/*
* Copyright © 2014 Cask Data, Inc.
*
* 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 co.cask.cdap.internal.specification;
import co.cask.cdap.api.annotation.UseDataSet;
import co.cask.cdap.api.dataset.Dataset;
import co.cask.cdap.internal.lang.FieldVisitor;
import com.google.common.reflect.TypeToken;
import java.lang.reflect.Field;
import java.util.Set;
/**
* A {@link FieldVisitor} that extracts names of all {@link UseDataSet} fields.
*/
public final class DataSetFieldExtractor extends FieldVisitor {
private final Set<String> dataSets;
/**
* Constructs a {@link DataSetFieldExtractor} that store DataSet names extracted from fields.
* @param dataSets set to store datasets
*/
public DataSetFieldExtractor(Set<String> dataSets) {
this.dataSets = dataSets;
}
@Override
public void visit(Object instance, TypeToken<?> inspectType, TypeToken<?> declareType, Field field) {
if (Dataset.class.isAssignableFrom(field.getType())) {
UseDataSet dataset = field.getAnnotation(UseDataSet.class);
if (dataset == null || dataset.value().isEmpty()) {
return;
}
dataSets.add(dataset.value());
}
}
}