org.eclipse.osbp.runtime.common/src/org/eclipse/osbp/runtime/common/hash/HashUtil.java

/**
 * Copyright (c) 2011, 2015 - Lunifera GmbH (Gross Enzersdorf, Austria), Loetz GmbH&Co.KG (69115 Heidelberg, Germany)
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0 
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *         Florian Pirchner - Initial implementation
 */
package org.eclipse.osbp.runtime.common.hash;

import org.eclipse.osbp.runtime.common.annotations.FindIdHelper;

import com.google.common.hash.Hashing;

// TODO: Auto-generated Javadoc
/**
 * Common HashUtil.
 */
public class HashUtil {

	/**
	 * Creates a hash code for an object with the class name and objects
	 * hashCode.
	 * <p>
	 * <i>org.eclipse.osbp.dtos.ItemDTO(id=17):</i>
	 * <code>hash("org.eclipse.osbp.dtos.ItemDto({object.hashCode()})")</code>
	 *
	 * @param clazz
	 *            the clazz
	 * @param object
	 *            the object
	 * @return the string
	 */
	public static String createObjectWithIdHash(Class<?> clazz, Object object) {
		return createObjectWithIdHash(clazz.getCanonicalName(), object);
	}

	/**
	 * Creates a hash code for an object with the class name and objects
	 * hashCode.
	 * <p>
	 * <i>org.eclipse.osbp.dtos.ItemDTO(id=17):</i>
	 * <code>hash("org.eclipse.osbp.dtos.ItemDto({object.hashCode()})")</code>
	 *
	 * @param objectName
	 *            the object name
	 * @param object
	 *            the object
	 * @return the string
	 */
	public static String createObjectWithIdHash(String objectName, Object object) {
		Object id = FindIdHelper.getIdValue(object);
		if (id instanceof Number) {
			if (((Number) id).longValue() == 0) {
				id = object.hashCode();
			}
		} else if (id == null) {
			id = object.hashCode();
		}

		return Hashing.sha1().hashBytes(String.format("%s(%s)", objectName, String.valueOf(id)).getBytes()).toString();
	}

}