1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one or more 3 * contributor license agreements. See the NOTICE file distributed with 4 * this work for additional information regarding copyright ownership. 5 * The ASF licenses this file to You under the Apache license, Version 2.0 6 * (the "License"); you may not use this file except in compliance with 7 * the License. You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the license for the specific language governing permissions and 15 * limitations under the license. 16 */ 17 18 package org.apache.logging.log4j.util; 19 20 import org.apache.logging.log4j.message.Message; 21 22 23 /** 24 * Utility class for lambda support. 25 */ 26 public class LambdaUtil { 27 /** 28 * Private constructor: this class is not intended to be instantiated. 29 */ 30 private LambdaUtil() { 31 } 32 33 /** 34 * Converts an array of lambda expressions into an array of their evaluation results. 35 * 36 * @param suppliers an array of lambda expressions or {@code null} 37 * @return an array containing the results of evaluating the lambda expressions (or {@code null} if the suppliers 38 * array was {@code null} 39 */ 40 public static Object[] getAll(final Supplier<?>... suppliers) { 41 if (suppliers == null) { 42 return null; 43 } 44 final Object[] result = new Object[suppliers.length]; 45 for (int i = 0; i < result.length; i++) { 46 result[i] = get(suppliers[i]); 47 } 48 return result; 49 } 50 51 /** 52 * Returns the result of evaluating the specified function. 53 * @param supplier a lambda expression or {@code null} 54 * @return the results of evaluating the lambda expression (or {@code null} if the supplier 55 * was {@code null} 56 */ 57 public static Object get(final Supplier<?> supplier) { 58 if (supplier == null) { 59 return null; 60 } 61 return supplier.get(); 62 } 63 64 /** 65 * Returns the Message supplied by the specified function. 66 * @param supplier a lambda expression or {@code null} 67 * @return the Message resulting from evaluating the lambda expression (or {@code null} if the supplier was 68 * {@code null} 69 */ 70 public static Message get(final MessageSupplier supplier) { 71 if (supplier == null) { 72 return null; 73 } 74 return supplier.get(); 75 } 76 }