/*
* 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.stream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import org.apache.solr.client.solrj.io.Tuple;
import org.apache.solr.client.solrj.io.eval.SimpleEvaluator;
import org.apache.solr.client.solrj.io.stream.expr.Explanation;
import org.apache.solr.client.solrj.io.stream.expr.Explanation.ExpressionType;
import org.apache.solr.client.solrj.io.stream.expr.Expressible;
import org.apache.solr.client.solrj.io.stream.expr.StreamExpression;
import org.apache.solr.client.solrj.io.stream.expr.StreamExpressionParameter;
import org.apache.solr.client.solrj.io.stream.expr.StreamFactory;
public class ColumnEvaluator extends SimpleEvaluator implements Expressible {
private static final long serialVersionUID = 1;
private String name;
private String fieldName;
;
public ColumnEvaluator(StreamExpression expression, StreamFactory factory) throws IOException {
String name = factory.getValueOperand(expression, 0);
String fieldName = factory.getValueOperand(expression, 1);
init(name, fieldName);
}
private void init(String name, String fieldName) {
this.name = name;
this.fieldName = fieldName;
}
public List<Number> evaluate(Tuple tuple) throws IOException {
List<Tuple> tuples = (List<Tuple>)tuple.get(name);
List<Number> column = new ArrayList(tuples.size());
for(Tuple t : tuples) {
Object o = t.get(fieldName);
if(o instanceof Number) {
column.add((Number)o);
} else {
throw new IOException("Found non-numeric in column:"+o.toString());
}
}
return column;
}
@Override
public StreamExpressionParameter toExpression(StreamFactory factory) throws IOException {
StreamExpression expression = new StreamExpression(factory.getFunctionName(getClass()));
return expression;
}
@Override
public Explanation toExplanation(StreamFactory factory) throws IOException {
return new Explanation(nodeId.toString())
.withExpressionType(ExpressionType.EVALUATOR)
.withFunctionName(factory.getFunctionName(getClass()))
.withImplementingClass(getClass().getName())
.withExpression(toExpression(factory).toString());
}
}