/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.catalina.storeconfig;
import org.apache.tomcat.util.digester.Rule;
import org.xml.sax.Attributes;
/**
* <p>
* Rule that creates a new <code>IStoreFactory</code> instance, and associates
* it with the top object on the stack (which must implement
* <code>IStoreFactory</code>).
* </p>
*/
public class StoreFactoryRule extends Rule {
// ----------------------------------------------------------- Constructors
/**
* Construct a new instance of this Rule.
*
* @param storeFactoryClass
* Default name of the StoreFactory implementation class to be
* created
* @param attributeName
* Name of the attribute that optionally includes an override
* name of the IStoreFactory class
* @param storeAppenderClass The store appender class
* @param appenderAttributeName The attribute name for the store
* appender class
*/
public StoreFactoryRule(String storeFactoryClass, String attributeName,
String storeAppenderClass, String appenderAttributeName) {
this.storeFactoryClass = storeFactoryClass;
this.attributeName = attributeName;
this.appenderAttributeName = appenderAttributeName;
this.storeAppenderClass = storeAppenderClass;
}
// ----------------------------------------------------- Instance Variables
/**
* The attribute name of an attribute that can override the implementation
* class name.
*/
private String attributeName;
private String appenderAttributeName;
/**
* The name of the <code>IStoreFactory</code> implementation class.
*/
private String storeFactoryClass;
private String storeAppenderClass;
// --------------------------------------------------------- Public Methods
/**
* Handle the beginning of an XML element.
*
* @param namespace XML namespace
* @param name The element name
* @param attributes The attributes of this element
* @exception Exception if a processing error occurs
*/
@Override
public void begin(String namespace, String name, Attributes attributes)
throws Exception {
IStoreFactory factory = (IStoreFactory) newInstance(attributeName,
storeFactoryClass, attributes);
StoreAppender storeAppender = (StoreAppender) newInstance(
appenderAttributeName, storeAppenderClass, attributes);
factory.setStoreAppender(storeAppender);
// Add this StoreFactory to our associated component
StoreDescription desc = (StoreDescription) digester.peek(0);
StoreRegistry registry = (StoreRegistry) digester.peek(1);
factory.setRegistry(registry);
desc.setStoreFactory(factory);
}
/**
* Create new instance from attribute className!
*
* @param attr class Name attribute
* @param defaultName Default Class
* @param attributes current digester attribute elements
* @return new configured object instance
* @throws ClassNotFoundException Class was not found
* @throws InstantiationException Error creating an instance
* @throws IllegalAccessException Security exception
*/
protected Object newInstance(String attr, String defaultName,
Attributes attributes) throws ClassNotFoundException,
InstantiationException, IllegalAccessException {
String className = defaultName;
if (attr != null) {
String value = attributes.getValue(attr);
if (value != null)
className = value;
}
Class<?> clazz = Class.forName(className);
return clazz.newInstance();
}
}