/**
* 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;
import org.apache.ambari.view.hive2.client.Row;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.LinkedList;
/**
* Converts the Map of values created by JSON/XML Parser into ordered values in Row
* Takes RowMapIterator as input
*/
public class RowIterator implements Iterator<Row> {
private LinkedList<String> headers = null;
private RowMapIterator iterator;
/**
* creates a row iterator for the map values in RowMapIterator
* keeps the keys in map as header.
* @param iterator
*/
public RowIterator(RowMapIterator iterator) {
this.iterator = iterator;
LinkedHashMap<String, String> obj = iterator.peek();
headers = new LinkedList<>();
if (null != obj) {
headers.addAll(obj.keySet());
}
}
@Override
public boolean hasNext() {
return iterator.hasNext();
}
@Override
public Row next() {
LinkedHashMap<String, String> r = this.iterator.next();
if (null == r) {
return null;
}
return convertToRow(r);
}
@Override
public void remove() {
iterator.remove();
}
/**
* @return : ordered collection of string of headers
*/
public LinkedList<String> extractHeaders() {
return headers;
}
/**
* converts the map into a Row
* @param lr
* @return
*/
private Row convertToRow(LinkedHashMap<String, String> lr) {
Object[] data = new Object[headers.size()];
int i = 0;
for (String cd : headers) {
String d = lr.get(cd);
if (d != null)
d = d.trim(); // trim to remove any \n etc which is used as a separator for rows in TableDataReader
data[i++] = d;
}
return new Row(data);
}
}