| // Licensed to the Apache Software Foundation (ASF) under one |
| // or more contributor license agreements. See the NOTICE file |
| // distributed with this work for additional information |
| // regarding copyright ownership. The ASF licenses this file |
| // to you 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.apache.cloudstack.utils.reflectiontostringbuilderutils; |
| |
| import java.lang.reflect.Field; |
| import java.util.Arrays; |
| import java.util.Collection; |
| import java.util.List; |
| import java.util.Optional; |
| import java.util.Set; |
| import java.util.stream.Collectors; |
| import org.apache.commons.lang3.ArrayUtils; |
| import org.apache.commons.lang3.builder.ReflectionToStringBuilder; |
| import org.apache.commons.lang3.builder.ToStringStyle; |
| import org.apache.log4j.Logger; |
| import org.reflections.ReflectionUtils; |
| |
| /** |
| * Provides methods that ReflectionToStringBuilder does not have yet, as: |
| * <br><br> |
| * - Reflect a collection of objects, according to object data structure; ReflectionToStringBuilder will execute a toString based on the collection itself, |
| * and not on the objects contained in it.<br> |
| * - Reflect only selected fields (ReflectionToStringBuilder just has methods to exclude fields). |
| */ |
| public class ReflectionToStringBuilderUtils { |
| protected static final Logger LOGGER = Logger.getLogger(ReflectionToStringBuilderUtils.class); |
| private static final ToStringStyle DEFAULT_STYLE = ToStringStyle.JSON_STYLE; |
| |
| /** |
| * Default separator to join objects when the parameter <b>object</b> is a Collection. |
| */ |
| private static final String DEFAULT_MULTIPLE_VALUES_SEPARATOR = ","; |
| |
| /** |
| * Reflect only selected fields of the object into a JSON formatted String. |
| * @param object Object to be reflected. |
| * @param selectedFields Fields names that must return in JSON. |
| * @return If <b>object</b> is null, returns null.<br> |
| * If <b>selectedFields</b> is null, returns an empty String.<br> |
| * If <b>object</b> is a Collection, returns a JSON array containing the elements, else, returns the object as JSON.<br> |
| */ |
| public static String reflectOnlySelectedFields(Object object, String... selectedFields) { |
| String reflection = reflectOnlySelectedFields(object, DEFAULT_STYLE, ",", selectedFields); |
| |
| if (reflection == null) { |
| return null; |
| } |
| |
| if (isCollection(object)) { |
| return String.format("[%s]", reflection); |
| } |
| |
| return reflection; |
| } |
| |
| /** |
| * Reflect only selected fields of the object into a formatted String. |
| * @param object Object to be reflected. |
| * @param style Style to format the string. |
| * @param multipleValuesSeparator Separator, in case the object is a Collection. |
| * @param selectedFields Fields names that must be reflected. |
| * @return If <b>object</b> is null, returns null.<br> |
| * If <b>selectedFields</b> is null, returns an empty String.<br> |
| * If <b>object</b> is a Collection, returns a <b>style</b> formatted string containing the elements, else, returns the object as the <b>style</b> parameter.<br> |
| */ |
| public static String reflectOnlySelectedFields(Object object, ToStringStyle style, String multipleValuesSeparator, String... selectedFields) { |
| String[] nonSelectedFields = getNonSelectedFields(object, selectedFields); |
| if (nonSelectedFields == null) { |
| return null; |
| } |
| |
| if (ArrayUtils.isEmpty(nonSelectedFields)) { |
| return ""; |
| } |
| |
| String collectionReflection = reflectCollection(object, style, multipleValuesSeparator, nonSelectedFields); |
| return collectionReflection != null ? collectionReflection : getReflectedObject(object, style, nonSelectedFields); |
| } |
| |
| /** |
| * Validate if object is not null. |
| * @param object |
| * @return <b>true</b> if it is not null (valid) or <b>false</b> if it is null (invalid). |
| */ |
| protected static boolean isValidObject(Object object) { |
| if (object != null) { |
| return true; |
| } |
| |
| LOGGER.debug("Object is null, not reflecting it."); |
| return false; |
| } |
| |
| /** |
| * Similar to {@link ReflectionToStringBuilderUtils#reflectOnlySelectedFields(Object, ToStringStyle, String, String...)}, but excluding the fields instead of reflecting which |
| * were selected.<br><br> |
| * This method must be called only to {@link Collection}, as it will reflect the objects contained in it.<br> |
| * To reflect the Collection itself or other objects, see {@link ReflectionToStringBuilder}. |
| * @param object Collection to be reflected. |
| * @param style Style to format the string. |
| * @param multipleValuesSeparator Separator when joining the objects. |
| * @param fieldsToExclude Fields names that must not be reflected. |
| * @return If <b>object</b> is null or is not a Collection, returns null.<br> |
| * If <b>selectedFields</b> is null, returns an empty String.<br> |
| * If <b>object</b> is a Collection, returns a <b>style</b> formatted string containing the not null elements, else, returns the object as the <b>style</b> parameter.<br> |
| */ |
| public static String reflectCollection(Object object, ToStringStyle style, String multipleValuesSeparator, String... fieldsToExclude){ |
| if (!isCollection(object) || !isValidObject(object)) { |
| return null; |
| } |
| |
| return String.valueOf(((Collection) object).stream() |
| .filter(obj -> obj != null) |
| .map(obj -> getReflectedObject(obj, style, fieldsToExclude)) |
| .collect(Collectors.joining(multipleValuesSeparator == null ? DEFAULT_MULTIPLE_VALUES_SEPARATOR : multipleValuesSeparator))); |
| } |
| |
| |
| /** |
| * Similar to {@link ReflectionToStringBuilderUtils#reflectOnlySelectedFields(Object, ToStringStyle, String, String...)}, but reflecting the whole collection.<br><br> |
| * This method must be called only to {@link Collection}, as it will reflect the objects contained in it.<br> |
| * To reflect the Collection itself or other objects, see {@link ReflectionToStringBuilder}. |
| * @param object Collection to be reflected. |
| * @return If <b>object</b> is null or is not a Collection, returns null.<br> |
| * If <b>object</b> is a Collection, returns a <b>style</b> formatted string containing the not null elements, else, returns the object as the <b>style</b> parameter.<br> |
| */ |
| public static String reflectCollection(Object object){ |
| String[] excludeFields = null; |
| return reflectCollection(object, DEFAULT_STYLE, DEFAULT_MULTIPLE_VALUES_SEPARATOR, excludeFields); |
| } |
| |
| /** |
| * Verify if object is a Collection. |
| * @param object |
| * @return <b>true</b> if it is a Collection or <b>false</b> if not. |
| */ |
| protected static boolean isCollection(Object object) { |
| return object instanceof Collection; |
| } |
| |
| /** |
| * Create a new ReflectionToStringBuilder according to parameters. |
| * @param object Object to be reflected. |
| * @param style Style to format the string. |
| * @param fieldsToExclude Fields names to be removed from the reflection. |
| * @return A ReflectionToStringBuilder according to parameters |
| */ |
| protected static String getReflectedObject(Object object, ToStringStyle style, String... fieldsToExclude) { |
| return new ReflectionToStringBuilder(object, style).setExcludeFieldNames(fieldsToExclude).toString(); |
| } |
| |
| /** |
| * Method to retrieve all fields declared in class, except selected fields. If the object is a collection, it will search for any not null object and reflect it. |
| * @param object Object to getReflectionObject. |
| * @param selectedFields Fields names that must no return. |
| * @return Retrieve all fields declared in class, except selected fields. If the object is a collection, it will search for any not null object and reflect it. |
| * @throws SecurityException |
| */ |
| protected static String[] getNonSelectedFields(Object object, String... selectedFields) throws SecurityException { |
| if (ArrayUtils.isEmpty(selectedFields)) { |
| return new String[0]; |
| } |
| |
| Class<?> classToReflect = getObjectClass(object); |
| if (classToReflect == null) { |
| return null; |
| } |
| |
| Set<Field> objectFields = ReflectionUtils.getAllFields(classToReflect); |
| List<String> objectFieldsNames = objectFields.stream().map(objectField -> objectField.getName()).collect(Collectors.toList()); |
| |
| objectFieldsNames.removeAll(Arrays.asList(selectedFields)); |
| return objectFieldsNames.toArray(new String[objectFieldsNames.size()]); |
| } |
| |
| /** |
| * Get class from object. |
| * @param object |
| * @return If <b>object</b> is not a Collection, returns its class.<br> |
| * if it is a Collection, <b>null</b> if it is an empty Collection or has only null values, else, it will return the class of the Collection data object. |
| */ |
| protected static Class<?> getObjectClass(Object object){ |
| if (!isValidObject(object)){ |
| return null; |
| } |
| |
| if (!isCollection(object)) { |
| return object.getClass(); |
| } |
| |
| Collection objectAsCollection = (Collection)object; |
| |
| Optional<Object> anyNotNullObject = objectAsCollection.stream().filter(obj -> obj != null).findAny(); |
| if (anyNotNullObject.isEmpty()) { |
| LOGGER.info(String.format("Collection [%s] is empty or has only null values, not reflecting it.", objectAsCollection)); |
| return null; |
| } |
| |
| return anyNotNullObject.get().getClass(); |
| } |
| } |