/*
* eXist Open Source Native XML Database
* Copyright (C) 2014 The eXist Project
* http://exist-db.org
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* 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 library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
package org.exist.mongodb.xquery.mongodb.collection;
import com.mongodb.BasicDBObject;
import com.mongodb.DB;
import com.mongodb.DBCollection;
import com.mongodb.DBObject;
import com.mongodb.MongoClient;
import com.mongodb.MongoException;
import com.mongodb.util.JSON;
import com.mongodb.util.JSONParseException;
import org.exist.dom.QName;
import static org.exist.mongodb.shared.FunctionDefinitions.PARAMETER_COLLECTION;
import static org.exist.mongodb.shared.FunctionDefinitions.PARAMETER_DATABASE;
import static org.exist.mongodb.shared.FunctionDefinitions.PARAMETER_FIELDS;
import static org.exist.mongodb.shared.FunctionDefinitions.PARAMETER_MONGODB_CLIENT;
import static org.exist.mongodb.shared.FunctionDefinitions.PARAMETER_ORDERBY;
import static org.exist.mongodb.shared.FunctionDefinitions.PARAMETER_QUERY;
import org.exist.mongodb.shared.MongodbClientStore;
import org.exist.mongodb.xquery.MongodbModule;
import org.exist.xquery.BasicFunction;
import org.exist.xquery.Cardinality;
import org.exist.xquery.FunctionSignature;
import org.exist.xquery.XPathException;
import org.exist.xquery.XQueryContext;
import org.exist.xquery.value.FunctionReturnSequenceType;
import org.exist.xquery.value.Sequence;
import org.exist.xquery.value.SequenceType;
import org.exist.xquery.value.StringValue;
import org.exist.xquery.value.Type;
/**
* Functions to retrieve documents from GridFS as a stream.
*
* @author Dannes Wessels
*/
public class FindOne extends BasicFunction {
private static final String FIND_ONE = "findOne";
public final static FunctionSignature signatures[] = {
new FunctionSignature(
new QName(FIND_ONE, MongodbModule.NAMESPACE_URI, MongodbModule.PREFIX), "Retrieve a single object from this collection.",
new SequenceType[]{
PARAMETER_MONGODB_CLIENT, PARAMETER_DATABASE, PARAMETER_COLLECTION},
new FunctionReturnSequenceType(Type.STRING, Cardinality.ZERO_OR_ONE, "The object formatted as JSON")
),
new FunctionSignature(
new QName(FIND_ONE, MongodbModule.NAMESPACE_URI, MongodbModule.PREFIX), "Retrieve a single object from this collection matching the query.",
new SequenceType[]{
PARAMETER_MONGODB_CLIENT, PARAMETER_DATABASE, PARAMETER_COLLECTION, PARAMETER_QUERY},
new FunctionReturnSequenceType(Type.STRING, Cardinality.ZERO_OR_ONE, "The object formatted as JSON")
),
new FunctionSignature(
new QName(FIND_ONE, MongodbModule.NAMESPACE_URI, MongodbModule.PREFIX), "Retrieve a single object from this collection matching the query.",
new SequenceType[]{
PARAMETER_MONGODB_CLIENT, PARAMETER_DATABASE, PARAMETER_COLLECTION, PARAMETER_QUERY, PARAMETER_FIELDS},
new FunctionReturnSequenceType(Type.STRING, Cardinality.ZERO_OR_ONE, "The object formatted as JSON")
),
new FunctionSignature(
new QName(FIND_ONE, MongodbModule.NAMESPACE_URI, MongodbModule.PREFIX), "Returns a single object from this collection matching the query.",
new SequenceType[]{
PARAMETER_MONGODB_CLIENT, PARAMETER_DATABASE, PARAMETER_COLLECTION, PARAMETER_QUERY,PARAMETER_FIELDS, PARAMETER_ORDERBY},
new FunctionReturnSequenceType(Type.STRING, Cardinality.ZERO_OR_ONE, "The object formatted as JSON")
),
};
public FindOne(XQueryContext context, FunctionSignature signature) {
super(context, signature);
}
@Override
public Sequence eval(Sequence[] args, Sequence contextSequence) throws XPathException {
try {
// Verify clientid and get client
String mongodbClientId = args[0].itemAt(0).getStringValue();
MongodbClientStore.getInstance().validate(mongodbClientId);
MongoClient client = MongodbClientStore.getInstance().get(mongodbClientId);
// Get parameters
String dbname = args[1].itemAt(0).getStringValue();
String collection = args[2].itemAt(0).getStringValue();
BasicDBObject query = (args.length >= 4)
? (BasicDBObject) JSON.parse(args[3].itemAt(0).getStringValue())
: null;
BasicDBObject fields = (args.length >= 5)
? (BasicDBObject) JSON.parse(args[4].itemAt(0).getStringValue())
: null;
BasicDBObject orderBy = (args.length >= 6)
? (BasicDBObject) JSON.parse(args[5].itemAt(0).getStringValue())
: null;
// Check id
MongodbClientStore.getInstance().validate(mongodbClientId);
// Get database
DB db = client.getDB(dbname);
DBCollection dbcol = db.getCollection(collection);
DBObject result;
if (fields == null && orderBy == null && query == null) {
result = dbcol.findOne();
} else if (fields == null && orderBy == null) {
result = dbcol.findOne(query);
} else if (orderBy == null) {
result = dbcol.findOne(query, fields);
} else {
result = dbcol.findOne(query, fields, orderBy);
}
// Execute query
Sequence retVal = (result==null)
? Sequence.EMPTY_SEQUENCE
: new StringValue(result.toString());
return retVal;
} catch(JSONParseException ex){
LOG.error(ex.getMessage());
throw new XPathException(this, MongodbModule.MONG0004, ex.getMessage());
} catch (XPathException ex) {
LOG.error(ex.getMessage(), ex);
throw new XPathException(this, ex.getMessage(), ex);
} catch (MongoException ex) {
LOG.error(ex.getMessage(), ex);
throw new XPathException(this, MongodbModule.MONG0002, ex.getMessage());
} catch (Throwable ex) {
LOG.error(ex.getMessage(), ex);
throw new XPathException(this, MongodbModule.MONG0003, ex.getMessage());
}
}
}