001 /*
002 * Copyright (C) 2011 The Guava Authors
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 * http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016
017 package com.google.common.net;
018
019 import static com.google.common.base.Preconditions.checkArgument;
020 import static com.google.common.base.Preconditions.checkNotNull;
021 import static com.google.common.base.Preconditions.checkState;
022
023 import com.google.common.annotations.Beta;
024 import com.google.common.base.Objects;
025
026 import java.io.Serializable;
027 import java.util.regex.Matcher;
028 import java.util.regex.Pattern;
029
030 import javax.annotation.concurrent.Immutable;
031
032 /**
033 * An immutable representation of a host and port.
034 *
035 * <p>Example usage:
036 * <pre>
037 * HostAndPort hp = HostAndPort.fromString("[2001:db8::1]")
038 * .withDefaultPort(80)
039 * .requireBracketsForIPv6();
040 * hp.getHostText(); // returns "2001:db8::1"
041 * hp.getPort(); // returns 80
042 * hp.toString(); // returns "[2001:db8::1]:80"
043 * </pre>
044 *
045 * <p>Here are some examples of recognized formats:
046 * <ul>
047 * <li>example.com
048 * <li>example.com:80
049 * <li>192.0.2.1
050 * <li>192.0.2.1:80
051 * <li>[2001:db8::1] - {@link #getHostText()} omits brackets
052 * <li>[2001:db8::1]:80 - {@link #getHostText()} omits brackets
053 * <li>2001:db8::1 - Use {@link #requireBracketsForIPv6()} to prohibit this
054 * </ul>
055 *
056 * <p>Note that this is not an exhaustive list, because these methods are only
057 * concerned with brackets, colons, and port numbers. Full validation of the
058 * host field (if desired) is the caller's responsibility.
059 *
060 * @author Paul Marks
061 * @since 10.0
062 */
063 @Beta @Immutable
064 public final class HostAndPort implements Serializable {
065 /** Magic value indicating the absence of a port number. */
066 private static final int NO_PORT = -1;
067
068 /** Hostname, IPv4/IPv6 literal, or unvalidated nonsense. */
069 private final String host;
070
071 /** Validated port number in the range [0..65535], or NO_PORT */
072 private final int port;
073
074 /** True if the parsed host has colons, but no surrounding brackets. */
075 private final boolean hasBracketlessColons;
076
077 private HostAndPort(String host, int port, boolean hasBracketlessColons) {
078 this.host = host;
079 this.port = port;
080 this.hasBracketlessColons = hasBracketlessColons;
081 }
082
083 /**
084 * Returns the portion of this {@code HostAndPort} instance that should
085 * represent the hostname or IPv4/IPv6 literal.
086 *
087 * A successful parse does not imply any degree of sanity in this field.
088 * For additional validation, see the {@link HostSpecifier} class.
089 */
090 public String getHostText() {
091 return host;
092 }
093
094 /** Return true if this instance has a defined port. */
095 public boolean hasPort() {
096 return port >= 0;
097 }
098
099 /**
100 * Get the current port number, failing if no port is defined.
101 *
102 * @return a validated port number, in the range [0..65535]
103 * @throws IllegalStateException if no port is defined. You can use
104 * {@link #withDefaultPort(int)} to prevent this from occurring.
105 */
106 public int getPort() {
107 checkState(hasPort());
108 return port;
109 }
110
111 /**
112 * Returns the current port number, with a default if no port is defined.
113 */
114 public int getPortOrDefault(int defaultPort) {
115 return hasPort() ? port : defaultPort;
116 }
117
118 /**
119 * Build a HostAndPort instance from separate host and port values.
120 *
121 * <p>Note: Non-bracketed IPv6 literals are allowed.
122 * Use {@link #requireBracketsForIPv6()} to prohibit these.
123 *
124 * @param host the host string to parse. Must not contain a port number.
125 * @param port a port number from [0..65535]
126 * @return if parsing was successful, a populated HostAndPort object.
127 * @throws IllegalArgumentException if {@code host} contains a port number,
128 * or {@code port} is out of range.
129 */
130 public static HostAndPort fromParts(String host, int port) {
131 checkArgument(isValidPort(port));
132 HostAndPort parsedHost = fromString(host);
133 checkArgument(!parsedHost.hasPort());
134 return new HostAndPort(parsedHost.host, port, parsedHost.hasBracketlessColons);
135 }
136
137 private static final Pattern BRACKET_PATTERN = Pattern.compile("^\\[(.*:.*)\\](?::(\\d*))?$");
138
139 /**
140 * Split a freeform string into a host and port, without strict validation.
141 *
142 * Note that the host-only formats will leave the port field undefined. You
143 * can use {@link #withDefaultPort(int)} to patch in a default value.
144 *
145 * @param hostPortString the input string to parse.
146 * @return if parsing was successful, a populated HostAndPort object.
147 * @throws IllegalArgumentException if nothing meaningful could be parsed.
148 */
149 public static HostAndPort fromString(String hostPortString) {
150 checkNotNull(hostPortString);
151 String host;
152 String portString = null;
153 boolean hasBracketlessColons = false;
154
155 if (hostPortString.startsWith("[")) {
156 // Parse a bracketed host, typically an IPv6 literal.
157 Matcher matcher = BRACKET_PATTERN.matcher(hostPortString);
158 checkArgument(matcher.matches(), "Invalid bracketed host/port: %s", hostPortString);
159 host = matcher.group(1);
160 portString = matcher.group(2); // could be null
161 } else {
162 int colonPos = hostPortString.indexOf(':');
163 if (colonPos >= 0 && hostPortString.indexOf(':', colonPos + 1) == -1) {
164 // Exactly 1 colon. Split into host:port.
165 host = hostPortString.substring(0, colonPos);
166 portString = hostPortString.substring(colonPos + 1);
167 } else {
168 // 0 or 2+ colons. Bare hostname or IPv6 literal.
169 host = hostPortString;
170 hasBracketlessColons = (colonPos >= 0);
171 }
172 }
173
174 int port = NO_PORT;
175 if (portString != null) {
176 // Try to parse the whole port string as a number.
177 // JDK7 accepts leading plus signs. We don't want to.
178 checkArgument(!portString.startsWith("+"), "Unparseable port number: %s", hostPortString);
179 try {
180 port = Integer.parseInt(portString);
181 } catch (NumberFormatException e) {
182 throw new IllegalArgumentException("Unparseable port number: " + hostPortString);
183 }
184 checkArgument(isValidPort(port), "Port number out of range: %s", hostPortString);
185 }
186
187 return new HostAndPort(host, port, hasBracketlessColons);
188 }
189
190 /**
191 * Provide a default port if the parsed string contained only a host.
192 *
193 * You can chain this after {@link #fromString(String)} to include a port in
194 * case the port was omitted from the input string. If a port was already
195 * provided, then this method is a no-op.
196 *
197 * @param defaultPort a port number, from [0..65535]
198 * @return a HostAndPort instance, guaranteed to have a defined port.
199 */
200 public HostAndPort withDefaultPort(int defaultPort) {
201 checkArgument(isValidPort(defaultPort));
202 if (hasPort() || port == defaultPort) {
203 return this;
204 }
205 return new HostAndPort(host, defaultPort, hasBracketlessColons);
206 }
207
208 /**
209 * Generate an error if the host might be a non-bracketed IPv6 literal.
210 *
211 * <p>URI formatting requires that IPv6 literals be surrounded by brackets,
212 * like "[2001:db8::1]". Chain this call after {@link #fromString(String)}
213 * to increase the strictness of the parser, and disallow IPv6 literals
214 * that don't contain these brackets.
215 *
216 * <p>Note that this parser identifies IPv6 literals solely based on the
217 * presence of a colon. To perform actual validation of IP addresses, see
218 * the {@link InetAddresses#forString(String)} method.
219 *
220 * @return {@code this}, to enable chaining of calls.
221 * @throws IllegalArgumentException if bracketless IPv6 is detected.
222 */
223 public HostAndPort requireBracketsForIPv6() {
224 checkArgument(!hasBracketlessColons, "Possible bracketless IPv6 literal: %s", host);
225 return this;
226 }
227
228 @Override
229 public boolean equals(Object other) {
230 if (this == other) {
231 return true;
232 }
233 if (other instanceof HostAndPort) {
234 HostAndPort that = (HostAndPort) other;
235 return Objects.equal(this.host, that.host)
236 && this.port == that.port
237 && this.hasBracketlessColons == that.hasBracketlessColons;
238 }
239 return false;
240 }
241
242 @Override
243 public int hashCode() {
244 return Objects.hashCode(host, port, hasBracketlessColons);
245 }
246
247 /** Rebuild the host:port string, including brackets if necessary. */
248 @Override
249 public String toString() {
250 StringBuilder builder = new StringBuilder(host.length() + 7);
251 if (host.indexOf(':') >= 0) {
252 builder.append('[').append(host).append(']');
253 } else {
254 builder.append(host);
255 }
256 if (hasPort()) {
257 builder.append(':').append(port);
258 }
259 return builder.toString();
260 }
261
262 /** Return true for valid port numbers. */
263 private static boolean isValidPort(int port) {
264 return port >= 0 && port <= 65535;
265 }
266
267 private static final long serialVersionUID = 0;
268 }