1 /*
2 * Copyright 2002-2014 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.BeansException;
22 import org.springframework.context.ApplicationContext;
23 import org.springframework.core.Ordered;
24 import org.springframework.web.context.support.WebApplicationObjectSupport;
25 import org.springframework.web.servlet.View;
26 import org.springframework.web.servlet.ViewResolver;
27
28 /**
29 * A simple implementation of {@link org.springframework.web.servlet.ViewResolver}
30 * that interprets a view name as a bean name in the current application context,
31 * i.e. typically in the XML file of the executing {@code DispatcherServlet}.
32 *
33 * <p>This resolver can be handy for small applications, keeping all definitions
34 * ranging from controllers to views in the same place. For larger applications,
35 * {@link XmlViewResolver} will be the better choice, as it separates the XML
36 * view bean definitions into a dedicated views file.
37 *
38 * <p>Note: Neither this {@code ViewResolver} nor {@link XmlViewResolver} supports
39 * internationalization. Consider {@link ResourceBundleViewResolver} if you need
40 * to apply different view resources per locale.
41 *
42 * <p>Note: This {@code ViewResolver} implements the {@link Ordered} interface
43 * in order to allow for flexible participation in {@code ViewResolver} chaining.
44 * For example, some special views could be defined via this {@code ViewResolver}
45 * (giving it 0 as "order" value), while all remaining views could be resolved by
46 * a {@link UrlBasedViewResolver}.
47 *
48 * @author Juergen Hoeller
49 * @since 18.06.2003
50 * @see XmlViewResolver
51 * @see ResourceBundleViewResolver
52 * @see UrlBasedViewResolver
53 */
54 public class BeanNameViewResolver extends WebApplicationObjectSupport implements ViewResolver, Ordered {
55
56 private int order = Integer.MAX_VALUE; // default: same as non-Ordered
57
58
59 public void setOrder(int order) {
60 this.order = order;
61 }
62
63 @Override
64 public int getOrder() {
65 return this.order;
66 }
67
68
69 @Override
70 public View resolveViewName(String viewName, Locale locale) throws BeansException {
71 ApplicationContext context = getApplicationContext();
72 if (!context.containsBean(viewName)) {
73 if (logger.isDebugEnabled()) {
74 logger.debug("No matching bean found for view name '" + viewName + "'");
75 }
76 // Allow for ViewResolver chaining...
77 return null;
78 }
79 if (!context.isTypeMatch(viewName, View.class)) {
80 if (logger.isDebugEnabled()) {
81 logger.debug("Found matching bean for view name '" + viewName +
82 "' - to be ignored since it does not implement View");
83 }
84 // Since we're looking into the general ApplicationContext here,
85 // let's accept this as a non-match and allow for chaining as well...
86 return null;
87 }
88 return context.getBean(viewName, View.class);
89 }
90
91 }