Java tutorial
/* * 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.rya.mongodb.document.operators.query; import static com.google.common.base.Preconditions.checkNotNull; import com.mongodb.BasicDBObject; import com.mongodb.BasicDBObjectBuilder; /** * Utility methods for array operators. */ public final class ArrayOperators { /** * Private constructor to prevent instantiation. */ private ArrayOperators() { } /** * Creates an $size MongoDB expression. * @param expression the expression to get the size of. * @return the $size expression {@link BasicDBObject}. */ public static BasicDBObject size(final Object expression) { final BasicDBObjectBuilder builder = BasicDBObjectBuilder.start(); return (BasicDBObject) size(builder, expression).get(); } /** * Creates an $size MongoDB expression. * @param builder the {@link BasicDBObjectBuilder}. (not {@code null}) * @param expression the expression to get the size of. * @return the $size expression {@link BasicDBObjectBuilder}. */ public static BasicDBObjectBuilder size(final BasicDBObjectBuilder builder, final Object expression) { checkNotNull(builder); builder.add("$size", expression); return builder; } }