/* * 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.GroupCommand; 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_MONGODB_CLIENT; 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.FunctionParameterSequenceType; 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 Group extends BasicFunction { private static final String GROUP = "group"; public static final FunctionParameterSequenceType PARAMETER_KEY = new FunctionParameterSequenceType("key", Type.STRING, Cardinality.ONE, "Specifies one or more document fields to group. JSON formatted."); public static final FunctionParameterSequenceType PARAMETER_COND = new FunctionParameterSequenceType("cond", Type.STRING, Cardinality.ONE, "Specifies the selection criteria to determine which documents in the collection to process. JSON formatted."); public static final FunctionParameterSequenceType PARAMETER_INITIAL = new FunctionParameterSequenceType("initial", Type.STRING, Cardinality.ONE, "Initializes the aggregation result document. JSON formatted."); public static final FunctionParameterSequenceType PARAMETER_REDUCE = new FunctionParameterSequenceType("reduce", Type.STRING, Cardinality.ONE, "Specifies an $reduce Javascript function, that operates on the documents during the grouping operation."); public static final FunctionParameterSequenceType PARAMETER_FINALIZE = new FunctionParameterSequenceType("finalize", Type.STRING, Cardinality.ONE, "Specifies a Javascript function that runs each item in the result set before final value will be returned."); private static final String DESCRIPTION = "Group documents in a collection by the specified key and performs " + "simple aggregation functions such as computing counts and sums. This is analogous to a SELECT ... GROUP BY statement in SQL."; private static final String RESULT = "A document with the grouped records as well as the command meta-data formatted as JSON"; public final static FunctionSignature signatures[] = { new FunctionSignature( new QName(GROUP, MongodbModule.NAMESPACE_URI, MongodbModule.PREFIX), DESCRIPTION, new SequenceType[]{ PARAMETER_MONGODB_CLIENT, PARAMETER_DATABASE, PARAMETER_COLLECTION, PARAMETER_KEY, PARAMETER_COND, PARAMETER_INITIAL, PARAMETER_REDUCE}, new FunctionReturnSequenceType(Type.STRING, Cardinality.ONE, RESULT) ), new FunctionSignature( new QName(GROUP, MongodbModule.NAMESPACE_URI, MongodbModule.PREFIX), DESCRIPTION, new SequenceType[]{ PARAMETER_MONGODB_CLIENT, PARAMETER_DATABASE, PARAMETER_COLLECTION, PARAMETER_KEY, PARAMETER_COND, PARAMETER_INITIAL, PARAMETER_REDUCE, PARAMETER_FINALIZE}, new FunctionReturnSequenceType(Type.STRING, Cardinality.ONE, RESULT) ) }; public Group(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 key = (BasicDBObject) JSON.parse(args[3].itemAt(0).getStringValue()); BasicDBObject condition = (BasicDBObject) JSON.parse(args[4].itemAt(0).getStringValue()); BasicDBObject initial = (BasicDBObject) JSON.parse(args[5].itemAt(0).getStringValue()); String reduce = args[6].itemAt(0).getStringValue(); // The finalize can be null String finalize = (args.length >= 8) ? args[7].itemAt(0).getStringValue() : null; // Get database DB db = client.getDB(dbname); DBCollection dbcol = db.getCollection(collection); // Propare groupcommand GroupCommand command = new GroupCommand(dbcol, key, condition, initial, reduce, finalize); System.out.println(command.toDBObject().toString()); if(LOG.isDebugEnabled()){ LOG.debug(command.toDBObject().toString()); } // Execute, finalize can have value null DBObject result = dbcol.group(command); // Execute query Sequence retVal = 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()); } } }