/*
* Copyright 2004-2009 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.compass.core.converter.mapping.json;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.compass.core.CompassException;
import org.compass.core.Property;
import org.compass.core.Resource;
import org.compass.core.config.CompassConfigurable;
import org.compass.core.config.CompassEnvironment;
import org.compass.core.config.CompassSettings;
import org.compass.core.config.ConfigurationException;
import org.compass.core.converter.ConversionException;
import org.compass.core.converter.Converter;
import org.compass.core.converter.json.JsonContentConverter;
import org.compass.core.json.JsonObject;
import org.compass.core.json.impl.converter.DefaultJSONContentConverterImpl;
import org.compass.core.mapping.Mapping;
import org.compass.core.mapping.json.JsonContentMapping;
import org.compass.core.marshall.MarshallingContext;
import org.compass.core.util.ClassUtils;
/**
* @author kimchy
*/
public class JsonContentMappingConverter implements Converter, CompassConfigurable {
private static final Log log = LogFactory.getLog(JsonContentMappingConverter.class);
private JsonContentConverter contentConverter;
public void configure(CompassSettings settings) throws CompassException {
String type = settings.getGloablSettings().getSetting(CompassEnvironment.Jsem.JsonContent.TYPE);
if (type == null) {
type = DefaultJSONContentConverterImpl.class.getName();
}
if (log.isDebugEnabled()) {
log.debug("Usign Json content converter [" + type + "]");
}
try {
contentConverter = (JsonContentConverter) ClassUtils.forName(type, settings.getClassLoader()).newInstance();
} catch (Exception e) {
throw new ConfigurationException("Failed to create jsonContent [" + type + "]", e);
}
if (contentConverter instanceof CompassConfigurable) {
((CompassConfigurable) contentConverter).configure(settings);
}
}
public JsonContentConverter getContentConverter() {
return contentConverter;
}
public boolean marshall(Resource resource, Object root, Mapping mapping, MarshallingContext context) throws ConversionException {
// don't save a null value if the context does not states so
if (root == null && !handleNulls(context)) {
return false;
}
JsonContentMapping jsonContentMapping = (JsonContentMapping) mapping;
String sValue;
if (root instanceof String) {
sValue = (String) root;
} else {
JsonObject jsonObject = (JsonObject) root;
sValue = contentConverter.toJSON(jsonObject);
}
String propertyName = jsonContentMapping.getPath().getPath();
Property p = context.getResourceFactory().createProperty(propertyName, sValue, jsonContentMapping);
resource.addProperty(p);
return jsonContentMapping.getStore() != Property.Store.NO;
}
public Object unmarshall(Resource resource, Mapping mapping, MarshallingContext context) throws ConversionException {
JsonContentMapping jsonContentMapping = (JsonContentMapping) mapping;
String propertyName = jsonContentMapping.getPath().getPath();
Property p = resource.getProperty(propertyName);
// don't set anything if null
if (p == null || isNullValue(context, p.getStringValue())) {
return null;
}
return contentConverter.fromJSON(resource.getAlias(), p.getStringValue());
}
/**
* Should the converter handle nulls? Handling nulls means should the
* converter process nulls or not. Usually the converter will not
* persist null values, but sometimes it might be needed
* ({@link org.compass.core.marshall.MarshallingContext#handleNulls()}).
*
* <p>Extracted to a method so special converters can control null handling.
*
* @param context The marshalling context
* @return <code>true</code> if the converter should handle null values
*/
protected boolean handleNulls(MarshallingContext context) {
return context.handleNulls();
}
/**
* Is the value read from the search engine is a <code>null</code> value
* during the unmarshall process.
*
* @param context The marshalling context
* @param value The value to check for <code>null</code> value.
* @return <code>true</code> if the value represents a null value.
*/
protected boolean isNullValue(MarshallingContext context, String value) {
return context.getResourceFactory().isNullValue(value);
}
}