/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF 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
* <p/>
* http://www.apache.org/licenses/LICENSE-2.0
* <p/>
* 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.apache.ambari.view.hive2.resources.uploads.parsers.xml;
import org.apache.ambari.view.hive2.client.Row;
import org.apache.ambari.view.hive2.resources.uploads.parsers.ParseOptions;
import org.apache.ambari.view.hive2.resources.uploads.parsers.Parser;
import org.apache.ambari.view.hive2.resources.uploads.parsers.RowIterator;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import javax.xml.stream.XMLEventReader;
import javax.xml.stream.XMLInputFactory;
import javax.xml.stream.XMLStreamException;
import java.io.IOException;
import java.io.Reader;
import java.util.Collection;
import java.util.Iterator;
/**
* assumes XML of following format
* <table>
* <row>
* <col name="col1Name">row1-col1-Data</col>
* <col name="col2Name">row1-col2-Data</col>
* <col name="col3Name">row1-col3-Data</col>
* <col name="col4Name">row1-col4-Data</col>
* </row>
* <row>
* <col name="col1Name">row2-col1-Data</col>
* <col name="col2Name">row2-col2-Data</col>
* <col name="col3Name">row2-col3-Data</col>
* <col name="col4Name">row2-col4-Data</col>
* </row>
* </table>
*/
public class XMLParser extends Parser {
protected final static Logger LOG =
LoggerFactory.getLogger(XMLParser.class);
private RowIterator iterator;
private XMLEventReader xmlReader;
private XMLIterator xmlIterator;
public XMLParser(Reader reader, ParseOptions parseOptions) throws IOException {
super(reader, parseOptions);
XMLInputFactory factory = XMLInputFactory.newInstance();
try {
factory.setProperty(XMLInputFactory.SUPPORT_DTD, false);
factory.setProperty(XMLInputFactory.IS_SUPPORTING_EXTERNAL_ENTITIES, false);
this.xmlReader = factory.createXMLEventReader(reader);
} catch (XMLStreamException e) {
LOG.error("error occurred while creating xml reader : ", e);
throw new IOException("error occurred while creating xml reader : ", e);
}
xmlIterator = new XMLIterator(this.xmlReader);
iterator = new RowIterator(xmlIterator);
}
@Override
public Row extractHeader() {
Collection<String> headers = this.iterator.extractHeaders();
Object[] objs = new Object[headers.size()];
Iterator<String> iterator = headers.iterator();
for (int i = 0; i < headers.size(); i++) {
objs[i] = iterator.next();
}
return new Row(objs);
}
@Override
public void close() throws Exception {
try {
this.xmlReader.close();
} catch (XMLStreamException e) {
throw new IOException(e);
}
}
@Override
public Iterator<Row> iterator() {
return iterator;
}
}