DefaultAnnotationTransformer.java

/*
 * Copyright (c) 2014-2015 Janith Bandara, This source is a part of
 * Audit4j - An open source auditing framework.
 * http://audit4j.org
 *
 * 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 org.audit4j.core;

import java.lang.annotation.Annotation;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.List;

import org.audit4j.core.annotation.Audit;
import org.audit4j.core.annotation.AuditField;
import org.audit4j.core.annotation.DeIdentify;
import org.audit4j.core.annotation.IgnoreAudit;
import org.audit4j.core.dto.AnnotationAuditEvent;
import org.audit4j.core.dto.AuditEvent;
import org.audit4j.core.dto.Field;

/**
 * The Class DefaultAnnotationTransformer use to transform annotation information in to
 * simple audit event.
 * 
 * @author <a href="mailto:janith3000@gmail.com">Janith Bandara</a>
 * 
 * @since 2.0.0
 */
public class DefaultAnnotationTransformer implements AnnotationTransformer<AuditEvent> {

	private final static String ACTION = "action";

	// Default Fields serializer
	private ObjectSerializer serializer;

	public DefaultAnnotationTransformer() {
		this.serializer = new ObjectToFieldsSerializer();
	}

	public DefaultAnnotationTransformer(ObjectSerializer objectSerializer) {
		this.serializer = objectSerializer;
	}

	/**
	 * Transform annotation informations to Audit Event object.
	 * 
	 * @param annotationEvent
	 *            the annotation event
	 * @return the audit event
	 * @since 2.0.0
	 */
	@Override
	public AuditEvent transformToEvent(AnnotationAuditEvent annotationEvent) {
		AuditEvent event = null;

		if (annotationEvent.getClazz().isAnnotationPresent(Audit.class)
				&& !annotationEvent.getMethod().isAnnotationPresent(IgnoreAudit.class)) {
			event = new AuditEvent();
			Audit audit = annotationEvent.getClazz().getAnnotation(Audit.class);

			// Extract fields
			event.setFields(getFields(annotationEvent.getMethod(), annotationEvent.getArgs()));

			// Extract Actor
			String annotationAction = audit.action();
			if (ACTION.equals(annotationAction)) {
				event.setAction(annotationEvent.getMethod().getName());
			} else {
				event.setAction(annotationAction);
			}

			// Extract repository
			event.setRepository(audit.repository());

			event.setActor(annotationEvent.getActor());
			event.setOrigin(annotationEvent.getOrigin());
		} else if (!annotationEvent.getClazz().isAnnotationPresent(Audit.class)
				&& annotationEvent.getMethod().isAnnotationPresent(Audit.class)) {
			event = new AuditEvent();
			Audit audit = annotationEvent.getMethod().getAnnotation(Audit.class);

			// Extract fields
			event.setFields(getFields(annotationEvent.getMethod(), annotationEvent.getArgs()));

			// Extract Actor
			String annotationAction = audit.action();
			if (ACTION.equals(annotationAction)) {
				event.setAction(annotationEvent.getMethod().getName());
			} else {
				event.setAction(annotationAction);
			}

			// Extract repository
			event.setRepository(audit.repository());

			event.setActor(annotationEvent.getActor());
			event.setOrigin(annotationEvent.getOrigin());
		}

		return event;
	}

	/**
	 * Extract fields based on annotations.
	 * 
	 * @param method
	 *            : Class method with annotations.
	 * @param params
	 *            : Method parameter values.
	 * 
	 * @return list of fields extracted from method.
	 * 
	 * @since 2.4.1
	 */
	private List<Field> getFields(final Method method, final Object[] params) {
		final Annotation[][] parameterAnnotations = method.getParameterAnnotations();

		final List<Field> fields = new ArrayList<Field>();

		int i = 0;
		String paramName = null;
		for (final Annotation[] annotations : parameterAnnotations) {
			final Object object = params[i++];
			boolean ignoreFlag = false;
			DeIdentify deidentify = null;
			for (final Annotation annotation : annotations) {
				if (annotation instanceof IgnoreAudit) {
					ignoreFlag = true;
					break;
				}
				if (annotation instanceof AuditField) {
					final AuditField field = (AuditField) annotation;
					paramName = field.field();
				}
				if (annotation instanceof DeIdentify) {
					deidentify = (DeIdentify) annotation;
				}
			}

			if (ignoreFlag) {

			} else {
				if (null == paramName) {
					paramName = "arg" + i;
				}
				serializer.serialize(fields, object, paramName, deidentify);
			}

			paramName = null;
		}
		return fields;
	}

	public void setSerializer(ObjectSerializer serializer) {
		this.serializer = serializer;
	}
}