001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements. See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache license, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License. You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the license for the specific language governing permissions and
015 * limitations under the license.
016 */
017package org.apache.logging.log4j.core.config.plugins.validation.constraints;
018
019import org.apache.logging.log4j.core.config.plugins.validation.Constraint;
020import org.apache.logging.log4j.core.config.plugins.validation.validators.ValidHostValidator;
021
022import java.lang.annotation.*;
023import java.net.InetAddress;
024
025/**
026 * Indicates that a plugin attribute must be a valid host. This relies on the same validation rules as
027 * {@link InetAddress#getByName(String)}.
028 *
029 * @since 2.8
030 */
031@Documented
032@Retention(RetentionPolicy.RUNTIME)
033@Target({ElementType.FIELD, ElementType.PARAMETER})
034@Constraint(ValidHostValidator.class)
035public @interface ValidHost {
036
037    /**
038     * The message to be logged if this constraint is violated. This should normally be overridden.
039     */
040    String message() default "The hostname is invalid";
041}