Java tutorial
/* * Copyright 2014-2016 CyberVision, Inc. * * 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.kaaproject.kaa.server.common.dao.model.sql; import static org.apache.commons.lang.StringUtils.isNotBlank; import org.apache.commons.io.IOUtils; import org.kaaproject.kaa.common.dto.HasId; import org.kaaproject.kaa.common.dto.TopicDto; import org.kaaproject.kaa.server.common.dao.model.ToDto; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import java.io.IOException; import java.io.InputStream; import java.io.UnsupportedEncodingException; import java.nio.charset.Charset; import java.util.ArrayList; import java.util.Arrays; import java.util.Collection; import java.util.Collections; import java.util.HashSet; import java.util.List; import java.util.Set; public class ModelUtils { public static final String UTF8 = "UTF-8"; private static final Logger LOG = LoggerFactory.getLogger(ModelUtils.class); private ModelUtils() { throw new UnsupportedOperationException("Not supported"); } public static String getStringId(Long longId) { return longId != null ? longId.toString() : null; } /** * Get string id. * * @param hasId the object that has id * @return id */ public static String getStringId(GenericModel<?> hasId) { String stringId = null; if (hasId != null) { Long id = hasId.getId(); stringId = getStringId(id); } return stringId; } /** * Get Long id from object with id. * * @param hasId the object with id * @return id */ public static Long getLongId(HasId hasId) { Long longId = null; if (hasId != null) { String id = hasId.getId(); longId = getLongId(id); } return longId; } /** * Get Long id from string. * * @param id the id string * @return Long id */ public static Long getLongId(String id) { Long longId = null; if (isNotBlank(id)) { try { longId = Long.valueOf(id); } catch (NumberFormatException ex) { LOG.error("Can't convert to Long id. Incorrect String id {} ", id); } } return longId; } /** * Get topics by ids. * * @param topicIds the List of ids * @return set of topics */ public static Set<Topic> getTopic(List<String> topicIds) { Set<Topic> topics = Collections.emptySet(); if (topicIds != null && !topicIds.isEmpty()) { topics = new HashSet<>(); for (String id : topicIds) { Long lid = getLongId(id); if (lid != null) { topics.add(new Topic(lid)); } } } return topics; } /** * Get generic model ids. * * @param idSet the ids set * @param model the GenericModel instance * @param <V> the Set generic * @return set of generic model ids */ public static <V> Set<V> getGenericModelIds(Set<String> idSet, GenericModel model) { Set<V> dataSet = new HashSet<>(); for (String id : idSet) { dataSet.add((V) model.newInstance(id)); } return dataSet; } /** * Get model ids. * * @param set the objects with id * @return the List of ids */ public static Set<String> getGenericModelIds(Set<? extends GenericModel<?>> set) { Set<String> ids; if (set == null || set.isEmpty()) { ids = Collections.emptySet(); } else { ids = new HashSet<>(set.size()); for (GenericModel<?> model : set) { ids.add(model.getStringId()); } } return ids; } /** * Get data transfer object ids. * * @param set the objects with id * @return the List of ids */ public static List<String> getDtoIds(Set<HasId> set) { List<String> ids; if (set == null || set.isEmpty()) { ids = Collections.emptyList(); } else { ids = new ArrayList<>(set.size()); for (HasId hasId : set) { ids.add(hasId.getId()); } } return ids; } /** * Get set of model versions. * * @param set the set * @return versions set */ public static Set<Integer> getGenericModelVersions(Set<? extends HasVersion> set) { Set<Integer> ids; if (set == null || set.isEmpty()) { ids = Collections.emptySet(); } else { ids = new HashSet<>(set.size()); for (HasVersion hasVersion : set) { ids.add(hasVersion.getVersion()); } } return ids; } /** * Get topic ids. * * @param topics the topic set * @return ids <code>List</code> */ public static List<String> getTopicIds(Set<Topic> topics) { List<String> ids = Collections.emptyList(); if (topics != null && !topics.isEmpty()) { ids = new ArrayList<>(); for (Topic topic : topics) { String id = getStringId(topic.getId()); if (id != null) { ids.add(id); } } } return ids; } /** * Get all topic data transfer objects. * * @param topicIds the ids of topics * @return <code>List</code> of topics */ public static List<TopicDto> getTopicDtos(List<String> topicIds) { List<TopicDto> topics = Collections.emptyList(); if (topicIds != null && !topicIds.isEmpty()) { topics = new ArrayList<>(topicIds.size()); for (String id : topicIds) { if (id != null) { TopicDto topicDto = new TopicDto(); topicDto.setId(id); topics.add(topicDto); } } } return topics; } /** * Convert byte array to string. * * @param data array for converting * @return string */ public static String binaryToString(byte[] data) { String body = null; if (data != null) { try { body = new String(data, UTF8); } catch (UnsupportedEncodingException ex) { LOG.warn("Can't convert binary data to string. ", ex); } } return body; } /** * Convert string to byte array. * * @param body string for converting * @return byte array */ public static byte[] stringToBinary(String body) { byte[] data = null; if (body != null) { try { data = body.getBytes(UTF8); } catch (UnsupportedEncodingException ex) { LOG.warn("Can't convert string data to binary. ", ex); } } return data; } /** * This method take string id from <code>GenericModel</code> object. * * @param model <code>GenericModel</code> object * @return the id as string type */ public static String idToString(GenericModel<?> model) { String id = null; if (model != null) { Long lid = model.getId(); id = lid != null ? lid.toString() : null; } return id; } /** * This method convert Long id to String object. * * @param lid basic mongoDB id object type. * @return converted to string id. */ public static String idToString(Long lid) { String id = null; if (lid != null) { id = lid.toString(); } return id; } /** * This method convert list of model objects to dto objects. * * @param <T> Type of model object * @param toDtoList List of model objects. * @return List of converted objects. */ public static <T> List<T> convertDtoList(Collection<? extends ToDto<T>> toDtoList) { List<T> list = Collections.emptyList(); if (toDtoList != null && !toDtoList.isEmpty()) { list = new ArrayList<>(); for (ToDto<T> object : toDtoList) { list.add(object.toDto()); } } return list; } /** * This method convert list of model objects to dto objects. * * @param <T> Type of model object * @param toDtoSet List of model objects. * @return List of converted objects. */ public static <T> Set<T> convertDtoSet(Collection<? extends ToDto<T>> toDtoSet) { Set<T> set = Collections.emptySet(); if (toDtoSet != null && !toDtoSet.isEmpty()) { set = new HashSet<>(); for (ToDto<T> object : toDtoSet) { set.add(object.toDto()); } } return set; } /** * This method convert model object to dto object. * * @param <T> Type of model object * @param dto Model object * @return converted object */ public static <T> T getDto(ToDto<T> dto) { T object = null; if (dto != null) { object = dto.toDto(); } return object; } /** * This method use for coping array bytes. * * @param array bytes * @return copied array of bytes */ public static byte[] getArrayCopy(byte[] array) { byte[] bytes = null; if (array != null) { bytes = Arrays.copyOf(array, array.length); } return bytes; } /** * This method find file by name in context and convert input of file to string. * * @param name of the file * @param clazz the clazz * @return String */ public static String getStringFromFile(String name, Class<?> clazz) { String data = ""; if (isNotBlank(name)) { InputStream is = clazz.getClass().getResourceAsStream(name); if (is != null) { LOG.trace("Load input stream of file {}", is); try { byte[] arrayData = IOUtils.toByteArray(is); if (arrayData != null) { data = new String(arrayData, Charset.forName("UTF-8")); } } catch (IOException ex) { LOG.error("Can't read data from file", ex); } } } return data; } }