/**
* 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
*
* 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.apache.metamodel.couchdb;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import org.codehaus.jackson.JsonNode;
import org.codehaus.jackson.map.ObjectMapper;
import org.ektorp.StreamingViewResult;
import org.apache.metamodel.data.AbstractDataSet;
import org.apache.metamodel.data.DefaultRow;
import org.apache.metamodel.data.Row;
import org.apache.metamodel.query.SelectItem;
/**
* DataSet implementation for couch db.
*/
final class CouchDbDataSet extends AbstractDataSet {
private final Iterator<org.ektorp.ViewResult.Row> _iterator;
private final StreamingViewResult _streamingViewResult;
private DefaultRow _row;
public CouchDbDataSet(SelectItem[] selectItems, StreamingViewResult streamingViewResult) {
super(selectItems);
_streamingViewResult = streamingViewResult;
_iterator = _streamingViewResult.iterator();
}
@Override
public boolean next() {
if (_iterator == null || !_iterator.hasNext()) {
return false;
}
final org.ektorp.ViewResult.Row row = _iterator.next();
final JsonNode node = row.getDocAsNode();
final int size = getHeader().size();
final Object[] values = new Object[size];
for (int i = 0; i < size; i++) {
final String key = getHeader().getSelectItem(i).getColumn().getName();
final JsonNode valueNode = node.get(key);
final Object value;
if (valueNode == null || valueNode.isNull()) {
value = null;
} else if (valueNode.isTextual()) {
value = valueNode.asText();
} else if (valueNode.isArray()) {
value = toList(valueNode);
} else if (valueNode.isObject()) {
value = toMap(valueNode);
} else if (valueNode.isBoolean()) {
value = valueNode.asBoolean();
} else if (valueNode.isInt()) {
value = valueNode.asInt();
} else if (valueNode.isLong()) {
value = valueNode.asLong();
} else if (valueNode.isDouble()) {
value = valueNode.asDouble();
} else {
value = valueNode;
}
values[i] = value;
}
_row = new DefaultRow(getHeader(), values);
return true;
}
private Map<String, Object> toMap(JsonNode valueNode) {
if (valueNode == null) {
return null;
}
try {
return new ObjectMapper().reader(Map.class).readValue(valueNode);
} catch (Exception e) {
throw new IllegalStateException(e);
}
}
private Object toList(JsonNode valueNode) {
if (valueNode == null) {
return null;
}
try {
return new ObjectMapper().reader(List.class).readValue(valueNode);
} catch (Exception e) {
throw new IllegalStateException(e);
}
}
@Override
public Row getRow() {
return _row;
}
@Override
public void close() {
super.close();
_streamingViewResult.close();
}
}