/*
* 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.flink.streaming.api.functions.windowing.delta.extractor;
import org.apache.flink.annotation.Internal;
/**
* Combines two extractors which will be executed one after each other.
*
* @param <FROM>
* The input type of the first extractor.
* @param <OVER>
* The output type of the first and the input type of the second
* extractor.
* @param <TO>
* The output type of the second extractor and the output type of the
* over all extraction.
*/
@Internal
public class ConcatenatedExtract<FROM, OVER, TO> implements Extractor<FROM, TO> {
private static final long serialVersionUID = -7807197760725651752L;
private Extractor<FROM, OVER> e1;
private Extractor<OVER, TO> e2;
/**
* Combines two extractors which will be executed one after each other.
*
* @param e1
* First extractor: This extractor gets applied to the input data
* first. Its output as then passed as input to the second
* extractor.
* @param e2
* Second extractor: This extractor gets the output of the first
* extractor as input. Its output is then the result of the over
* all extraction.
*/
public ConcatenatedExtract(Extractor<FROM, OVER> e1, Extractor<OVER, TO> e2) {
this.e1 = e1;
this.e2 = e2;
}
@Override
public TO extract(FROM in) {
return e2.extract(e1.extract(in));
}
public <OUT> ConcatenatedExtract<FROM, TO, OUT> add(Extractor<TO, OUT> e3) {
return new ConcatenatedExtract<FROM, TO, OUT>(this, e3);
}
}