/*
* 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.kafka.streams.kstream.internals;
import org.apache.kafka.streams.kstream.KeyValueMapper;
import org.apache.kafka.streams.kstream.ValueJoiner;
import org.apache.kafka.streams.processor.ProcessorContext;
class KTableKTableJoinValueGetter<K1, V1, K2, V2, R> implements KTableValueGetter<K1, R> {
private final KTableValueGetter<K1, V1> valueGetter1;
private final KTableValueGetter<K2, V2> valueGetter2;
private final ValueJoiner<? super V1, ? super V2, ? extends R> joiner;
private final KeyValueMapper<K1, V1, K2> keyValueMapper;
public KTableKTableJoinValueGetter(final KTableValueGetter<K1, V1> valueGetter1,
final KTableValueGetter<K2, V2> valueGetter2,
final ValueJoiner<? super V1, ? super V2, ? extends R> joiner,
final KeyValueMapper<K1, V1, K2> keyValueMapper) {
this.valueGetter1 = valueGetter1;
this.valueGetter2 = valueGetter2;
this.joiner = joiner;
this.keyValueMapper = keyValueMapper;
}
@Override
public void init(ProcessorContext context) {
valueGetter1.init(context);
valueGetter2.init(context);
}
@Override
public R get(K1 key) {
R newValue = null;
V1 value1 = valueGetter1.get(key);
if (value1 != null) {
V2 value2 = valueGetter2.get(keyValueMapper.apply(key, value1));
if (value2 != null) {
newValue = joiner.apply(value1, value2);
}
}
return newValue;
}
}