001/* 002 * Copyright 2012-2017 the original author or authors. 003 * 004 * Licensed under the Apache License, Version 2.0 (the "License"); 005 * you may not use this file except in compliance with the License. 006 * You may obtain a copy of the License at 007 * 008 * http://www.apache.org/licenses/LICENSE-2.0 009 * 010 * Unless required by applicable law or agreed to in writing, software 011 * distributed under the License is distributed on an "AS IS" BASIS, 012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 013 * See the License for the specific language governing permissions and 014 * limitations under the License. 015 */ 016 017package org.springframework.boot.context.properties.source; 018 019import java.util.function.Predicate; 020 021import org.springframework.util.Assert; 022 023/** 024 * The state of content from a {@link ConfigurationPropertySource}. 025 * 026 * @author Phillip Webb 027 * @since 2.0.0 028 */ 029public enum ConfigurationPropertyState { 030 031 /** 032 * The {@link ConfigurationPropertySource} has at least one matching 033 * {@link ConfigurationProperty}. 034 */ 035 PRESENT, 036 037 /** 038 * The {@link ConfigurationPropertySource} has no matching 039 * {@link ConfigurationProperty ConfigurationProperties}. 040 */ 041 ABSENT, 042 043 /** 044 * It's not possible to determine if {@link ConfigurationPropertySource} has matching 045 * {@link ConfigurationProperty ConfigurationProperties} or not. 046 */ 047 UNKNOWN; 048 049 /** 050 * Search the given iterable using a predicate to determine if content is 051 * {@link #PRESENT} or {@link #ABSENT}. 052 * @param <T> the data type 053 * @param source the source iterable to search 054 * @param predicate the predicate used to test for presence 055 * @return {@link #PRESENT} if the iterable contains a matching item, otherwise 056 * {@link #ABSENT}. 057 */ 058 static <T> ConfigurationPropertyState search(Iterable<T> source, 059 Predicate<T> predicate) { 060 Assert.notNull(source, "Source must not be null"); 061 Assert.notNull(predicate, "Predicate must not be null"); 062 for (T item : source) { 063 if (predicate.test(item)) { 064 return PRESENT; 065 } 066 } 067 return ABSENT; 068 } 069 070}