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.ThreadingBehavior;
34 import org.apache.hc.core5.util.Args;
35
36 /**
37 * Represents a protocol version. The "major.minor" numbering
38 * scheme is used to indicate versions of the protocol.
39 * <p>
40 * This class defines a protocol version as a combination of
41 * protocol name, major version number, and minor version number.
42 * Note that {@link #equals} and {@link #hashCode} are defined as
43 * final here, they cannot be overridden in derived classes.
44 * </p>
45 *
46 * @since 4.0
47 */
48 @Contract(threading = ThreadingBehavior.IMMUTABLE)
49 public class ProtocolVersion implements Serializable {
50
51 private static final long serialVersionUID = 8950662842175091068L;
52
53
54 /** Name of the protocol. */
55 private final String protocol;
56
57 /** Major version number of the protocol */
58 private final int major;
59
60 /** Minor version number of the protocol */
61 private final int minor;
62
63 /**
64 * Create a protocol version designator.
65 *
66 * @param protocol the name of the protocol, for example "HTTP"
67 * @param major the major version number of the protocol
68 * @param minor the minor version number of the protocol
69 */
70 public ProtocolVersion(final String protocol, final int major, final int minor) {
71 this.protocol = Args.notNull(protocol, "Protocol name");
72 this.major = Args.notNegative(major, "Protocol minor version");
73 this.minor = Args.notNegative(minor, "Protocol minor version");
74 }
75
76 /**
77 * Returns the name of the protocol.
78 *
79 * @return the protocol name
80 */
81 public final String getProtocol() {
82 return protocol;
83 }
84
85 /**
86 * Returns the major version number of the protocol.
87 *
88 * @return the major version number.
89 */
90 public final int getMajor() {
91 return major;
92 }
93
94 /**
95 * Returns the minor version number of the HTTP protocol.
96 *
97 * @return the minor version number.
98 */
99 public final int getMinor() {
100 return minor;
101 }
102
103
104 /**
105 * Obtains a hash code consistent with {@link #equals}.
106 *
107 * @return the hashcode of this protocol version
108 */
109 @Override
110 public final int hashCode() {
111 return this.protocol.hashCode() ^ (this.major * 100000) ^ this.minor;
112 }
113
114 /**
115 * Checks whether this instance has the same major and minor version as the arguments.
116 *
117 * @param major the major version to check.
118 * @param minor the minor version to check.
119 * @return whether this instance has the same major and minor version as the arguments.
120 * @since 5.0
121 */
122 public final boolean equals(final int major, final int minor) {
123 return this.major == major && this.minor == minor;
124 }
125
126 /**
127 * Checks equality of this protocol version with an object.
128 * The object is equal if it is a protocol version with the same
129 * protocol name, major version number, and minor version number.
130 * The specific class of the object is <i>not</i> relevant,
131 * instances of derived classes with identical attributes are
132 * equal to instances of the base class and vice versa.
133 *
134 * @param obj the object to compare with
135 *
136 * @return {@code true} if the argument is the same protocol version,
137 * {@code false} otherwise
138 */
139 @Override
140 public final boolean equals(final Object obj) {
141 if (this == obj) {
142 return true;
143 }
144 if (!(obj instanceof ProtocolVersion)) {
145 return false;
146 }
147 final ProtocolVersion./../../org/apache/hc/core5/http/ProtocolVersion.html#ProtocolVersion">ProtocolVersion that = (ProtocolVersion) obj;
148
149 return (this.protocol.equals(that.protocol) &&
150 (this.major == that.major) &&
151 (this.minor == that.minor));
152 }
153
154 /**
155 * Formats this protocol version as a string.
156 *
157 * @return a protocol version string, like "HTTP/1.1"
158 * @since 5.0
159 */
160 public String format() {
161 final StringBuilder buffer = new StringBuilder();
162 buffer.append(this.protocol);
163 buffer.append('/');
164 buffer.append(this.major);
165 buffer.append('.');
166 buffer.append(this.minor);
167 return buffer.toString();
168 }
169
170 /**
171 * Checks whether this protocol can be compared to another one.
172 * Only protocol versions with the same protocol name can be
173 * {@link #compareToVersion compared}.
174 *
175 * @param that the protocol version to consider
176 *
177 * @return {@code true} if {@link #compareToVersion compareToVersion}
178 * can be called with the argument, {@code false} otherwise
179 */
180 public boolean isComparable(final ProtocolVersion that) {
181 return (that != null) && this.protocol.equals(that.protocol);
182 }
183
184
185 /**
186 * Compares this protocol version with another one.
187 * Only protocol versions with the same protocol name can be compared.
188 * This method does <i>not</i> define a total ordering, as it would be
189 * required for {@link java.lang.Comparable}.
190 *
191 * @param that the protocol version to compare with
192 *
193 * @return a negative integer, zero, or a positive integer
194 * as this version is less than, equal to, or greater than
195 * the argument version.
196 *
197 * @throws IllegalArgumentException
198 * if the argument has a different protocol name than this object,
199 * or if the argument is {@code null}
200 */
201 public int compareToVersion(final ProtocolVersion that) {
202 Args.notNull(that, "Protocol version");
203 Args.check(this.protocol.equals(that.protocol),
204 "Versions for different protocols cannot be compared: %s %s", this, that);
205 int delta = getMajor() - that.getMajor();
206 if (delta == 0) {
207 delta = getMinor() - that.getMinor();
208 }
209 return delta;
210 }
211
212
213 /**
214 * Tests if this protocol version is greater or equal to the given one.
215 *
216 * @param version the version against which to check this version
217 *
218 * @return {@code true} if this protocol version is
219 * {@link #isComparable comparable} to the argument
220 * and {@link #compareToVersion compares} as greater or equal,
221 * {@code false} otherwise
222 */
223 public final boolean greaterEquals(final ProtocolVersion version) {
224 return isComparable(version) && (compareToVersion(version) >= 0);
225 }
226
227
228 /**
229 * Tests if this protocol version is less or equal to the given one.
230 *
231 * @param version the version against which to check this version
232 *
233 * @return {@code true} if this protocol version is
234 * {@link #isComparable comparable} to the argument
235 * and {@link #compareToVersion compares} as less or equal,
236 * {@code false} otherwise
237 */
238 public final boolean lessEquals(final ProtocolVersion version) {
239 return isComparable(version) && (compareToVersion(version) <= 0);
240 }
241
242
243 /**
244 * Converts this protocol version to a string.
245 *
246 * @return a protocol version string, like "HTTP/1.1"
247 */
248 @Override
249 public String toString() {
250 return format();
251 }
252
253 }