package com.thinkbiganalytics.feedmgr;
/*-
* #%L
* thinkbig-feed-manager-core
* %%
* Copyright (C) 2017 ThinkBig Analytics
* %%
* 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.
* #L%
*/
import com.thinkbiganalytics.annotations.AnnotatedFieldProperty;
import com.thinkbiganalytics.feedmgr.rest.model.FeedMetadata;
import java.util.List;
/**
* Utiltiy to inspect a class or {@link FeedMetadata} object and return information about all the fields annotated with {@link com.thinkbiganalytics.metadata.MetadataField}
* Fields annotated with {@link com.thinkbiganalytics.metadata.MetadataField} are accessible when registering a template in Kylo and can be injected into a NiFi flow when the feed is created.
*/
public class MetadataFields {
private List<AnnotatedFieldProperty> properties = null;
private MetadataFieldAnnotationFieldNameResolver resolver;
private MetadataFields() {
resolver = new MetadataFieldAnnotationFieldNameResolver();
}
public static MetadataFields getInstance() {
return LazyHolder.INSTANCE;
}
public List<AnnotatedFieldProperty> getProperties(Class clazz) {
if (properties == null) {
properties = resolver.getProperties(clazz);
}
return properties;
}
public String getMatchingPropertyDescriptor(FeedMetadata feedMetadata, String propertyDescriptor) {
if (properties == null) {
getProperties(FeedMetadata.class);
}
return resolver.getMatchingPropertyDescriptor(propertyDescriptor);
}
private static class LazyHolder {
static final MetadataFields INSTANCE = new MetadataFields();
}
}