001/* 002 * Copyright 2002-2019 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.web.servlet.mvc.condition; 018 019import java.util.Collection; 020import java.util.StringJoiner; 021 022import org.springframework.lang.Nullable; 023 024/** 025 * A base class for {@link RequestCondition} types providing implementations of 026 * {@link #equals(Object)}, {@link #hashCode()}, and {@link #toString()}. 027 * 028 * @author Rossen Stoyanchev 029 * @since 3.1 030 * @param <T> the type of objects that this RequestCondition can be combined 031 * with and compared to 032 */ 033public abstract class AbstractRequestCondition<T extends AbstractRequestCondition<T>> implements RequestCondition<T> { 034 035 /** 036 * Indicates whether this condition is empty, i.e. whether or not it 037 * contains any discrete items. 038 * @return {@code true} if empty; {@code false} otherwise 039 */ 040 public boolean isEmpty() { 041 return getContent().isEmpty(); 042 } 043 044 /** 045 * Return the discrete items a request condition is composed of. 046 * <p>For example URL patterns, HTTP request methods, param expressions, etc. 047 * @return a collection of objects (never {@code null}) 048 */ 049 protected abstract Collection<?> getContent(); 050 051 /** 052 * The notation to use when printing discrete items of content. 053 * <p>For example {@code " || "} for URL patterns or {@code " && "} 054 * for param expressions. 055 */ 056 protected abstract String getToStringInfix(); 057 058 059 @Override 060 public boolean equals(@Nullable Object other) { 061 if (this == other) { 062 return true; 063 } 064 if (other == null || getClass() != other.getClass()) { 065 return false; 066 } 067 return getContent().equals(((AbstractRequestCondition<?>) other).getContent()); 068 } 069 070 @Override 071 public int hashCode() { 072 return getContent().hashCode(); 073 } 074 075 @Override 076 public String toString() { 077 String infix = getToStringInfix(); 078 StringJoiner joiner = new StringJoiner(infix, "[", "]"); 079 for (Object expression : getContent()) { 080 joiner.add(expression.toString()); 081 } 082 return joiner.toString(); 083 } 084 085}