Java tutorial
/** * Copyright 2012 Impetus Infotech. * * 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 com.impetus.kundera.graph; import java.lang.reflect.Field; import javax.persistence.GeneratedValue; import org.apache.commons.lang.StringUtils; import com.impetus.kundera.Constants; import com.impetus.kundera.utils.NumericUtils; /** * Provides utility methods for object graph * * @author amresh.singh */ public class ObjectGraphUtils { /** * * @param pk * @param objectClass * @return */ public static String getNodeId(Object pk, Class<?> objectClass) { StringBuffer strBuffer = new StringBuffer(objectClass.getName()); strBuffer.append(Constants.NODE_ID_SEPARATOR); strBuffer.append(pk); return strBuffer.toString(); } /** * * @param nodeId * @return */ public static Object getEntityId(String nodeId) { return nodeId.substring(nodeId.indexOf(Constants.NODE_ID_SEPARATOR) + 1, nodeId.length()); } /** * Validates and set id, in case not set and intended for auto generation. * * @param idField * id field * @param idValue * value of id attribute. * @return returns true if id is not set and @GeneratedValue annotation is * present. Else false. */ public static boolean onAutoGenerateId(Field idField, Object idValue) { if (idField.isAnnotationPresent(GeneratedValue.class)) { return !isIdSet(idValue, idField); } return false; } /** * * @param id * @param idField * @return */ private static boolean isIdSet(Object id, Field idField) { // return true, if it is non blank and not zero in case of numeric // value. if (id != null) { return !(NumericUtils.checkIfZero(id.toString(), idField.getType()) || (StringUtils.isNumeric(id.toString()) && StringUtils.isBlank(id.toString()))); } return false; } }