/*
* 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.json;
import org.compass.core.Property;
import org.compass.core.Resource;
import org.compass.core.converter.ConversionException;
import org.compass.core.converter.Converter;
import org.compass.core.converter.mapping.ResourcePropertyConverter;
import org.compass.core.converter.mapping.json.AbstractDynamicJsonMappingConverter;
import org.compass.core.engine.naming.PropertyPath;
import org.compass.core.mapping.Mapping;
import org.compass.core.mapping.ResourcePropertyMapping;
import org.compass.core.mapping.json.JsonPropertyMapping;
import org.compass.core.mapping.json.Naming;
import org.compass.core.marshall.MarshallingContext;
/**
* A simple JSON value converter that supports marshalling. Uses built in registed converters for types such
* as int, float and String.
*
* @author kimchy
*/
public class SimpleJsonValueConverter implements Converter {
/**
* Marshals the given object value into a {@link org.compass.core.Property} which is added to the provided
* {@link org.compass.core.Resource}.
*
* <p>Handles null values based on the given null value mappings by calling {@link #getNullValue(org.compass.core.mapping.ResourcePropertyMapping, org.compass.core.marshall.MarshallingContext)}.
*
* <p>The value itself is converted from an Object to a String using {@link #toString(Object, org.compass.core.mapping.ResourcePropertyMapping, org.compass.core.marshall.MarshallingContext)}.
*/
public boolean marshall(Resource resource, Object root, Mapping mapping, MarshallingContext context) throws ConversionException {
JsonPropertyMapping jsonPropertyMapping = (JsonPropertyMapping) mapping;
// don't save a null value if the context does not states so
if (root == null && !handleNulls(jsonPropertyMapping, context)) {
return false;
}
String sValue = getNullValue(jsonPropertyMapping, context);
if (root != null) {
sValue = toString(root, jsonPropertyMapping, context);
}
String propertyName;
if (jsonPropertyMapping.isDynamic()) {
Naming dynamicNaming = (Naming) context.getAttribute(AbstractDynamicJsonMappingConverter.DYNAMIC_NAMING);
if (dynamicNaming != null && dynamicNaming == Naming.FULL) {
propertyName = ((JsonFullPathHolder) context.getAttribute(JsonFullPathHolder.CONTEXT_KEY)).calculatePath();
} else {
PropertyPath path = jsonPropertyMapping.getPath();
if (path == null) {
propertyName = (String) context.getAttribute(AbstractDynamicJsonMappingConverter.DYNAMIC_PATH_CONTEXT_KEY);
} else {
propertyName = path.getPath();
}
}
} else {
if (jsonPropertyMapping.getNamingType() == Naming.FULL) {
propertyName = ((JsonFullPathHolder) context.getAttribute(JsonFullPathHolder.CONTEXT_KEY)).calculatePath();
} else {
PropertyPath path = jsonPropertyMapping.getPath();
if (path == null) {
propertyName = (String) context.getAttribute(AbstractDynamicJsonMappingConverter.DYNAMIC_PATH_CONTEXT_KEY);
} else {
propertyName = path.getPath();
}
}
}
Property property;
if (jsonPropertyMapping.isDynamic() && root != null) {
ResourcePropertyConverter converter = (ResourcePropertyConverter) context.getConverterLookup().lookupConverter(root.getClass());
property = context.getResourceFactory().createProperty(propertyName, sValue, converter);
} else {
property = context.getResourceFactory().createProperty(propertyName, sValue, jsonPropertyMapping);
}
doSetBoost(property, root, jsonPropertyMapping, context);
resource.addProperty(property);
return jsonPropertyMapping.getStore() != Property.Store.NO;
}
/**
* <p>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>If a specific null value is configured with the {@link org.compass.core.mapping.ResourcePropertyMapping}
* then the converter will always handle nulls and write it.
*
* @param context The marshalling context
* @return <code>true</code> if the converter should handle null values
*/
protected boolean handleNulls(ResourcePropertyMapping resourcePropertyMapping, MarshallingContext context) {
return resourcePropertyMapping.hasNullValue() || context.handleNulls();
}
/**
* If the converter handle nulls, the value that will be stored in the
* search engine for <code>null</code> values (during the marshall process). Uses
* {@link org.compass.core.mapping.ResourcePropertyMapping#getNullValue()}.
*
* @param resourcePropertyMapping The resource proeprty mapping to get the null value from
* @param context The marshalling context
* @return Null value that will be inserted for <code>null</code>s.
*/
protected String getNullValue(ResourcePropertyMapping resourcePropertyMapping, MarshallingContext context) {
return resourcePropertyMapping.getNullValue();
}
/**
* A simple extension point that allows to set the boost value for the created {@link org.compass.core.Property}.
*
* <p>The default implemenation uses the statically defined boost value in the mapping definition
* ({@link org.compass.core.mapping.ResourcePropertyMapping#getBoost()}) to set the boost level
* using {@link org.compass.core.Property#setBoost(float)}
*
* @param property The property to set the boost on
* @param root The object that is marshalled into a property
* @param resourcePropertyMapping The Resource Property Mapping definition
* @throws org.compass.core.converter.ConversionException
*
*/
protected void doSetBoost(Property property, Object root, ResourcePropertyMapping resourcePropertyMapping,
MarshallingContext context) throws ConversionException {
property.setBoost(resourcePropertyMapping.getBoost());
}
/**
* Converst a value to a String. Tryies to infer based on the type and use one of the registered converters
* based on the given type (in JSON we can have double, int, as well as Strings). Uses
* {@link org.compass.core.converter.ConverterLookup#lookupConverter(Class)}.
*
* <p>The resulting converter is then used and uses {@link org.compass.core.converter.mapping.ResourcePropertyConverter#toString(Object, org.compass.core.mapping.ResourcePropertyMapping)}.
*/
protected String toString(Object value, ResourcePropertyMapping resourcePropertyMapping, MarshallingContext context) {
ResourcePropertyConverter converter = (ResourcePropertyConverter) context.getConverterLookup().lookupConverter(value.getClass());
return converter.toString(value, resourcePropertyMapping);
}
/**
* Not supported operation.
*/
public Object unmarshall(Resource resource, Mapping mapping, MarshallingContext context) throws ConversionException {
throw new ConversionException("Not supported");
}
}