/*
* Copyright 2007 Ralf Joachim
*
* Licensed 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.castor.cpa.persistence.convertor;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import org.castor.core.util.AbstractProperties;
import org.castor.cpa.CPAProperties;
import org.exolab.castor.mapping.MappingException;
/**
* Registry of type convertors.
*
* @author <a href="mailto:ralf DOT joachim AT syscon DOT eu">Ralf Joachim</a>
* @version $Revision: 7134 $ $Date: 2006-04-25 15:08:23 -0600 (Tue, 25 Apr 2006) $
* @since 1.1.3
*/
public final class TypeConvertorRegistry {
//-----------------------------------------------------------------------------------
/** Map of maps of type converters. For the outer one the key is <tt>fromType</tt>
* while the key of the inner one is <tt>toType</tt>. */
private final Map<Class<?>, Map<Class<?>, TypeConvertor>> _convertors
= new HashMap<Class<?>, Map<Class<?>, TypeConvertor>>();
//-----------------------------------------------------------------------------------
/**
* Create a new registry instance of type convertors. The registry will be initialized
* with all type convertors specified through <b>TYPE_CONVERTORS</b> property of given
* properties. The properties get also passed to the type converters for them to
* get any required property.
*
* @param properties The properties to use.
*/
public TypeConvertorRegistry(final AbstractProperties properties) {
Object[] objects = properties.getObjectArray(
CPAProperties.TYPE_CONVERTORS, properties.getApplicationClassLoader());
for (int i = 0; i < objects.length; i++) {
TypeConvertor convertor = (TypeConvertor) objects[i];
convertor.configure(properties);
putConvertor(convertor.fromType(), convertor.toType(), convertor);
}
}
//-----------------------------------------------------------------------------------
/**
* Put given type convertor in map of maps of convertors.
*
* @param fromType The Java type to convert from.
* @param toType The Java type to convert to.
* @param convertor The TypeConverter to convert fromType into toType.
*/
private void putConvertor(final Class<?> fromType, final Class<?> toType,
final TypeConvertor convertor) {
Map<Class<?>, TypeConvertor> convertors = _convertors.get(fromType);
if (convertors == null) {
convertors = new HashMap<Class<?>, TypeConvertor>();
_convertors.put(fromType, convertors);
}
convertors.put(toType, convertor);
}
/**
* Returns a type convertor. A type convertor can be used to convert
* an object from Java type <tt>fromType</tt> to Java type <tt>toType</tt>.
*
* @param fromType The Java type to convert from.
* @param toType The Java type to convert to.
* @return The TypeConverter to convert fromType into toType.
* @throws MappingException No suitable convertor was found.
*/
private TypeConvertor getConvertor(final Class<?> fromType, final Class<?> toType)
throws MappingException {
TypeConvertor convertor = null;
// first search exact match of from and to type.
Map<Class<?>, TypeConvertor> convertors = _convertors.get(fromType);
if (convertors != null) {
convertor = convertors.get(toType);
}
// if not found yet search assignment compatible from and to type.
if (convertor == null) {
Iterator<Map.Entry<Class<?>, Map<Class<?>, TypeConvertor>>> fromIter;
fromIter = _convertors.entrySet().iterator();
while ((convertor == null) && fromIter.hasNext()) {
Map.Entry<Class<?>, Map<Class<?>, TypeConvertor>> fromEntry;
fromEntry = fromIter.next();
if (fromEntry.getKey().isAssignableFrom(fromType)) {
convertors = fromEntry.getValue();
Iterator<Map.Entry<Class<?>, TypeConvertor>> toIter;
toIter = convertors.entrySet().iterator();
while ((convertor == null) && toIter.hasNext()) {
Map.Entry<Class<?>, TypeConvertor> toEntry = toIter.next();
if (toEntry.getKey().isAssignableFrom(toType)) {
convertor = toEntry.getValue();
}
}
}
}
// if still not found throw an exception.
if (convertor == null) {
throw new MappingException("mapping.noConvertor",
fromType.getName(), toType.getName());
}
// put the assignment compatible convertor found into the map
// for faster retrieval when it is needed a second time.
putConvertor(fromType, toType, convertor);
}
return convertor;
}
/**
* Returns a type convertor initialized with parameter if specified. A type convertor
* can be used to convert an object from Java type <tt>fromType</tt> to Java type
* <tt>toType</tt>.
*
* @param fromType The Java type to convert from.
* @param toType The Java type to convert to.
* @param parameter The parameter for the convertor (null if is not specified).
* @return The TypeConverter to convert fromType into toType.
* @throws MappingException No suitable convertor was found.
*/
public TypeConvertor getConvertor(final Class<?> fromType, final Class<?> toType,
final String parameter) throws MappingException {
TypeConvertor convertor = getConvertor(fromType, toType);
// if a parameter is to be set, create a clone of the type convertor
// and initialize it with the parameter given.
if (parameter != null) {
convertor = (TypeConvertor) convertor.clone();
convertor.parameterize(parameter);
}
return convertor;
}
//-----------------------------------------------------------------------------------
}