Java tutorial
/** * The MIT License * * Copyright (C) 2007 Asterios Raptis * * Permission is hereby granted, free of charge, to any person obtaining * a copy of this software and associated documentation files (the * "Software"), to deal in the Software without restriction, including * without limitation the rights to use, copy, modify, merge, publish, * distribute, sublicense, and/or sell copies of the Software, and to * permit persons to whom the Software is furnished to do so, subject to * the following conditions: * * The above copyright notice and this permission notice shall be * included in all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */ package de.alpharogroup.lang; import java.io.IOException; import java.io.Serializable; import java.lang.reflect.Array; import java.lang.reflect.InvocationTargetException; import java.lang.reflect.Method; import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Map; import org.apache.commons.beanutils.BeanComparator; import org.apache.commons.beanutils.BeanUtils; import org.apache.log4j.Logger; import de.alpharogroup.io.ChangedAttributeResult; import de.alpharogroup.io.SerializedObjectUtils; import de.alpharogroup.reflection.ReflectionUtils; /** * The Class ObjectExtensions provides methods to clone, copy and compare objects. It also provides * methods to find changed data between Objects. */ public final class ObjectExtensions { /** The Constant logger. */ private static final Logger logger = Logger.getLogger(ObjectExtensions.class.getName()); /** * Try to clone the given generic object. * * @param <T> * the generic type * @param object * the object to clone * @return The cloned object or null if the clone process failed. */ @SuppressWarnings("unchecked") public static <T> T clone(final T object) { return (T) cloneObjectQuietly(object); } /** * Try to clone the given object. * * @param object * The object to clone. * @return The cloned object or null if the clone process failed. * @throws NoSuchMethodException * the no such method exception * @throws SecurityException * Thrown if the security manager indicates a security violation. * @throws IllegalAccessException * the illegal access exception * @throws IllegalArgumentException * the illegal argument exception * @throws InvocationTargetException * the invocation target exception * @throws ClassNotFoundException * the class not found exception * @throws InstantiationException * the instantiation exception * @throws IOException * Signals that an I/O exception has occurred. */ public static Object cloneObject(final Object object) throws NoSuchMethodException, SecurityException, IllegalAccessException, IllegalArgumentException, InvocationTargetException, ClassNotFoundException, InstantiationException, IOException { Object clone = null; // Try to clone the object if it implements Serializable. if (object instanceof Serializable) { clone = SerializedObjectUtils.copySerializedObject((Serializable) object); if (clone != null) { return clone; } } // Try to clone the object if it is Cloneble. if (clone == null && object instanceof Cloneable) { if (object.getClass().isArray()) { final Class<?> componentType = object.getClass().getComponentType(); if (componentType.isPrimitive()) { int length = Array.getLength(object); clone = Array.newInstance(componentType, length); while (length-- > 0) { Array.set(clone, length, Array.get(object, length)); } } else { clone = ((Object[]) object).clone(); } if (clone != null) { return clone; } } final Class<?> clazz = object.getClass(); final Method cloneMethod = clazz.getMethod("clone", (Class[]) null); clone = cloneMethod.invoke(object, (Object[]) null); if (clone != null) { return clone; } } // Try to clone the object by copying all his properties with // the BeanUtils.copyProperties() method. if (clone == null) { clone = ReflectionUtils.getNewInstance(object); BeanUtils.copyProperties(clone, object); } return clone; } /** * Try to clone the given object quietly. * * @param object * The object to clone. * @return The cloned object or null if the clone process failed. */ public static Object cloneObjectQuietly(final Object object) { Object clone = null; try { clone = cloneObject(object); } catch (final NoSuchMethodException e) { logger.error("Try to clone the object with " + "reflection and call the clone method. " + "Thrown exception: NoSuchMethodException", e); } catch (final SecurityException e) { logger.error("Try to clone the object with " + "reflection and call the clone method. " + "Thrown exception: SecurityException", e); } catch (final IllegalAccessException e) { logger.error("Try to clone the object with " + "org.apache.commons.beanutils.BeanUtils failed " + "cause of IllegalAccessException. Could not found from ReflectionUtils.", e); } catch (final IllegalArgumentException e) { logger.error("Try to clone the object with " + "reflection and call the clone method. " + "Thrown exception: IllegalArgumentException", e); } catch (final InvocationTargetException e) { logger.error("Try to clone the object with " + "org.apache.commons.beanutils.BeanUtils failed " + "cause of InvocationTargetException. Could not found from ReflectionUtils.", e); } catch (final ClassNotFoundException e) { logger.error("Try to clone the object with " + "org.apache.commons.beanutils.BeanUtils failed " + "cause of ClassNotFoundException. Could not found from ReflectionUtils.", e); } catch (final InstantiationException e) { logger.error("Try to clone the object with " + "org.apache.commons.beanutils.BeanUtils failed " + "cause of InstantiationException. Could not found from ReflectionUtils.", e); } catch (final IOException e) { logger.error("Try to clone the object with " + "SerializedObjectUtils.copySerializedObject((Serializable)object) " + "cause of IOException.", e); } return clone; } /** * Compares the given two objects. * * @param sourceOjbect * the source ojbect * @param objectToCompare * the object to compare * @return true, if successful otherwise false * @throws IllegalAccessException * the illegal access exception * @throws InvocationTargetException * the invocation target exception * @throws NoSuchMethodException * the no such method exception */ @SuppressWarnings("rawtypes") public static boolean compare(final Object sourceOjbect, final Object objectToCompare) throws IllegalAccessException, InvocationTargetException, NoSuchMethodException { if (sourceOjbect == null || objectToCompare == null || !sourceOjbect.getClass().equals(objectToCompare.getClass())) { throw new IllegalArgumentException("Object should not be null and be the same type."); } final Map beanDescription = BeanUtils.describe(sourceOjbect); beanDescription.remove("class"); final Map clonedBeanDescription = BeanUtils.describe(objectToCompare); clonedBeanDescription.remove("class"); for (final Object key : beanDescription.keySet()) { if (compareTo(sourceOjbect, objectToCompare, key.toString()) != 0) { return false; } } return true; } /** * Compares the given object over the given property. * * @param sourceOjbect * the source ojbect * @param objectToCompare * the object to compare * @param property * the property * @return the int * @throws IllegalAccessException * the illegal access exception * @throws InvocationTargetException * the invocation target exception * @throws NoSuchMethodException * the no such method exception */ @SuppressWarnings({ "unchecked", "rawtypes" }) public static int compareTo(final Object sourceOjbect, final Object objectToCompare, final String property) throws IllegalAccessException, InvocationTargetException, NoSuchMethodException { final Map<?, ?> beanDescription = BeanUtils.describe(sourceOjbect); beanDescription.remove("class"); final Map<?, ?> clonedBeanDescription = BeanUtils.describe(objectToCompare); clonedBeanDescription.remove("class"); final Object sourceAttribute = beanDescription.get(property); final Object changedAttribute = clonedBeanDescription.get(property); if (sourceAttribute == null && changedAttribute == null) { return 0; } if (sourceAttribute != null && changedAttribute == null) { return 1; } else if (sourceAttribute == null && changedAttribute != null) { return -1; } return new BeanComparator(property).compare(sourceOjbect, objectToCompare); } /** * Compares the given object over the given property quietly. * * @param sourceOjbect * the source ojbect * @param objectToCompare * the object to compare * @param property * the property * @return the int */ @SuppressWarnings({ "unchecked", "rawtypes" }) public static int compareToQuietly(final Object sourceOjbect, final Object objectToCompare, final String property) { Map<?, ?> beanDescription = null; try { beanDescription = BeanUtils.describe(sourceOjbect); } catch (IllegalAccessException | InvocationTargetException | NoSuchMethodException e) { logger.error("BeanUtils.describe(sourceOjbect) throws an exception...", e); return 0; } beanDescription.remove("class"); Map<?, ?> clonedBeanDescription = null; try { clonedBeanDescription = BeanUtils.describe(objectToCompare); } catch (IllegalAccessException | InvocationTargetException | NoSuchMethodException e) { logger.error("BeanUtils.describe(objectToCompare) throws an exception...", e); return 0; } clonedBeanDescription.remove("class"); final Object sourceAttribute = beanDescription.get(property); final Object changedAttribute = clonedBeanDescription.get(property); if (sourceAttribute == null && changedAttribute == null) { return 0; } if (sourceAttribute != null && changedAttribute == null) { return 1; } else if (sourceAttribute == null && changedAttribute != null) { return -1; } return new BeanComparator(property).compare(sourceOjbect, objectToCompare); } /** * Copy the given original object to the given destination object. * * @param <DESTINATION> * the generic type of the destination object. * @param <ORIGINAL> * the generic type of the original object. * @param destination * the destination object. * @param original * the original object. * @throws IllegalAccessException * the illegal access exception * @throws InvocationTargetException * the invocation target exception */ public static final <DESTINATION, ORIGINAL> void copy(final DESTINATION destination, final ORIGINAL original) throws IllegalAccessException, InvocationTargetException { BeanUtils.copyProperties(destination, original); } /** * Copy quietly the given original object to the given destination object. * * @param <DESTINATION> * the generic type of the destination object. * @param <ORIGINAL> * the generic type of the original object. * @param destination * the destination object. * @param original * the original object. * @return the destination object. */ public static final <DESTINATION, ORIGINAL> DESTINATION copyQuietly(final DESTINATION destination, final ORIGINAL original) { try { copy(destination, original); } catch (final IllegalAccessException e) { return null; } catch (final InvocationTargetException e) { return null; } return destination; } /** * Gets the changed data. * * @param sourceOjbect * the source ojbect * @param objectToCompare * the object to compare * @return the changed data * @throws IllegalAccessException * the illegal access exception * @throws InvocationTargetException * the invocation target exception * @throws NoSuchMethodException * the no such method exception */ @SuppressWarnings("rawtypes") public static List<ChangedAttributeResult> getChangedData(final Object sourceOjbect, final Object objectToCompare) throws IllegalAccessException, InvocationTargetException, NoSuchMethodException { if (sourceOjbect == null || objectToCompare == null || !sourceOjbect.getClass().equals(objectToCompare.getClass())) { throw new IllegalArgumentException("Object should not be null and be the same type."); } final Map beanDescription = BeanUtils.describe(sourceOjbect); beanDescription.remove("class"); final Map clonedBeanDescription = BeanUtils.describe(objectToCompare); clonedBeanDescription.remove("class"); final List<ChangedAttributeResult> changedData = new ArrayList<ChangedAttributeResult>(); for (final Object key : beanDescription.keySet()) { if (compareTo(sourceOjbect, objectToCompare, key.toString()) != 0) { final Object sourceAttribute = beanDescription.get(key); final Object changedAttribute = clonedBeanDescription.get(key); changedData.add(new ChangedAttributeResult(key, sourceAttribute, changedAttribute)); } } return changedData; } /** * Compares the given two objects and gets the changed data. * * @param sourceOjbect * the source ojbect * @param objectToCompare * the object to compare * @return the changed data * @throws IllegalAccessException * the illegal access exception * @throws InvocationTargetException * the invocation target exception * @throws NoSuchMethodException * the no such method exception */ @SuppressWarnings("rawtypes") public static Map<Object, ChangedAttributeResult> getChangedDataMap(final Object sourceOjbect, final Object objectToCompare) throws IllegalAccessException, InvocationTargetException, NoSuchMethodException { if (sourceOjbect == null || objectToCompare == null || !sourceOjbect.getClass().equals(objectToCompare.getClass())) { throw new IllegalArgumentException("Object should not be null and be the same type."); } final Map beanDescription = BeanUtils.describe(sourceOjbect); beanDescription.remove("class"); final Map clonedBeanDescription = BeanUtils.describe(objectToCompare); clonedBeanDescription.remove("class"); final Map<Object, ChangedAttributeResult> changedData = new HashMap<Object, ChangedAttributeResult>(); for (final Object key : beanDescription.keySet()) { final Object sourceAttribute = beanDescription.get(key); final Object changedAttribute = clonedBeanDescription.get(key); if (compareTo(sourceOjbect, objectToCompare, key.toString()) != 0) { changedData.put(key, new ChangedAttributeResult(key, sourceAttribute, changedAttribute)); } } return changedData; } /** * Gets the compare to result. * * @param sourceOjbect * the source ojbect * @param objectToCompare * the object to compare * @return the compare to result * @throws IllegalAccessException * the illegal access exception * @throws InvocationTargetException * the invocation target exception * @throws NoSuchMethodException * the no such method exception */ @SuppressWarnings("rawtypes") public static Map<String, Integer> getCompareToResult(final Object sourceOjbect, final Object objectToCompare) throws IllegalAccessException, InvocationTargetException, NoSuchMethodException { if (sourceOjbect == null || objectToCompare == null || !sourceOjbect.getClass().equals(objectToCompare.getClass())) { throw new IllegalArgumentException("Object should not be null and be the same type."); } final Map beanDescription = BeanUtils.describe(sourceOjbect); beanDescription.remove("class"); final Map clonedBeanDescription = BeanUtils.describe(objectToCompare); clonedBeanDescription.remove("class"); final Map<String, Integer> compareResult = new HashMap<String, Integer>(); for (final Object key : beanDescription.keySet()) { compareResult.put(key.toString(), Integer.valueOf(compareTo(sourceOjbect, objectToCompare, key.toString()))); } return compareResult; } /** * Checks if is copyable and copies if its possible otherwise it returns false. * * @param <DESTINATION> * the generic type of the destination object. * @param <ORIGINAL> * the generic type of the original object. * @param destination * the destination object. * @param original * the original object. * @return true, if is copyable otherwise false. */ public static final <DESTINATION, ORIGINAL> boolean isCopyable(final DESTINATION destination, final ORIGINAL original) { return copyQuietly(destination, original) != null; } /** * Private constructor. */ private ObjectExtensions() { super(); } }