/*
* 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.solr.client.solrj.io.eval;
import java.io.IOException;
import java.util.Locale;
import org.apache.solr.client.solrj.io.Tuple;
import org.apache.solr.client.solrj.io.stream.expr.StreamExpression;
import org.apache.solr.client.solrj.io.stream.expr.StreamFactory;
public class CoalesceEvaluator extends ComplexEvaluator {
protected static final long serialVersionUID = 1L;
public CoalesceEvaluator(StreamExpression expression, StreamFactory factory) throws IOException{
super(expression, factory);
if(subEvaluators.size() < 1){
throw new IOException(String.format(Locale.ROOT,"Invalid expression %s - expecting at least one value but found %d",expression,subEvaluators.size()));
}
}
@Override
public Object evaluate(Tuple tuple) throws IOException {
for(StreamEvaluator evaluator : subEvaluators){
Object result = evaluator.evaluate(tuple);
if(null != result){
return result;
}
}
return null;
}
}