
org.eobjects.metamodel.couchdb.CouchDbDataSet Maven / Gradle / Ivy
/**
* eobjects.org MetaModel
* Copyright (C) 2010 eobjects.org
*
* This copyrighted material is made available to anyone wishing to use, modify,
* copy, or redistribute it subject to the terms and conditions of the GNU
* Lesser General Public License, as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
* for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this distribution; if not, write to:
* Free Software Foundation, Inc.
* 51 Franklin Street, Fifth Floor
* Boston, MA 02110-1301 USA
*/
package org.eobjects.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.eobjects.metamodel.data.AbstractDataSet;
import org.eobjects.metamodel.data.DefaultRow;
import org.eobjects.metamodel.data.Row;
import org.eobjects.metamodel.query.SelectItem;
/**
* DataSet implementation for couch db.
*/
final class CouchDbDataSet extends AbstractDataSet {
private final Iterator _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 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();
}
}
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