1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17 package org.apache.commons.betwixt.digester;
18
19 import java.beans.BeanInfo;
20 import java.beans.Introspector;
21 import java.beans.PropertyDescriptor;
22
23 import org.apache.commons.logging.Log;
24 import org.apache.commons.logging.LogFactory;
25
26 /** <p>Factors out common code used by Betwixt rules that access bean properties.
27 * Maybe a lot of this should be moved into <code>BeanUtils</code>.</p>
28 *
29 * @author Robert Burrell Donkin
30 * @since 0.5
31 */
32 public abstract class MappedPropertyRule extends RuleSupport {
33
34 /** Logger */
35 private static final Log log = LogFactory.getLog( MappedPropertyRule.class );
36 /** Base constructor */
37 public MappedPropertyRule() {
38 }
39
40
41
42 // Implementation methods
43 //-------------------------------------------------------------------------
44
45 /**
46 * Returns the property descriptor for the class and property name.
47 * Note that some caching could be used to improve performance of
48 * this method. Or this method could be added to PropertyUtils.
49 *
50 * @param beanClass descriptor for property in this class
51 * @param propertyName descriptor for property with this name
52 * @return property descriptor for the named property in the given class
53 */
54 protected PropertyDescriptor getPropertyDescriptor( Class beanClass,
55 String propertyName ) {
56 if ( beanClass != null && propertyName != null ) {
57 if (log.isTraceEnabled()) {
58 log.trace("Searching for property " + propertyName + " on " + beanClass);
59 }
60 try {
61 // TODO: replace this call to introspector to an object call
62 // which finds all property descriptors for a class
63 // this allows extra property descriptors to be added
64 BeanInfo beanInfo;
65 if( getXMLIntrospector().getConfiguration().ignoreAllBeanInfo() ) {
66 beanInfo = Introspector.getBeanInfo( beanClass, Introspector.IGNORE_ALL_BEANINFO );
67 }
68 else {
69 beanInfo = Introspector.getBeanInfo( beanClass );
70 }
71 PropertyDescriptor[] descriptors =
72 beanInfo.getPropertyDescriptors();
73 if ( descriptors != null ) {
74 for ( int i = 0, size = descriptors.length; i < size; i++ ) {
75 PropertyDescriptor descriptor = descriptors[i];
76 if ( propertyName.equals( descriptor.getName() ) ) {
77 log.trace("Found matching method.");
78 return descriptor;
79 }
80 }
81 }
82 // for interfaces, check all super interfaces
83 if (beanClass.isInterface()) {
84 Class[] superinterfaces = beanClass.getInterfaces();
85 for (int i=0, size=superinterfaces.length; i<size; i++) {
86 PropertyDescriptor descriptor = getPropertyDescriptor(superinterfaces[i], propertyName);
87 if (descriptor != null)
88 {
89 return descriptor;
90 }
91 }
92 }
93
94 log.trace("No match found.");
95 return null;
96 } catch (Exception e) {
97 log.warn( "Caught introspection exception", e );
98 }
99 }
100 return null;
101 }
102
103
104 /**
105 * Gets the type of a property
106 *
107 * @param propertyClassName class name for property type (may be null)
108 * @param beanClass class that has property
109 * @param propertyName the name of the property whose type is to be determined
110 * @return property type
111 */
112 protected Class getPropertyType( String propertyClassName,
113 Class beanClass, String propertyName ) {
114 // XXX: should use a ClassLoader to handle
115 // complex class loading situations
116 if ( propertyClassName != null ) {
117 try {
118 Class answer = loadClass(propertyClassName);
119 if (answer != null) {
120 if (log.isTraceEnabled()) {
121 log.trace("Used specified type " + answer);
122 }
123 return answer;
124 }
125 } catch (Exception e) {
126 log.warn("Cannot load specified type", e);
127 }
128 }
129
130 PropertyDescriptor descriptor =
131 getPropertyDescriptor( beanClass, propertyName );
132 if ( descriptor != null ) {
133 return descriptor.getPropertyType();
134 }
135
136 if (log.isTraceEnabled()) {
137 log.trace("Cannot find property type.");
138 log.trace(" className=" + propertyClassName
139 + " base=" + beanClass + " name=" + propertyName);
140 }
141 return null;
142 }
143 }