001/* 002 * Copyright 2002-2018 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 * https://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.cache.interceptor; 018 019import java.io.Serializable; 020import java.util.Arrays; 021 022import org.springframework.util.Assert; 023import org.springframework.util.StringUtils; 024 025/** 026 * A simple key as returned from the {@link SimpleKeyGenerator}. 027 * 028 * @author Phillip Webb 029 * @since 4.0 030 * @see SimpleKeyGenerator 031 */ 032@SuppressWarnings("serial") 033public class SimpleKey implements Serializable { 034 035 /** 036 * An empty key. 037 */ 038 public static final SimpleKey EMPTY = new SimpleKey(); 039 040 041 private final Object[] params; 042 043 private final int hashCode; 044 045 046 /** 047 * Create a new {@link SimpleKey} instance. 048 * @param elements the elements of the key 049 */ 050 public SimpleKey(Object... elements) { 051 Assert.notNull(elements, "Elements must not be null"); 052 this.params = new Object[elements.length]; 053 System.arraycopy(elements, 0, this.params, 0, elements.length); 054 this.hashCode = Arrays.deepHashCode(this.params); 055 } 056 057 058 @Override 059 public boolean equals(Object other) { 060 return (this == other || 061 (other instanceof SimpleKey && Arrays.deepEquals(this.params, ((SimpleKey) other).params))); 062 } 063 064 @Override 065 public final int hashCode() { 066 return this.hashCode; 067 } 068 069 @Override 070 public String toString() { 071 return getClass().getSimpleName() + " [" + StringUtils.arrayToCommaDelimitedString(this.params) + "]"; 072 } 073 074}