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.commons.function; 018 019import static org.apache.juneau.commons.utils.AssertionUtils.*; 020 021/** 022 * A functional interface representing an operation that accepts four arguments and returns no result. 023 * 024 * <p> 025 * This interface extends the standard Java {@link java.util.function.Consumer} pattern to support 026 * four-argument consumers. It's useful when you need to pass operations with four parameters to methods 027 * that expect functional interfaces, such as in iteration, builders, or callback patterns. 028 * 029 * <h5 class='section'>Features:</h5> 030 * <ul class='spaced-list'> 031 * <li>Functional interface - can be used with lambda expressions and method references 032 * <li>Composition support - provides {@link #andThen(Consumer4)} for operation chaining 033 * <li>Side-effect operations - designed for operations that perform side effects rather than return values 034 * </ul> 035 * 036 * <h5 class='section'>Use Cases:</h5> 037 * <ul class='spaced-list'> 038 * <li>Four-argument operations in iteration patterns 039 * <li>Builder methods that accept four-parameter operations 040 * <li>Callback patterns with four parameters 041 * <li>Event handlers that process four values 042 * </ul> 043 * 044 * <h5 class='section'>Usage:</h5> 045 * <p class='bjava'> 046 * <jc>// Lambda expression</jc> 047 * Consumer4<String,Integer,Boolean,Double> <jv>printer</jv> = (<jv>name</jv>, <jv>age</jv>, <jv>active</jv>, <jv>score</jv>) -> 048 * System.<jsf>out</jsf>.println(<jv>name</jv> + <js>": age="</js> + <jv>age</jv> + <js>", active="</js> + <jv>active</jv> + <js>", score="</js> + <jv>score</jv>); 049 * <jv>printer</jv>.apply(<js>"Alice"</js>, 30, <jk>true</jk>, 95.5); <jc>// Prints "Alice: age=30, active=true, score=95.5"</jc> 050 * 051 * <jc>// Operation composition</jc> 052 * Consumer4<String,Integer,Boolean,Double> <jv>validate</jv> = (<jv>s</jv>, <jv>i</jv>, <jv>b</jv>, <jv>d</jv>) -> { 053 * <jk>if</jk> (<jv>i</jv> < 0 || <jv>d</jv> < 0) <jk>throw new</jk> IllegalArgumentException(); 054 * }; 055 * Consumer4<String,Integer,Boolean,Double> <jv>process</jv> = (<jv>s</jv>, <jv>i</jv>, <jv>b</jv>, <jv>d</jv>) -> <jsm>process</jsm>(<jv>s</jv>, <jv>i</jv>, <jv>b</jv>, <jv>d</jv>); 056 * Consumer4<String,Integer,Boolean,Double> <jv>validateAndProcess</jv> = <jv>validate</jv>.andThen(<jv>process</jv>); 057 * <jv>validateAndProcess</jv>.apply(<js>"data"</js>, 42, <jk>true</jk>, 10.5); <jc>// Validates then processes</jc> 058 * </p> 059 * 060 * <h5 class='section'>See Also:</h5><ul> 061 * <li class='jc'>{@link Consumer2} - Two-argument consumer 062 * <li class='jc'>{@link Consumer3} - Three-argument consumer 063 * <li class='jc'>{@link Consumer5} - Five-argument consumer 064 * <li class='link'><a class="doclink" href="https://juneau.apache.org/docs/topics/JuneauCommonsBasics">juneau-commons Basics</a> 065 * </ul> 066 * 067 * @param <A> The type of the first argument to the operation. 068 * @param <B> The type of the second argument to the operation. 069 * @param <C> The type of the third argument to the operation. 070 * @param <D> The type of the fourth argument to the operation. 071 */ 072@FunctionalInterface 073public interface Consumer4<A,B,C,D> { 074 075 /** 076 * Returns a composed {@link Consumer4} that performs, in sequence, this operation followed by the {@code after} operation. 077 * 078 * <p> 079 * This method enables operation composition, allowing you to chain multiple operations together. 080 * If performing either operation throws an exception, it is relayed to the caller of the composed operation. 081 * If performing this operation throws an exception, the {@code after} operation will not be performed. 082 * 083 * <h5 class='section'>Example:</h5> 084 * <p class='bjava'> 085 * Consumer4<String,Integer,Boolean,Double> <jv>log</jv> = (<jv>s</jv>, <jv>i</jv>, <jv>b</jv>, <jv>d</jv>) -> <jsm>logger</jsm>.info(<jv>s</jv> + <js>": "</js> + <jv>i</jv> + <js>", "</js> + <jv>b</jv> + <js>", "</js> + <jv>d</jv>); 086 * Consumer4<String,Integer,Boolean,Double> <jv>store</jv> = (<jv>s</jv>, <jv>i</jv>, <jv>b</jv>, <jv>d</jv>) -> <jv>cache</jv>.put(<jv>s</jv>, <jv>i</jv>, <jv>b</jv>, <jv>d</jv>); 087 * Consumer4<String,Integer,Boolean,Double> <jv>logAndStore</jv> = <jv>log</jv>.andThen(<jv>store</jv>); 088 * <jv>logAndStore</jv>.apply(<js>"data"</js>, 100, <jk>true</jk>, 50.0); <jc>// Logs and stores</jc> 089 * </p> 090 * 091 * @param after The operation to perform after this operation. Must not be <jk>null</jk>. 092 * @return A composed {@link Consumer4} that performs in sequence this operation followed by the {@code after} operation. 093 * @throws NullPointerException if {@code after} is <jk>null</jk>. 094 */ 095 default Consumer4<A,B,C,D> andThen(Consumer4<? super A,? super B,? super C,? super D> after) { // NOSONAR - false positive on generics 096 assertArgNotNull("after", after); 097 return (A a, B b, C c, D d) -> { 098 apply(a, b, c, d); 099 after.apply(a, b, c, d); 100 }; 101 } 102 103 /** 104 * Performs this operation on the given arguments. 105 * 106 * <h5 class='section'>Example:</h5> 107 * <p class='bjava'> 108 * Consumer4<String,Integer,Boolean,Double> <jv>handler</jv> = (<jv>key</jv>, <jv>value</jv>, <jv>flag</jv>, <jv>weight</jv>) -> { 109 * <jv>map</jv>.put(<jv>key</jv>, <jv>value</jv>); 110 * <jk>if</jk> (<jv>flag</jv>) <jv>cache</jv>.invalidate(<jv>key</jv>); 111 * <jv>stats</jv>.record(<jv>weight</jv>); 112 * }; 113 * <jv>handler</jv>.apply(<js>"user"</js>, 12345, <jk>true</jk>, 1.5); 114 * </p> 115 * 116 * @param a The first operation argument. 117 * @param b The second operation argument. 118 * @param c The third operation argument. 119 * @param d The fourth operation argument. 120 */ 121 void apply(A a, B b, C c, D d); 122}