Java tutorial
/* * Copyright (C) 2011 Benoit GUEROUT <bguerout at gmail dot com> and Yves AMSELLEM <amsellem dot yves at gmail dot com> * * Licensed 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.jongo; import com.mongodb.DBCollection; import com.mongodb.DBCursor; import com.mongodb.DBObject; import com.mongodb.ReadPreference; import org.jongo.marshall.Unmarshaller; import org.jongo.query.Query; import org.jongo.query.QueryFactory; import java.util.ArrayList; import java.util.List; import static org.jongo.ResultHandlerFactory.newResultHandler; public class Find { private final DBCollection collection; private final ReadPreference readPreference; private final Unmarshaller unmarshaller; private final QueryFactory queryFactory; private final Query query; private final List<QueryModifier> modifiers; private Query fields; Find(DBCollection collection, ReadPreference readPreference, Unmarshaller unmarshaller, QueryFactory queryFactory, String query, Object... parameters) { this.readPreference = readPreference; this.unmarshaller = unmarshaller; this.collection = collection; this.queryFactory = queryFactory; this.query = this.queryFactory.createQuery(query, parameters); this.modifiers = new ArrayList<QueryModifier>(); } public <T> MongoCursor<T> as(final Class<T> clazz) { return map(newResultHandler(clazz, unmarshaller)); } public <T> MongoCursor<T> map(ResultHandler<T> resultHandler) { DBCursor cursor = new DBCursor(collection, query.toDBObject(), getFieldsAsDBObject(), readPreference); for (QueryModifier modifier : modifiers) { modifier.modify(cursor); } return new MongoCursor<T>(cursor, resultHandler); } public Find projection(String fields) { this.fields = queryFactory.createQuery(fields); return this; } public Find projection(String fields, Object... parameters) { this.fields = queryFactory.createQuery(fields, parameters); return this; } public Find limit(final int limit) { this.modifiers.add(new QueryModifier() { public void modify(DBCursor cursor) { cursor.limit(limit); } }); return this; } public Find skip(final int skip) { this.modifiers.add(new QueryModifier() { public void modify(DBCursor cursor) { cursor.skip(skip); } }); return this; } public Find sort(String sort) { final DBObject sortDBObject = queryFactory.createQuery(sort).toDBObject(); this.modifiers.add(new QueryModifier() { public void modify(DBCursor cursor) { cursor.sort(sortDBObject); } }); return this; } public Find hint(String hint) { final DBObject hintDBObject = queryFactory.createQuery(hint).toDBObject(); this.modifiers.add(new QueryModifier() { public void modify(DBCursor cursor) { cursor.hint(hintDBObject); } }); return this; } public Find with(QueryModifier queryModifier) { this.modifiers.add(queryModifier); return this; } private DBObject getFieldsAsDBObject() { return fields == null ? null : fields.toDBObject(); } }