Github user steveblackmon commented on a diff in the pull request:
https://github.com/apache/incubator-streams/pull/150#discussion_r21704144
--- Diff:
streams-components/streams-converters/src/main/java/org/apache/streams/converter/ActivityConverterProcessor.java
---
@@ -0,0 +1,260 @@
+/*
+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.streams.converter;
+
+import com.google.common.base.Preconditions;
+import com.google.common.collect.Lists;
+import com.google.common.collect.Maps;
+import com.google.common.collect.Sets;
+import org.apache.streams.core.StreamsDatum;
+import org.apache.streams.core.StreamsProcessor;
+import org.apache.streams.core.util.DatumUtils;
+import org.apache.streams.data.ActivityConverter;
+import org.apache.streams.data.DocumentClassifier;
+import org.apache.streams.data.util.ActivityUtil;
+import org.apache.streams.exceptions.ActivityConversionException;
+import org.apache.streams.pojo.json.Activity;
+import org.reflections.Reflections;
+import org.reflections.util.ClasspathHelper;
+import org.reflections.util.ConfigurationBuilder;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+
+/**
+ * ActivityConverterProcessor is a utility processor for converting any
datum document
+ * to an Activity.
+ *
+ * By default it will handle string json and objectnode representation of
existing Activities.
+ *
+ * Implementations can add DocumentClassifiers and
ActivityConverterResolvers to the processor
+ * to ensure additional ActivityConverters will be resolved and applied.
+ *
+ * A DocumentClassifier's reponsibility is to recognize document formats
and label them, using
+ * a jackson-compatible POJO class.
+ *
+ * An ActivityConverterResolver's reponsibility is to identify
ActivityConverter implementations
+ * capable of converting a raw document associated with that POJO class
into an activity.
+ *
+ */
+public class ActivityConverterProcessor implements StreamsProcessor {
+
+ private final static Logger LOGGER =
LoggerFactory.getLogger(ActivityConverterProcessor.class);
+
+ private List<DocumentClassifier> classifiers;
+ private List<ActivityConverter> converters;
+
+ private ActivityConverterProcessorConfiguration configuration;
+
+ public ActivityConverterProcessor() {
+ this.classifiers = Lists.newArrayList();
+ this.converters = Lists.newArrayList();
+ }
+
+ public
ActivityConverterProcessor(ActivityConverterProcessorConfiguration
configuration) {
+ this.classifiers = Lists.newArrayList();
+ this.converters = Lists.newArrayList();
+ this.configuration = configuration;
+ }
+
+ @Override
+ public List<StreamsDatum> process(StreamsDatum entry) {
+
+ List<StreamsDatum> result = Lists.newLinkedList();
+ Object document = entry.getDocument();
+
+ try {
+
+ // first determine which classes this document might actually
be
+ List<Class> detectedClasses = detectClasses(document);
+
+ if( detectedClasses.size() == 0 ) {
+ LOGGER.warn("Unable to classify");
+ return null;
+ } else {
+ LOGGER.debug("Classified document as " + detectedClasses);
+ }
+
+ // for each of these classes:
+ // use TypeUtil to switch the document to that type
+ Map<Class, Object> typedDocs =
convertToDetectedClasses(detectedClasses, document);
+
+ if( typedDocs.size() == 0 ) {
+ LOGGER.warn("Unable to convert to any detected Class");
+ return result;
+ }
+ else {
+ LOGGER.debug("Document has " + typedDocs.size() + "
representations: " + typedDocs.toString());
+ }
+
+ // for each specified / discovered converter
+ for( ActivityConverter converter : converters ) {
+
+ Object typedDoc = typedDocs.get(converter.requiredClass());
+
+ // if the document can be typed as the required class
+ if( typedDoc != null ) {
+
+ StreamsDatum datum = DatumUtils.cloneDatum(entry);
+
+ // let the converter create activities if it can
+ List<Activity> activities;
+ try {
+ activities = convertToActivity(converter,
typedDoc);
+
+ if( activities != null && activities.size() > 0) {
+
+ for (Activity activity : activities) {
+
+ if (activity != null) {
+
+ // only accept valid activities
+ // this primitive validity check
should be replaced with
+ // one that applies javax.validation
to JSR303 annotations
+ // on the Activity json schema once
a suitable implementation
+ // is found.
+ if (ActivityUtil.isValid(activity)) {
+ datum.setDocument(activity);
+ datum.setId(activity.getId());
+ result.add(datum);
+ } else {
+
LOGGER.debug(converter.getClass().getCanonicalName() + " produced invalid
Activity converting " +
converter.requiredClass().getClass().getCanonicalName());
+ }
+
+ } else {
+
LOGGER.debug(converter.getClass().getCanonicalName() + " returned null
converting " + converter.requiredClass().getClass().getCanonicalName() + " to
Activity");
+ }
+
+ }
+ }
+ } catch( Exception e ) {
+ LOGGER.debug("convertToActivity caught exception "
+ e.getMessage());
+ }
+
+
+
+ }
+
+ }
+
+ } catch( Exception e ) {
+ LOGGER.warn("General exception in process! " + e.getMessage());
+ } finally {
+ return result;
+ }
+
+ }
+
+ protected List<Activity> convertToActivity(ActivityConverter
converter, Object document) {
+
+ List<Activity> activities = Lists.newArrayList();
+ try {
+ activities = converter.toActivityList(document);
+ } catch (ActivityConversionException e1) {
+ LOGGER.debug(converter.getClass().getCanonicalName() + "
unable to convert " + converter.requiredClass().getClass().getCanonicalName() +
" to Activity");
+ }
+ return activities;
+
+ }
+
+ protected List<Class> detectClasses(Object document) {
+
+ Set<Class> detectedClasses = Sets.newConcurrentHashSet();
+ for( DocumentClassifier classifier : classifiers ) {
+ List<Class> detected = classifier.detectClasses(document);
+ if( detected != null && detected.size() > 0)
+ detectedClasses.addAll(detected);
+ }
+
+ return Lists.newArrayList(detectedClasses);
+ }
+
+ private Map<Class, Object> convertToDetectedClasses(List<Class>
datumClasses, Object document) {
+
+ Map<Class, Object> convertedDocuments = Maps.newHashMap();
+ for( Class detectedClass : datumClasses ) {
+
+ Object typedDoc;
+ if (detectedClass.isInstance(document))
+ typedDoc = document;
+ else
+ typedDoc = TypeConverterUtil.convert(document,
detectedClass);
+
+ if( typedDoc != null )
+ convertedDocuments.put(detectedClass, typedDoc);
+ }
+
+ return convertedDocuments;
+ }
+
+ @Override
+ public void prepare(Object configurationObject) {
+// Preconditions.checkArgument(configurationObject instanceof
ActivityConverterProcessorConfiguration);
--- End diff --
removed
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