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