package org.apache.commons.betwixt.digester;
/*
* ====================================================================
*
* The Apache Software License, Version 1.1
*
* Copyright (c) 1999-2002 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
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*
* 2. Redistributions in binary form must reproduce the above copyright
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* distribution.
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* 3. The end-user documentation included with the redistribution, if
* any, must include the following acknowlegement:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowlegement may appear in the software itself,
* if and wherever such third-party acknowlegements normally appear.
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* 4. The names "The Jakarta Project", "Commons", and "Apache Software
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
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* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*/
import java.beans.BeanInfo;
import java.beans.Introspector;
import java.beans.PropertyDescriptor;
import org.apache.commons.betwixt.AttributeDescriptor;
import org.apache.commons.betwixt.ElementDescriptor;
import org.apache.commons.betwixt.expression.ConstantExpression;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
/**
* <p><code>AttributeRule</code> the digester Rule for parsing the
* <attribute> elements.</p>
*
* @author <a href="mailto:jstrachan@apache.org">James Strachan</a>
* @version $Id: AttributeRule.java,v 1.5 2003/01/07 22:32:57 rdonkin Exp $
*/
public class AttributeRule extends RuleSupport {
/** Logger */
private static final Log log = LogFactory.getLog( AttributeRule.class );
/** This loads all classes created by name. Defaults to this class's classloader */
private ClassLoader classLoader;
/** The <code>Class</code> whose .betwixt file is being digested */
private Class beanClass;
/** Base constructor */
public AttributeRule() {
this.classLoader = getClass().getClassLoader();
}
// Rule interface
//-------------------------------------------------------------------------
/**
* Process the beginning of this element.
*
* @param attributes The attribute list of this element
* @throws SAXException if the attribute tag is not inside an element tag
*/
public void begin(Attributes attributes) throws SAXException {
AttributeDescriptor descriptor = new AttributeDescriptor();
String name = attributes.getValue( "name" );
descriptor.setQualifiedName( name );
descriptor.setLocalName( name );
String uri = attributes.getValue( "uri" );
if ( uri != null ) {
descriptor.setURI( uri );
}
String propertyName = attributes.getValue( "property" );
descriptor.setPropertyName( propertyName );
descriptor.setPropertyType( loadClass( attributes.getValue( "type" ) ) );
if ( propertyName != null && propertyName.length() > 0 ) {
configureDescriptor(descriptor);
} else {
String value = attributes.getValue( "value" );
if ( value != null ) {
descriptor.setTextExpression( new ConstantExpression( value ) );
}
}
Object top = digester.peek();
if ( top instanceof ElementDescriptor ) {
ElementDescriptor parent = (ElementDescriptor) top;
parent.addAttributeDescriptor( descriptor );
} else {
throw new SAXException( "Invalid use of <attribute>. It should "
+ "be nested inside an <element> element" );
}
digester.push(descriptor);
}
/**
* Process the end of this element.
*/
public void end() {
Object top = digester.pop();
}
// Implementation methods
//-------------------------------------------------------------------------
/**
* Loads a class (using the appropriate classloader)
*
* @param name the name of the class to load
* @return the class instance loaded by the appropriate classloader
*/
protected Class loadClass( String name ) {
// XXX: should use a ClassLoader to handle complex class loading situations
if ( name != null ) {
try {
return classLoader.loadClass(name);
} catch (Exception e) { // SWALLOW
}
}
return null;
}
/**
* Set the Expression and Updater from a bean property name
* @param attributeDescriptor configure this <code>AttributeDescriptor</code>
* from the property with a matching name in the bean class
*/
protected void configureDescriptor(AttributeDescriptor attributeDescriptor) {
Class beanClass = getBeanClass();
if ( beanClass != null ) {
String name = attributeDescriptor.getPropertyName();
try {
BeanInfo beanInfo = Introspector.getBeanInfo( beanClass );
PropertyDescriptor[] descriptors = beanInfo.getPropertyDescriptors();
if ( descriptors != null ) {
for ( int i = 0, size = descriptors.length; i < size; i++ ) {
PropertyDescriptor descriptor = descriptors[i];
if ( name.equals( descriptor.getName() ) ) {
XMLIntrospectorHelper
.configureProperty( attributeDescriptor, descriptor );
getProcessedPropertyNameSet().add( name );
break;
}
}
}
} catch (Exception e) {
log.warn( "Caught introspection exception", e );
}
}
}
}