google.registry.tldconfig.idn.IdnLabelValidator.java Source code

Introduction

Here is the source code for google.registry.tldconfig.idn.IdnLabelValidator.java

Source

// Copyright 2016 The Nomulus 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.tldconfig.idn;

import static google.registry.tldconfig.idn.IdnTableEnum.EXTENDED_LATIN;
import static google.registry.tldconfig.idn.IdnTableEnum.JA;

import com.google.common.base.Optional;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableMap;
import google.registry.util.Idn;
import google.registry.util.NonFinalForTesting;

/** Validates whether a given IDN label can be provisioned for a particular TLD. */
public final class IdnLabelValidator {

    /** Most TLDs will use this generic list of IDN tables. */
    private static final ImmutableList<IdnTableEnum> DEFAULT_IDN_TABLES = ImmutableList.of(EXTENDED_LATIN, JA);

    /** Some TLDs have their own IDN tables, configured here. */
    @NonFinalForTesting
    private static ImmutableMap<String, ImmutableList<IdnTableEnum>> idnTableListsPerTld = ImmutableMap
            .of("xn--q9jyb4c", ImmutableList.of(EXTENDED_LATIN, JA));

    /**
     * Returns name of first matching {@link IdnTable} if domain label is valid for the given TLD.
     *
     * <p>A label is valid if it is considered valid by at least one configured IDN table for that
     * TLD. If no match is found, an absent value is returned.
     */
    public static Optional<String> findValidIdnTableForTld(String label, String tld) {
        String unicodeString = Idn.toUnicode(label);
        for (IdnTableEnum idnTable : Optional.fromNullable(idnTableListsPerTld.get(tld)).or(DEFAULT_IDN_TABLES)) {
            if (idnTable.getTable().isValidLabel(unicodeString)) {
                return Optional.of(idnTable.getTable().getName());
            }
        }
        return Optional.absent();
    }

    private IdnLabelValidator() {
    }
}