org.n52.svalbard.read.NillableReader Maven / Gradle / Ivy
/*
* Copyright 2016-2017 52°North Initiative for Geospatial Open Source
* Software GmbH
*
* 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.n52.svalbard.read;
import java.util.Arrays;
import java.util.List;
import javax.xml.namespace.QName;
import javax.xml.stream.XMLStreamException;
import org.n52.shetland.aqd.AqdConstants;
import org.n52.shetland.iso.GcoConstants;
import org.n52.shetland.w3c.Nillable;
import org.n52.shetland.w3c.W3CConstants;
import org.n52.svalbard.decode.exception.DecodingException;
import com.google.common.base.Optional;
import com.google.common.collect.Iterables;
/**
* TODO JavaDoc
*
* @author Christian Autermann
*/
public abstract class NillableReader extends XmlReader> {
private Nillable nillable;
protected abstract XmlReader getDelegate();
protected List getPossibleNilReasonAttributes() {
return Arrays.asList(AqdConstants.QN_NIL_REASON,
GcoConstants.QN_GCO_NIL_REASON);
}
@Override
protected void begin()
throws XMLStreamException, DecodingException {
Optional attr = attr(W3CConstants.QN_XSI_NIL);
if (attr.isPresent() && attr.get().equals("true")) {
List attributeNames = getPossibleNilReasonAttributes();
Iterable> attributes = attr(attributeNames);
Iterable reasons = Optional.presentInstances(attributes);
this.nillable = Nillable.nil(Iterables.getFirst(reasons, null));
} else {
this.nillable = Nillable.of(delegate(getDelegate()));
}
}
@Override
protected Nillable finish() {
return nillable;
}
}