google-nomulus/java/google/registry/util/DomainNameUtils.java
mcilwain a2d2764115 Change second-level domain name to fully-qualified domain name
Second-level domain name isn't accurate because we support multi-part
TLDs, so standardize on the "fullyQualifiedDomainName" name that is
used throughout the code base.
-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=122693009
2016-05-27 12:42:33 -04:00

79 lines
3.4 KiB
Java

// Copyright 2016 The Domain Registry Authors. All Rights Reserved.
//
// 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 google.registry.util;
import static com.google.common.base.Preconditions.checkArgument;
import static google.registry.util.PreconditionsUtils.checkArgumentNotNull;
import com.google.common.base.Ascii;
import com.google.common.base.Strings;
import com.google.common.net.InternetDomainName;
/** Utility methods related to domain names. */
public final class DomainNameUtils {
/** Prefix for unicode domain name parts. */
public static final String ACE_PREFIX = "xn--";
public static final String ACE_PREFIX_REGEX = "^xn--";
/** Checks whether "name" is a strict subdomain of "potentialParent". */
public static boolean isUnder(InternetDomainName name, InternetDomainName potentialParent) {
int numNameParts = name.parts().size();
int numParentParts = potentialParent.parts().size();
return numNameParts > numParentParts
&& name.parts().subList(numNameParts - numParentParts, numNameParts)
.equals(potentialParent.parts());
}
/** Canonicalizes a domain name by lowercasing and converting unicode to punycode. */
public static String canonicalizeDomainName(String label) {
return Idn.toASCII(Ascii.toLowerCase(label));
}
/**
* Returns the canonicalized TLD part of a valid domain name by stripping off the leftmost part.
*
* <p>This function is compatible with multi-part tlds, e.g. {@code co.uk}. This function will
* also work on domains for which the registry is not authoritative. If you are certain that the
* input will be under a TLD this registry controls, then it is preferable to use
* {@link google.registry.model.registry.Registries#findTldForName(InternetDomainName)
* Registries#findTldForName}, which will work on hostnames in addition to domains.
*
* @param fullyQualifiedDomainName must be a puny-coded domain name (not a subdomain or Unicode)
* @throws IllegalArgumentException if there is no TLD
*/
public static String getTldFromDomainName(String fullyQualifiedDomainName) {
checkArgument(
!Strings.isNullOrEmpty(fullyQualifiedDomainName),
"fullyQualifiedDomainName cannot be null or empty");
return getTldFromDomainName(InternetDomainName.from(fullyQualifiedDomainName));
}
/**
* Returns the canonicalized TLD part of a valid domain name by stripping off the leftmost part.
*
* <p>This function is compatible with multi-part TLDs and must not be called with subdomains.
*
* @throws IllegalArgumentException if there is no TLD
*/
public static String getTldFromDomainName(InternetDomainName fullyQualifiedDomainName) {
checkArgumentNotNull(fullyQualifiedDomainName);
checkArgument(
fullyQualifiedDomainName.hasParent(), "fullyQualifiedDomainName does not have a TLD");
return fullyQualifiedDomainName.parent().toString();
}
private DomainNameUtils() {}
}