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.web.reactive.result.view; 018 019import java.util.Locale; 020 021import org.springframework.beans.factory.InitializingBean; 022import org.springframework.lang.Nullable; 023 024/** 025 * Abstract base class for URL-based views. Provides a consistent way of 026 * holding the URL that a View wraps, in the form of a "url" bean property. 027 * 028 * @author Rossen Stoyanchev 029 * @since 5.0 030 */ 031public abstract class AbstractUrlBasedView extends AbstractView implements InitializingBean { 032 033 @Nullable 034 private String url; 035 036 037 /** 038 * Constructor for use as a bean. 039 */ 040 protected AbstractUrlBasedView() { 041 } 042 043 /** 044 * Create a new AbstractUrlBasedView with the given URL. 045 */ 046 protected AbstractUrlBasedView(String url) { 047 this.url = url; 048 } 049 050 051 /** 052 * Set the URL of the resource that this view wraps. 053 * The URL must be appropriate for the concrete View implementation. 054 */ 055 public void setUrl(@Nullable String url) { 056 this.url = url; 057 } 058 059 /** 060 * Return the URL of the resource that this view wraps. 061 */ 062 @Nullable 063 public String getUrl() { 064 return this.url; 065 } 066 067 068 @Override 069 public void afterPropertiesSet() throws Exception { 070 if (getUrl() == null) { 071 throw new IllegalArgumentException("Property 'url' is required"); 072 } 073 } 074 075 /** 076 * Check whether the resource for the configured URL actually exists. 077 * @param locale the desired Locale that we're looking for 078 * @return {@code false} if the resource exists 079 * {@code false} if we know that it does not exist 080 * @throws Exception if the resource exists but is invalid (e.g. could not be parsed) 081 */ 082 public abstract boolean checkResourceExists(Locale locale) throws Exception; 083 084 085 @Override 086 public String toString() { 087 return super.toString() + "; URL [" + getUrl() + "]"; 088 } 089 090}