1 /*
2 * Copyright 2002-2012 the original author or authors.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 package org.springframework.web.servlet.view;
18
19 import java.util.Locale;
20
21 import org.springframework.beans.factory.InitializingBean;
22
23 /**
24 * Abstract base class for URL-based views. Provides a consistent way of
25 * holding the URL that a View wraps, in the form of a "url" bean property.
26 *
27 * @author Juergen Hoeller
28 * @since 13.12.2003
29 */
30 public abstract class AbstractUrlBasedView extends AbstractView implements InitializingBean {
31
32 private String url;
33
34
35 /**
36 * Constructor for use as a bean.
37 */
38 protected AbstractUrlBasedView() {
39 }
40
41 /**
42 * Create a new AbstractUrlBasedView with the given URL.
43 * @param url the URL to forward to
44 */
45 protected AbstractUrlBasedView(String url) {
46 this.url = url;
47 }
48
49
50 /**
51 * Set the URL of the resource that this view wraps.
52 * The URL must be appropriate for the concrete View implementation.
53 */
54 public void setUrl(String url) {
55 this.url = url;
56 }
57
58 /**
59 * Return the URL of the resource that this view wraps.
60 */
61 public String getUrl() {
62 return this.url;
63 }
64
65 @Override
66 public void afterPropertiesSet() throws Exception {
67 if (isUrlRequired() && getUrl() == null) {
68 throw new IllegalArgumentException("Property 'url' is required");
69 }
70 }
71
72 /**
73 * Return whether the 'url' property is required.
74 * <p>The default implementation returns {@code true}.
75 * This can be overridden in subclasses.
76 */
77 protected boolean isUrlRequired() {
78 return true;
79 }
80
81 /**
82 * Check whether the underlying resource that the configured URL points to
83 * actually exists.
84 * @param locale the desired Locale that we're looking for
85 * @return {@code true} if the resource exists (or is assumed to exist);
86 * {@code false} if we know that it does not exist
87 * @throws Exception if the resource exists but is invalid (e.g. could not be parsed)
88 */
89 public boolean checkResource(Locale locale) throws Exception {
90 return true;
91 }
92
93 @Override
94 public String toString() {
95 StringBuilder sb = new StringBuilder(super.toString());
96 sb.append("; URL [").append(getUrl()).append("]");
97 return sb.toString();
98 }
99
100 }