Java tutorial
/* * Copyright 2011-2019 the original author or authors. * * 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 * * https://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.springframework.data.mongodb.gridfs; import org.springframework.data.mongodb.core.query.Criteria; import org.springframework.lang.Nullable; /** * GridFs-specific helper class to define {@link Criteria}s. * * @author Oliver Gierke * @author Christoph Strobl */ public class GridFsCriteria extends Criteria { /** * Creates a new {@link GridFsCriteria} for the given key. * * @param key */ public GridFsCriteria(String key) { super(key); } /** * Creates a {@link GridFsCriteria} for restrictions on the file's metadata. * * @return */ public static GridFsCriteria whereMetaData() { return new GridFsCriteria("metadata"); } /** * Creates a {@link GridFsCriteria} for restrictions on a single file's metadata item. * * @param metadataKey * @return */ public static GridFsCriteria whereMetaData(@Nullable String metadataKey) { String extension = metadataKey == null ? "" : "." + metadataKey; return new GridFsCriteria(String.format("metadata%s", extension)); } /** * Creates a {@link GridFsCriteria} for restrictions on the file's name. * * @return */ public static GridFsCriteria whereFilename() { return new GridFsCriteria("filename"); } /** * Creates a {@link GridFsCriteria} for restrictions on the file's content type. * * @return */ public static GridFsCriteria whereContentType() { return new GridFsCriteria("metadata.".concat(GridFsResource.CONTENT_TYPE_FIELD)); } }