org.xwiki.properties.internal.DefaultConverterManager Maven / Gradle / Ivy
/*
* See the NOTICE file distributed with this work for additional
* information regarding copyright ownership.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
package org.xwiki.properties.internal;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.lang.reflect.WildcardType;
import javax.inject.Inject;
import javax.inject.Named;
import javax.inject.Provider;
import javax.inject.Singleton;
import org.slf4j.Logger;
import org.xwiki.component.annotation.Component;
import org.xwiki.component.manager.ComponentLookupException;
import org.xwiki.component.manager.ComponentManager;
import org.xwiki.component.util.DefaultParameterizedType;
import org.xwiki.component.util.ReflectionUtils;
import org.xwiki.properties.ConverterManager;
import org.xwiki.properties.converter.ConversionException;
import org.xwiki.properties.converter.Converter;
/**
* Default implementation for {@link ConverterManager}.
*
* It try to find a {@link Converter} for the provided target type. If it can't find:
*
* - if the type is an {@link Enum}, it use the {@link Converter} with component hint "enum"
* - then it use the default {@link Converter} (which is based on {@link org.apache.commons.beanutils.ConvertUtils} by
* default)
*
*
* @version $Id: 57fa124c5660e34d57218e814cc37c0ebc1aa091 $
* @since 2.0M2
*/
@Component
@Singleton
public class DefaultConverterManager implements ConverterManager
{
/**
* Use to find the proper {@link Converter} component for provided target type.
*/
@Inject
@Named("context")
private Provider componentManagerProvider;
/**
* Used when no direct {@link Converter} can be found for provided target type and the target type is an
* {@link Enum}.
*/
@Inject
private Converter enumConverter;
/**
* Used when no direct {@link Converter} can be found for provided target type.
*/
@Inject
private Converter defaultConverter;
/**
* The logger to use for logging.
*/
@Inject
private Logger logger;
@Override
public T convert(Type targetType, Object value)
{
// If the value is already of the right type return it
if (targetType instanceof Class && ((Class) targetType).isInstance(value)) {
return (T) value;
}
// Handle wildcards ()
if (targetType instanceof WildcardType) {
Type[] upperBounds = ((WildcardType) targetType).getUpperBounds();
if (upperBounds.length == 0) {
// If the asked type is , don't convert anything
return (T) value;
} else {
return convert(upperBounds[0], value);
}
}
// Converter type
Type converterType = targetType;
if (converterType == String.class && value != null) {
converterType = value.getClass();
}
// Convert
Converter converter = lookupConverter(converterType);
if (converter != null) {
return converter.convert(targetType, value);
} else {
throw new ConversionException(
"Cannot find Converter to convert value [" + value + "] to type [" + targetType + "] ");
}
}
/**
* Find the right {@link Converter} for the provided {@link Class}.
*
* @param the type in which the provided value has to be converted
* @param targetType the type to convert to
* @return the {@link Converter} corresponding to the class
*/
private Converter lookupConverter(Type targetType)
{
// Try with complete type
Converter converter = getConverter(targetType);
// Try with simple class
if (converter == null && targetType instanceof ParameterizedType) {
Class targetClass = ReflectionUtils.getTypeClass(targetType);
converter = getConverter(targetClass);
}
if (converter == null) {
if (targetType instanceof Class && Enum.class.isAssignableFrom((Class) targetType)) {
// It's an Enum
converter = (Converter) this.enumConverter;
} else {
// Fallback on default converter
this.logger.debug("Using the default Converter for type [{}]", targetType);
converter = this.defaultConverter;
}
}
return converter;
}
@Override
public Converter getConverter(Type targetType)
{
try {
ComponentManager componentManager = this.componentManagerProvider.get();
ParameterizedType converterType = new DefaultParameterizedType(null, Converter.class, targetType);
if (componentManager.hasComponent(converterType)) {
return componentManager.getInstance(converterType);
}
// Old way of registering converters
String typeGenericName = getTypeGenericName(targetType);
if (componentManager.hasComponent(Converter.class, typeGenericName)) {
return componentManager.getInstance(Converter.class, typeGenericName);
}
} catch (ComponentLookupException e) {
throw new ConversionException("Failed to initialize converter for target type [" + targetType + "]", e);
}
return null;
}
/**
* Get class name without generics.
*
* @param type the type
* @return type name without generics
*/
private String getTypeName(Type type)
{
String name;
if (type instanceof Class) {
name = ((Class) type).getName();
} else if (type instanceof ParameterizedType) {
name = ((Class) ((ParameterizedType) type).getRawType()).getName();
} else {
name = type.toString();
}
return name;
}
/**
* Get type name.
*
* @param type the type
* @return type name
*/
private String getTypeGenericName(Type type)
{
StringBuilder sb = new StringBuilder(getTypeName(type));
if (type instanceof ParameterizedType) {
ParameterizedType parameterizedType = (ParameterizedType) type;
Type[] generics = parameterizedType.getActualTypeArguments();
if (generics.length > 0) {
sb.append('<');
for (int i = 0; i < generics.length; ++i) {
if (i > 0) {
sb.append(',');
}
sb.append(getTypeGenericName(generics[i]));
}
sb.append('>');
}
}
return sb.toString();
}
}