001 /**
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements. See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License. You may obtain a copy of the License at
008 *
009 * http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017 package org.apache.camel.spring.handler;
018
019 import org.w3c.dom.Attr;
020 import org.w3c.dom.Element;
021 import org.w3c.dom.NamedNodeMap;
022
023 import org.springframework.beans.factory.support.BeanDefinitionBuilder;
024 import org.springframework.beans.factory.xml.AbstractSingleBeanDefinitionParser;
025 import org.springframework.core.Conventions;
026 import org.springframework.util.Assert;
027 import org.springframework.util.StringUtils;
028
029 /**
030 * A base class for a parser for a bean.
031 *
032 * @version $Revision: 927682 $
033 */
034 // TODO cannot use AbstractSimpleBeanDefinitionParser
035 // as doParse() is final and isEligableAttribute does not allow us to filter out attributes
036 // with the name "xmlns:"
037 public class BeanDefinitionParser extends AbstractSingleBeanDefinitionParser {
038 private Class type;
039
040 public BeanDefinitionParser(Class type) {
041 this.type = type;
042 }
043
044 protected Class getBeanClass(Element element) {
045 return type;
046 }
047
048 protected boolean isEligibleAttribute(String attributeName) {
049 return attributeName != null && !ID_ATTRIBUTE.equals(attributeName)
050 && !attributeName.equals("xmlns") && !attributeName.startsWith("xmlns:");
051 }
052
053 // TODO the following code is copied from AbstractSimpleBeanDefinitionParser
054 // it can be removed if ever the doParse() method is not final!
055 // or the Spring bug http://jira.springframework.org/browse/SPR-4599 is resolved
056
057 /**
058 * Parse the supplied {@link Element} and populate the supplied
059 * {@link BeanDefinitionBuilder} as required.
060 * <p>This implementation maps any attributes present on the
061 * supplied element to {@link org.springframework.beans.PropertyValue}
062 * instances, and
063 * {@link BeanDefinitionBuilder#addPropertyValue(String, Object) adds them}
064 * to the
065 * {@link org.springframework.beans.factory.config.BeanDefinition builder}.
066 * <p>The {@link #extractPropertyName(String)} method is used to
067 * reconcile the name of an attribute with the name of a JavaBean
068 * property.
069 *
070 * @param element the XML element being parsed
071 * @param builder used to define the <code>BeanDefinition</code>
072 * @see #extractPropertyName(String)
073 */
074 protected final void doParse(Element element, BeanDefinitionBuilder builder) {
075 NamedNodeMap attributes = element.getAttributes();
076 for (int x = 0; x < attributes.getLength(); x++) {
077 Attr attribute = (Attr) attributes.item(x);
078 String name = attribute.getLocalName();
079 String fullName = attribute.getName();
080 if (!fullName.startsWith("xmlns:") && !fullName.equals("xmlns") && isEligibleAttribute(name)) {
081 String propertyName = extractPropertyName(name);
082 Assert.state(StringUtils.hasText(propertyName),
083 "Illegal property name returned from 'extractPropertyName(String)': cannot be null or empty.");
084 builder.addPropertyValue(propertyName, attribute.getValue());
085 }
086 }
087 postProcess(builder, element);
088 }
089
090
091 /**
092 * Extract a JavaBean property name from the supplied attribute name.
093 * <p>The default implementation uses the
094 * {@link Conventions#attributeNameToPropertyName(String)}
095 * method to perform the extraction.
096 * <p>The name returned must obey the standard JavaBean property name
097 * conventions. For example for a class with a setter method
098 * '<code>setBingoHallFavourite(String)</code>', the name returned had
099 * better be '<code>bingoHallFavourite</code>' (with that exact casing).
100 *
101 * @param attributeName the attribute name taken straight from the
102 * XML element being parsed (never <code>null</code>)
103 * @return the extracted JavaBean property name (must never be <code>null</code>)
104 */
105 protected String extractPropertyName(String attributeName) {
106 return Conventions.attributeNameToPropertyName(attributeName);
107 }
108
109 /**
110 * Hook method that derived classes can implement to inspect/change a
111 * bean definition after parsing is complete.
112 * <p>The default implementation does nothing.
113 *
114 * @param beanDefinition the parsed (and probably totally defined) bean definition being built
115 * @param element the XML element that was the source of the bean definition's metadata
116 */
117 protected void postProcess(BeanDefinitionBuilder beanDefinition, Element element) {
118 }
119
120 }