com.google.common.net.HostAndPort Maven / Gradle / Ivy
/*
* Copyright (C) 2011 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
* in compliance with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software distributed under the License
* is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
* or implied. See the License for the specific language governing permissions and limitations under
* the License.
*/
package com.google.common.net;
import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkNotNull;
import static com.google.common.base.Preconditions.checkState;
import com.google.common.annotations.GwtCompatible;
import com.google.common.base.CharMatcher;
import com.google.common.base.Objects;
import com.google.common.base.Strings;
import com.google.errorprone.annotations.CanIgnoreReturnValue;
import com.google.errorprone.annotations.Immutable;
import java.io.Serializable;
import javax.annotation.CheckForNull;
/**
* An immutable representation of a host and port.
*
* Example usage:
*
*
* HostAndPort hp = HostAndPort.fromString("[2001:db8::1]")
* .withDefaultPort(80)
* .requireBracketsForIPv6();
* hp.getHost(); // returns "2001:db8::1"
* hp.getPort(); // returns 80
* hp.toString(); // returns "[2001:db8::1]:80"
*
*
* Here are some examples of recognized formats:
*
*
* - example.com
*
- example.com:80
*
- 192.0.2.1
*
- 192.0.2.1:80
*
- [2001:db8::1] - {@link #getHost()} omits brackets
*
- [2001:db8::1]:80 - {@link #getHost()} omits brackets
*
- 2001:db8::1 - Use {@link #requireBracketsForIPv6()} to prohibit this
*
*
* Note that this is not an exhaustive list, because these methods are only concerned with
* brackets, colons, and port numbers. Full validation of the host field (if desired) is the
* caller's responsibility.
*
* @author Paul Marks
* @since 10.0
*/
@Immutable
@GwtCompatible
@ElementTypesAreNonnullByDefault
public final class HostAndPort implements Serializable {
/** Magic value indicating the absence of a port number. */
private static final int NO_PORT = -1;
/** Hostname, IPv4/IPv6 literal, or unvalidated nonsense. */
private final String host;
/** Validated port number in the range [0..65535], or NO_PORT */
private final int port;
/** True if the parsed host has colons, but no surrounding brackets. */
private final boolean hasBracketlessColons;
private HostAndPort(String host, int port, boolean hasBracketlessColons) {
this.host = host;
this.port = port;
this.hasBracketlessColons = hasBracketlessColons;
}
/**
* Returns the portion of this {@code HostAndPort} instance that should represent the hostname or
* IPv4/IPv6 literal.
*
*
A successful parse does not imply any degree of sanity in this field. For additional
* validation, see the {@link HostSpecifier} class.
*
* @since 20.0 (since 10.0 as {@code getHostText})
*/
public String getHost() {
return host;
}
/** Return true if this instance has a defined port. */
public boolean hasPort() {
return port >= 0;
}
/**
* Get the current port number, failing if no port is defined.
*
* @return a validated port number, in the range [0..65535]
* @throws IllegalStateException if no port is defined. You can use {@link #withDefaultPort(int)}
* to prevent this from occurring.
*/
public int getPort() {
checkState(hasPort());
return port;
}
/** Returns the current port number, with a default if no port is defined. */
public int getPortOrDefault(int defaultPort) {
return hasPort() ? port : defaultPort;
}
/**
* Build a HostAndPort instance from separate host and port values.
*
*
Note: Non-bracketed IPv6 literals are allowed. Use {@link #requireBracketsForIPv6()} to
* prohibit these.
*
* @param host the host string to parse. Must not contain a port number.
* @param port a port number from [0..65535]
* @return if parsing was successful, a populated HostAndPort object.
* @throws IllegalArgumentException if {@code host} contains a port number, or {@code port} is out
* of range.
*/
public static HostAndPort fromParts(String host, int port) {
checkArgument(isValidPort(port), "Port out of range: %s", port);
HostAndPort parsedHost = fromString(host);
checkArgument(!parsedHost.hasPort(), "Host has a port: %s", host);
return new HostAndPort(parsedHost.host, port, parsedHost.hasBracketlessColons);
}
/**
* Build a HostAndPort instance from a host only.
*
*
Note: Non-bracketed IPv6 literals are allowed. Use {@link #requireBracketsForIPv6()} to
* prohibit these.
*
* @param host the host-only string to parse. Must not contain a port number.
* @return if parsing was successful, a populated HostAndPort object.
* @throws IllegalArgumentException if {@code host} contains a port number.
* @since 17.0
*/
public static HostAndPort fromHost(String host) {
HostAndPort parsedHost = fromString(host);
checkArgument(!parsedHost.hasPort(), "Host has a port: %s", host);
return parsedHost;
}
/**
* Split a freeform string into a host and port, without strict validation.
*
*
Note that the host-only formats will leave the port field undefined. You can use {@link
* #withDefaultPort(int)} to patch in a default value.
*
* @param hostPortString the input string to parse.
* @return if parsing was successful, a populated HostAndPort object.
* @throws IllegalArgumentException if nothing meaningful could be parsed.
*/
@CanIgnoreReturnValue // TODO(b/219820829): consider removing
public static HostAndPort fromString(String hostPortString) {
checkNotNull(hostPortString);
String host;
String portString = null;
boolean hasBracketlessColons = false;
if (hostPortString.startsWith("[")) {
String[] hostAndPort = getHostAndPortFromBracketedHost(hostPortString);
host = hostAndPort[0];
portString = hostAndPort[1];
} else {
int colonPos = hostPortString.indexOf(':');
if (colonPos >= 0 && hostPortString.indexOf(':', colonPos + 1) == -1) {
// Exactly 1 colon. Split into host:port.
host = hostPortString.substring(0, colonPos);
portString = hostPortString.substring(colonPos + 1);
} else {
// 0 or 2+ colons. Bare hostname or IPv6 literal.
host = hostPortString;
hasBracketlessColons = (colonPos >= 0);
}
}
int port = NO_PORT;
if (!Strings.isNullOrEmpty(portString)) {
// Try to parse the whole port string as a number.
// JDK7 accepts leading plus signs. We don't want to.
checkArgument(
!portString.startsWith("+") && CharMatcher.ascii().matchesAllOf(portString),
"Unparseable port number: %s",
hostPortString);
try {
port = Integer.parseInt(portString);
} catch (NumberFormatException e) {
throw new IllegalArgumentException("Unparseable port number: " + hostPortString);
}
checkArgument(isValidPort(port), "Port number out of range: %s", hostPortString);
}
return new HostAndPort(host, port, hasBracketlessColons);
}
/**
* Parses a bracketed host-port string, throwing IllegalArgumentException if parsing fails.
*
* @param hostPortString the full bracketed host-port specification. Port might not be specified.
* @return an array with 2 strings: host and port, in that order.
* @throws IllegalArgumentException if parsing the bracketed host-port string fails.
*/
private static String[] getHostAndPortFromBracketedHost(String hostPortString) {
checkArgument(
hostPortString.charAt(0) == '[',
"Bracketed host-port string must start with a bracket: %s",
hostPortString);
int colonIndex = hostPortString.indexOf(':');
int closeBracketIndex = hostPortString.lastIndexOf(']');
checkArgument(
colonIndex > -1 && closeBracketIndex > colonIndex,
"Invalid bracketed host/port: %s",
hostPortString);
String host = hostPortString.substring(1, closeBracketIndex);
if (closeBracketIndex + 1 == hostPortString.length()) {
return new String[] {host, ""};
} else {
checkArgument(
hostPortString.charAt(closeBracketIndex + 1) == ':',
"Only a colon may follow a close bracket: %s",
hostPortString);
for (int i = closeBracketIndex + 2; i < hostPortString.length(); ++i) {
checkArgument(
Character.isDigit(hostPortString.charAt(i)),
"Port must be numeric: %s",
hostPortString);
}
return new String[] {host, hostPortString.substring(closeBracketIndex + 2)};
}
}
/**
* Provide a default port if the parsed string contained only a host.
*
*
You can chain this after {@link #fromString(String)} to include a port in case the port was
* omitted from the input string. If a port was already provided, then this method is a no-op.
*
* @param defaultPort a port number, from [0..65535]
* @return a HostAndPort instance, guaranteed to have a defined port.
*/
public HostAndPort withDefaultPort(int defaultPort) {
checkArgument(isValidPort(defaultPort));
if (hasPort()) {
return this;
}
return new HostAndPort(host, defaultPort, hasBracketlessColons);
}
/**
* Generate an error if the host might be a non-bracketed IPv6 literal.
*
*
URI formatting requires that IPv6 literals be surrounded by brackets, like "[2001:db8::1]".
* Chain this call after {@link #fromString(String)} to increase the strictness of the parser, and
* disallow IPv6 literals that don't contain these brackets.
*
*
Note that this parser identifies IPv6 literals solely based on the presence of a colon. To
* perform actual validation of IP addresses, see the {@link InetAddresses#forString(String)}
* method.
*
* @return {@code this}, to enable chaining of calls.
* @throws IllegalArgumentException if bracketless IPv6 is detected.
*/
@CanIgnoreReturnValue
public HostAndPort requireBracketsForIPv6() {
checkArgument(!hasBracketlessColons, "Possible bracketless IPv6 literal: %s", host);
return this;
}
@Override
public boolean equals(@CheckForNull Object other) {
if (this == other) {
return true;
}
if (other instanceof HostAndPort) {
HostAndPort that = (HostAndPort) other;
return Objects.equal(this.host, that.host) && this.port == that.port;
}
return false;
}
@Override
public int hashCode() {
return Objects.hashCode(host, port);
}
/** Rebuild the host:port string, including brackets if necessary. */
@Override
public String toString() {
// "[]:12345" requires 8 extra bytes.
StringBuilder builder = new StringBuilder(host.length() + 8);
if (host.indexOf(':') >= 0) {
builder.append('[').append(host).append(']');
} else {
builder.append(host);
}
if (hasPort()) {
builder.append(':').append(port);
}
return builder.toString();
}
/** Return true for valid port numbers. */
private static boolean isValidPort(int port) {
return port >= 0 && port <= 65535;
}
private static final long serialVersionUID = 0;
}