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.juneau;
018
019/**
020 * Global constants used across the Juneau framework.
021 */
022public class Constants {
023
024   /**
025    * Sentinel value to indicate that a default value is not specified.
026    * 
027    * <p>
028    * Used in annotation default values where empty string cannot distinguish between
029    * "no value specified" and "explicitly set to empty string".
030    */
031   public static final String NONE = "_NONE_";
032}