org.apache.kafka.streams.kstream.Predicate Maven / Gradle / Ivy
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* 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,
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* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.kafka.streams.kstream;
import org.apache.kafka.streams.KeyValue;
/**
* The {@code Predicate} interface represents a predicate (boolean-valued function) of a {@link KeyValue} pair.
* This is a stateless record-by-record operation, i.e, {@link #test(Object, Object)} is invoked individually for each
* record of a stream.
*
* @param key type
* @param value type
* @see KStream#filter(Predicate)
* @see KStream#filterNot(Predicate)
* @see KStream#branch(Predicate[])
* @see KTable#filter(Predicate)
* @see KTable#filterNot(Predicate)
*/
public interface Predicate {
/**
* Test if the record with the given key and value satisfies the predicate.
*
* @param key the key of the record
* @param value the value of the record
* @return {@code true} if the {@link KeyValue} pair satisfies the predicate—{@code false} otherwise
*/
boolean test(final K key, final V value);
}