/*
* Copyright 2013 Esri.
*
* 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 com.esri.gpt.control.webharvest.client.dcat;
import com.esri.gpt.catalog.harvest.protocols.HarvestProtocolDCAT;
import com.esri.gpt.control.webharvest.IterationContext;
import com.esri.gpt.control.webharvest.common.CommonCapabilities;
import com.esri.gpt.framework.dcat.DcatParser;
import com.esri.gpt.framework.dcat.DcatParserAdaptor;
import com.esri.gpt.framework.resource.api.Native;
import com.esri.gpt.framework.resource.api.Publishable;
import com.esri.gpt.framework.resource.api.SourceUri;
import com.esri.gpt.framework.resource.common.CommonPublishable;
import com.esri.gpt.framework.resource.common.UrlUri;
import com.esri.gpt.framework.resource.query.Capabilities;
import com.esri.gpt.framework.resource.query.Criteria;
import com.esri.gpt.framework.resource.query.Query;
import com.esri.gpt.framework.resource.query.QueryBuilder;
import java.io.IOException;
import java.net.URL;
import java.util.Iterator;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.xml.transform.TransformerException;
/**
* DCAT query builder.
*/
public class DCATQueryBuilder implements QueryBuilder {
/** logger */
private static final Logger LOGGER = Logger.getLogger(DCATQuery.class.getCanonicalName());
/** capabilities */
private static final Capabilities capabilities = new DCATCommonCapabilities();
/** iteration context */
private IterationContext context;
/** service info */
private DCATInfo info;
/**
* Creates instance of the builder.
* @param context iteration context
* @param protocol protocol
* @param url URL
*/
public DCATQueryBuilder(IterationContext context, HarvestProtocolDCAT protocol, String url) {
if (context == null) {
throw new IllegalArgumentException("No context provided.");
}
this.context = context;
this.info = new DCATInfo(url,protocol.getFormat());
}
@Override
public Capabilities getCapabilities() {
return capabilities;
}
@Override
public Query newQuery(Criteria crt) {
Query q = new DCATQuery(context, info, crt);
LOGGER.log(Level.FINER, "Query created: {0}", q);
return q;
}
@Override
public Native getNativeResource() {
DCATIteratorAdaptor adaptor = null;
try {
URL url = new URL(info.getUrl());
adaptor = new DCATIteratorAdaptor(info.getFormat(), new DcatParserAdaptor(new DcatParser(url.openStream())));
Iterator<Publishable> iterator = adaptor.iterator();
if (iterator.hasNext()) {
return new NativeImpl(iterator.next().getContent());
}
} catch (Exception ex) {
LOGGER.log(Level.WARNING, "Error reading native resource.", ex);
} finally {
if (adaptor!=null) {
adaptor.close();
}
}
return null;
}
/**
* Native implementation.
*/
private class NativeImpl extends CommonPublishable implements Native {
private String content;
public NativeImpl(String content) {
this.content = content;
}
@Override
public SourceUri getSourceUri() {
return new UrlUri(info.getUrl());
}
@Override
public String getContent() throws IOException {
return content;
}
}
/**
* DCAT capabilities.
*/
private static class DCATCommonCapabilities extends CommonCapabilities {
@Override
public boolean canQueryFromDate() {
return true;
}
@Override
public boolean canQueryToDate() {
return true;
}
}
}