/*
* Copyright (c) 2005-2010, WSO2 Inc. (http://www.wso2.org) All Rights Reserved.
*
* WSO2 Inc. licenses this file to you 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.wso2.carbon.dataservices.core.description.query;
import org.apache.axiom.om.OMElement;
import org.apache.axiom.om.util.AXIOMUtil;
import org.apache.log4j.Logger;
import org.webharvest.runtime.variables.Variable;
import org.wso2.carbon.dataservices.core.DataServiceFault;
import org.wso2.carbon.dataservices.core.description.config.WebConfig;
import org.wso2.carbon.dataservices.core.description.event.EventTrigger;
import org.wso2.carbon.dataservices.core.engine.DataEntry;
import org.wso2.carbon.dataservices.core.engine.DataService;
import org.wso2.carbon.dataservices.core.engine.InternalParamCollection;
import org.wso2.carbon.dataservices.core.engine.ParamValue;
import org.wso2.carbon.dataservices.core.engine.PrefetchDataInfo;
import org.wso2.carbon.dataservices.core.engine.QueryParam;
import org.wso2.carbon.dataservices.core.engine.Result;
import javax.xml.stream.XMLStreamWriter;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
/**
* This class represents a Web query in a data service.
*/
public class WebQuery extends Query {
private WebConfig config;
private String scraperVariable;
private static Logger log = Logger.getLogger(WebQuery.class);
public WebQuery(DataService dataService, String queryId,
List<QueryParam> queryParams, String configId, Result result,
EventTrigger inputEventTrigger, EventTrigger outputEventTrigger,
Map<String, String> advancedProperties, String scraperVariable,
String inputNamespace)
throws DataServiceFault {
super(dataService, queryId, queryParams, result, configId,
inputEventTrigger, outputEventTrigger, advancedProperties, inputNamespace);
try {
this.config = (WebConfig) this.getDataService().getConfig(this.getConfigId());
} catch (ClassCastException e) {
throw new DataServiceFault(e, "Configuration is not an Web config:"
+ this.getConfigId());
}
this.scraperVariable = scraperVariable;
}
public WebConfig getConfig() {
return config;
}
public String getScraperVariable() {
return scraperVariable;
}
@SuppressWarnings("unchecked")
public PrefetchDataInfo runQuery(XMLStreamWriter xmlWriter, InternalParamCollection params,
int queryLevel, boolean prefetchData,
PrefetchDataInfo prefetchedData)
throws DataServiceFault {
if (prefetchData) {
return null;
}
Variable scrapedOutput = this.getConfig().getScrapedResult(getScraperVariable());
try {
OMElement resultEl = AXIOMUtil.stringToOM(scrapedOutput.toString());
OMElement entryEl, fieldEl;
DataEntry dataEntry;
boolean useColumnNumbers = this.isUsingColumnNumbers();
int i;
for (Iterator<OMElement> recordItr = resultEl.getChildElements(); recordItr.hasNext();) {
entryEl = recordItr.next();
dataEntry = new DataEntry();
i = 1;
for (Iterator<OMElement> fieldItr = entryEl.getChildElements(); fieldItr.hasNext();) {
fieldEl = fieldItr.next();
dataEntry.addValue(useColumnNumbers ? Integer.toString(i) :
fieldEl.getLocalName(), new ParamValue(fieldEl.getText()));
i++;
}
this.writeResultEntry(xmlWriter, dataEntry, params, queryLevel);
}
return null;
} catch (Exception e) {
log.error("Error in executing web scraping query", e);
throw new DataServiceFault(e);
}
}
}