/*
* Copyright 2011 the original author or authors.
*
* 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.modelmapper.internal.converter;
import java.lang.reflect.Array;
import java.util.Collection;
import java.util.Iterator;
import org.modelmapper.internal.util.ArrayIterator;
import org.modelmapper.spi.ConditionalConverter;
import org.modelmapper.spi.MappingContext;
/**
* Support class for converting Iterable and psuedo-Iterable (array) instances. Implementors must
* support source and destination types that are Iterable or array instances.
*
* @author Jonathan Halterman
*/
abstract class IterableConverter<S, D> implements ConditionalConverter<S, D> {
public D convert(MappingContext<S, D> context) {
S source = context.getSource();
if (source == null)
return null;
int sourceLength = getSourceLength(source);
D destination = context.getDestination() == null ? createDestination(context, sourceLength)
: context.getDestination();
Class<?> elementType = getElementType(context);
int index = 0;
for (Iterator<Object> iterator = getSourceIterator(source); iterator.hasNext(); index++) {
Object sourceElement = iterator.next();
Object element = null;
if (sourceElement != null) {
MappingContext<?, ?> elementContext = context.create(sourceElement, elementType);
element = context.getMappingEngine().map(elementContext);
}
setElement(destination, element, index);
}
return destination;
}
/**
* Creates a destination instance for the {@code destinationType} where the destination supports
* element {@code length}.
*/
protected abstract D createDestination(MappingContext<S, D> context, int length);
/**
* Gets the contained element type for the {@code type} and nullable {@code genericType}.
*
* @param type to retrieve element type for
* @param genericType to retrieve element type for - maybe be null
*/
protected Class<?> getElementType(MappingContext<S, D> context) {
return Object.class;
}
/**
* Gets an Iterator for the Iterable or psuedo-Iterable (array) {@code source}.
*/
@SuppressWarnings("unchecked")
protected Iterator<Object> getSourceIterator(S source) {
return source.getClass().isArray() ? new ArrayIterator(source)
: ((Iterable<Object>) source).iterator();
}
/**
* Gets the source length of the Iterable or psuedo-Iterable (array) {@code source}.
*/
protected int getSourceLength(S source) {
return source.getClass().isArray() ? Array.getLength(source) : ((Collection<?>) source).size();
}
/**
* Sets the {@code element} at the against the {@code destination} at the optional {@code index}.
*/
protected abstract void setElement(D destination, Object element, int index);
}