001/*
002 * Copyright 2002-2017 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 *      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.core;
018
019import java.lang.reflect.Method;
020
021import org.springframework.lang.Nullable;
022import org.springframework.util.ObjectUtils;
023
024/**
025 * A common key class for a method against a specific target class,
026 * including {@link #toString()} representation and {@link Comparable}
027 * support (as suggested for custom {@code HashMap} keys as of Java 8).
028 *
029 * @author Juergen Hoeller
030 * @since 4.3
031 */
032public final class MethodClassKey implements Comparable<MethodClassKey> {
033
034        private final Method method;
035
036        @Nullable
037        private final Class<?> targetClass;
038
039
040        /**
041         * Create a key object for the given method and target class.
042         * @param method the method to wrap (must not be {@code null})
043         * @param targetClass the target class that the method will be invoked
044         * on (may be {@code null} if identical to the declaring class)
045         */
046        public MethodClassKey(Method method, @Nullable Class<?> targetClass) {
047                this.method = method;
048                this.targetClass = targetClass;
049        }
050
051
052        @Override
053        public boolean equals(@Nullable Object other) {
054                if (this == other) {
055                        return true;
056                }
057                if (!(other instanceof MethodClassKey)) {
058                        return false;
059                }
060                MethodClassKey otherKey = (MethodClassKey) other;
061                return (this.method.equals(otherKey.method) &&
062                                ObjectUtils.nullSafeEquals(this.targetClass, otherKey.targetClass));
063        }
064
065        @Override
066        public int hashCode() {
067                return this.method.hashCode() + (this.targetClass != null ? this.targetClass.hashCode() * 29 : 0);
068        }
069
070        @Override
071        public String toString() {
072                return this.method + (this.targetClass != null ? " on " + this.targetClass : "");
073        }
074
075        @Override
076        public int compareTo(MethodClassKey other) {
077                int result = this.method.getName().compareTo(other.method.getName());
078                if (result == 0) {
079                        result = this.method.toString().compareTo(other.method.toString());
080                        if (result == 0 && this.targetClass != null && other.targetClass != null) {
081                                result = this.targetClass.getName().compareTo(other.targetClass.getName());
082                        }
083                }
084                return result;
085        }
086
087}