);
207 int delta = getMajor() - that.getMajor();
208 if (delta == 0) {
209 delta = getMinor() - that.getMinor();
210 }
211 return delta;
212 }
213
214
215 /**
216 * Tests if this protocol version is greater or equal to the given one.
217 *
218 * @param version the version against which to check this version
219 *
220 * @return {@code true} if this protocol version is
221 * {@link #isComparable comparable} to the argument
222 * and {@link #compareToVersion compares} as greater or equal,
223 * {@code false} otherwise
224 */
225 public final boolean greaterEquals(final ProtocolVersion version) {
226 return isComparable(version) && (compareToVersion(version) >= 0);
227 }
228
229
230 /**
231 * Tests if this protocol version is less or equal to the given one.
232 *
233 * @param version the version against which to check this version
234 *
235 * @return {@code true} if this protocol version is
236 * {@link #isComparable comparable} to the argument
237 * and {@link #compareToVersion compares} as less or equal,
238 * {@code false} otherwise
239 */
240 public final boolean lessEquals(final ProtocolVersion version) {
241 return isComparable(version) && (compareToVersion(version) <= 0);
242 }
243
244 @Internal
245 public static ProtocolVersion parse(
246 final CharSequence buffer,
247 final Tokenizer.Cursor cursor,
248 final Tokenizer.Delimiter delimiterPredicate) throws ParseException {
249 return ProtocolVersionParser.INSTANCE.parse(buffer, cursor, delimiterPredicate);
250 }
251
252 /**
253 * @since 5.3
254 */
255 public static ProtocolVersion parse(final String s) throws ParseException {
256 if (s == null) {
257 return null;
258 }
259 final Tokenizer.Cursor cursor = new Tokenizer.Cursor(0, s.length());
260 final ProtocolVersion protocolVersion = ProtocolVersionParser.INSTANCE.parse(s, cursor, null);
261 Tokenizer.INSTANCE.skipWhiteSpace(s, cursor);
262 if (!cursor.atEnd()) {
263 throw new ParseException("Invalid protocol version; trailing content");
264 }
265 return protocolVersion;
266 }
267
268 /**
269 * Converts this protocol version to a string.
270 *
271 * @return a protocol version string, like "HTTP/1.1"
272 */
273 @Override
274 public String toString() {
275 return format();
276 }
277
278 }