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Diffstat (limited to 'feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/extractor/ClassExtractors.java')
| -rw-r--r-- | feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/extractor/ClassExtractors.java | 458 |
1 files changed, 0 insertions, 458 deletions
diff --git a/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/extractor/ClassExtractors.java b/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/extractor/ClassExtractors.java deleted file mode 100644 index bd75995f..00000000 --- a/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/extractor/ClassExtractors.java +++ /dev/null @@ -1,458 +0,0 @@ -/* - * ============LICENSE_START======================================================= - * ONAP - * ================================================================================ - * Copyright (C) 2018-2019 AT&T Intellectual Property. All rights reserved. - * Modifications Copyright (C) 2019-2020 Nordix Foundation - * ================================================================================ - * 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. - * ============LICENSE_END========================================================= - */ - -package org.onap.policy.drools.pooling.extractor; - -import java.lang.reflect.Field; -import java.lang.reflect.Method; -import java.util.Map; -import java.util.Properties; -import java.util.concurrent.ConcurrentHashMap; -import org.apache.commons.lang3.StringUtils; -import org.apache.commons.lang3.tuple.Pair; -import org.slf4j.Logger; -import org.slf4j.LoggerFactory; - -/** - * Extractors for each object class. Properties define how the data is to be - * extracted for a given class, where the properties are similar to the - * following: - * - * <pre> - * <code><a.prefix>.<class.name> = ${event.reqid}</code> - * </pre> - * - * <p>For any given field name (e.g., "reqid"), it first looks for a public "getXxx()" - * method to extract the specified field. If that fails, then it looks for a public field - * by the given name. If that also fails, and the object is a <i>Map</i> subclass, then it - * simply uses the "get(field-name)" method to extract the data from the map. - */ -public class ClassExtractors { - - private static final Logger logger = LoggerFactory.getLogger(ClassExtractors.class); - - /** - * Properties that specify how the data is to be extracted from a given - * class. - */ - private final Properties properties; - - /** - * Property prefix, including a trailing ".". - */ - private final String prefix; - - /** - * Type of item to be extracted. - */ - private final String type; - - /** - * Maps the class name to its extractor. - */ - private final ConcurrentHashMap<String, Extractor> class2extractor = new ConcurrentHashMap<>(); - - /** - * Constructor. - * - * @param props properties that specify how the data is to be extracted from - * a given class - * @param prefix property name prefix, prepended before the class name - * @param type type of item to be extracted - */ - public ClassExtractors(Properties props, String prefix, String type) { - this.properties = props; - this.prefix = (prefix.endsWith(".") ? prefix : prefix + "."); - this.type = type; - } - - /** - * Gets the number of extractors in the map. - * - * @return gets the number of extractors in the map - */ - protected int size() { - return class2extractor.size(); - } - - /** - * Extracts the desired data item from an object. - * - * @param object object from which to extract the data item - * @return the extracted item, or {@code null} if it could not be extracted - */ - public Object extract(Object object) { - if (object == null) { - return null; - } - - Extractor ext = getExtractor(object); - - return ext.extract(object); - } - - /** - * Gets the extractor for the given type of object, creating one if it - * doesn't exist yet. - * - * @param object object whose extracted is desired - * @return an extractor for the object - */ - private Extractor getExtractor(Object object) { - Class<?> clazz = object.getClass(); - Extractor ext = class2extractor.get(clazz.getName()); - - if (ext == null) { - // allocate a new extractor, if another thread doesn't beat us to it - ext = class2extractor.computeIfAbsent(clazz.getName(), xxx -> buildExtractor(clazz)); - } - - return ext; - } - - /** - * Builds an extractor for the class. - * - * @param clazz class for which the extractor should be built - * - * @return a new extractor - */ - private Extractor buildExtractor(Class<?> clazz) { - String value = properties.getProperty(prefix + clazz.getName(), null); - if (value != null) { - // property has config info for this class - build the extractor - return buildExtractor(clazz, value); - } - - /* - * Get the extractor, if any, for the super class or interfaces, but - * don't add one if it doesn't exist - */ - Extractor ext = getClassExtractor(clazz, false); - if (ext != null) { - return ext; - } - - /* - * No extractor defined for for this class or its super class - we - * cannot extract data items from objects of this type, so just - * allocated a null extractor. - */ - logger.warn("missing property {}{}", prefix, clazz.getName()); - return new NullExtractor(); - } - - /** - * Builds an extractor for the class, based on the config value extracted - * from the corresponding property. - * - * @param clazz class for which the extractor should be built - * @param value config value (e.g., "${event.request.id}" - * @return a new extractor - */ - private Extractor buildExtractor(Class<?> clazz, String value) { - if (!value.startsWith("${")) { - logger.warn("property value for {}{} does not start with {}", prefix, clazz.getName(), "'${'"); - return new NullExtractor(); - } - - if (!value.endsWith("}")) { - logger.warn("property value for {}{} does not end with '}'", prefix, clazz.getName()); - return new NullExtractor(); - } - - // get the part in the middle - String val = value.substring(2, value.length() - 1); - if (val.startsWith(".")) { - logger.warn("property value for {}{} begins with '.'", prefix, clazz.getName()); - return new NullExtractor(); - } - - if (val.endsWith(".")) { - logger.warn("property value for {}{} ends with '.'", prefix, clazz.getName()); - return new NullExtractor(); - } - - // everything's valid - create the extractor - try { - ComponetizedExtractor ext = new ComponetizedExtractor(clazz, val.split("[.]")); - - /* - * If there's only one extractor, then just return it, otherwise - * return the whole extractor. - */ - return (ext.extractors.length == 1 ? ext.extractors[0] : ext); - - } catch (ExtractorException e) { - logger.warn("cannot build extractor for {}", clazz.getName(), e); - return new NullExtractor(); - } - } - - /** - * Gets the extractor for a class, examining all super classes and - * interfaces. - * - * @param clazz class whose extractor is desired - * @param addOk {@code true} if the extractor may be added, provided the - * property is defined, {@code false} otherwise - * @return the extractor to be used for the class, or {@code null} if no - * extractor has been defined yet - */ - private Extractor getClassExtractor(Class<?> clazz, boolean addOk) { - if (clazz == null) { - return null; - } - - Extractor ext = null; - - if (addOk) { - String val = properties.getProperty(prefix + clazz.getName(), null); - - if (val != null) { - /* - * A property is defined for this class, so create the extractor - * for it. - */ - return class2extractor.computeIfAbsent(clazz.getName(), xxx -> buildExtractor(clazz)); - } - } - - // see if the superclass has an extractor - if ((ext = getClassExtractor(clazz.getSuperclass(), true)) != null) { - return ext; - } - - // check the interfaces, too - for (Class<?> clz : clazz.getInterfaces()) { - if ((ext = getClassExtractor(clz, true)) != null) { - break; - } - } - - return ext; - } - - /** - * Extractor that always returns {@code null}. Used when no extractor could - * be built for a given object type. - */ - private class NullExtractor implements Extractor { - - @Override - public Object extract(Object object) { - logger.info("cannot extract {} from {}", type, object.getClass()); - return null; - } - } - - /** - * Component-ized extractor. Extracts an object that is referenced - * hierarchically, where each name identifies a particular component within - * the hierarchy. Supports retrieval from {@link Map} objects, as well as - * via getXxx() methods, or by direct field retrieval. - * - * <p>Note: this will <i>not</i> work if POJOs are contained within a Map. - */ - private class ComponetizedExtractor implements Extractor { - - /** - * Extractor for each component. - */ - private final Extractor[] extractors; - - /** - * Constructor. - * - * @param clazz the class associated with the object at the root of the - * hierarchy - * @param names name associated with each component - * @throws ExtractorException extractor exception - */ - public ComponetizedExtractor(Class<?> clazz, String[] names) throws ExtractorException { - this.extractors = new Extractor[names.length]; - - Class<?> clz = clazz; - - for (int x = 0; x < names.length; ++x) { - String comp = names[x]; - - Pair<Extractor, Class<?>> pair = buildExtractor(clz, comp); - - extractors[x] = pair.getLeft(); - clz = pair.getRight(); - } - } - - /** - * Builds an extractor for the given component of an object. - * - * @param clazz type of object from which the component will be - * extracted - * @param comp name of the component to extract - * @return a pair containing the extractor and the extracted object's - * type - * @throws ExtractorException extrator exception - */ - private Pair<Extractor, Class<?>> buildExtractor(Class<?> clazz, String comp) throws ExtractorException { - - Pair<Extractor, Class<?>> pair = getMethodExtractor(clazz, comp); - - if (pair == null) { - pair = getFieldExtractor(clazz, comp); - } - - if (pair == null) { - pair = getMapExtractor(clazz, comp); - } - - - // didn't find an extractor - if (pair == null) { - throw new ExtractorException("class " + clazz + " contains no element " + comp); - } - - return pair; - } - - @Override - public Object extract(Object object) { - Object obj = object; - - for (Extractor ext : extractors) { - if (obj == null) { - break; - } - - obj = ext.extract(obj); - } - - return obj; - } - - /** - * Gets an extractor that invokes a getXxx() method to retrieve the - * object. - * - * @param clazz container's class - * @param name name of the property to be retrieved - * @return a new extractor, or {@code null} if the class does not - * contain the corresponding getXxx() method - * @throws ExtractorException if the getXxx() method is inaccessible - */ - private Pair<Extractor, Class<?>> getMethodExtractor(Class<?> clazz, String name) throws ExtractorException { - Method meth; - - String nm = "get" + StringUtils.capitalize(name); - - try { - meth = clazz.getMethod(nm); - - Class<?> retType = meth.getReturnType(); - if (retType == void.class) { - // it's a void method, thus it won't return an object - return null; - } - - return Pair.of(new MethodExtractor(meth), retType); - - } catch (NoSuchMethodException expected) { - // no getXxx() method, maybe there's a field by this name - logger.debug("no method {} in {}", nm, clazz.getName(), expected); - return null; - - } catch (SecurityException e) { - throw new ExtractorException("inaccessible method " + clazz + "." + nm, e); - } - } - - /** - * Gets an extractor for a field within the object. - * - * @param clazz container's class - * @param name name of the field whose value is to be extracted - * @return a new extractor, or {@code null} if the class does not - * contain the given field - * @throws ExtractorException if the field is inaccessible - */ - private Pair<Extractor, Class<?>> getFieldExtractor(Class<?> clazz, String name) throws ExtractorException { - - Field field = getClassField(clazz, name); - if (field == null) { - return null; - } - - return Pair.of(new FieldExtractor(field), field.getType()); - } - - /** - * Gets an extractor for an item within a Map object. - * - * @param clazz container's class - * @param key item key within the map - * @return a new extractor, or {@code null} if the class is not a Map - * subclass - */ - private Pair<Extractor, Class<?>> getMapExtractor(Class<?> clazz, String key) { - - if (!Map.class.isAssignableFrom(clazz)) { - return null; - } - - /* - * Don't know the value's actual type, so we'll assume it's a Map - * for now. Things should still work OK, as this is only used to - * direct the constructor on what type of extractor to create next. - * If the object turns out not to be a map, then the MapExtractor - * for the next component will just return null. - */ - return Pair.of(new MapExtractor(key), Map.class); - } - - /** - * Gets field within a class, examining all super classes and - * interfaces. - * - * @param clazz class whose field is desired - * @param name name of the desired field - * @return the field within the class, or {@code null} if the field does - * not exist - * @throws ExtractorException if the field is inaccessible - */ - private Field getClassField(Class<?> clazz, String name) throws ExtractorException { - if (clazz == null) { - return null; - } - - try { - return clazz.getField(name); - - } catch (NoSuchFieldException expected) { - // no field by this name - try super class & interfaces - logger.debug("no field {} in {}", name, clazz.getName(), expected); - return null; - - } catch (SecurityException e) { - throw new ExtractorException("inaccessible field " + clazz + "." + name, e); - } - } - } -} |