/** * 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 kafka.producer /** * A partitioner controls the mapping between user-provided keys and kafka partitions. Users can implement a custom * partitioner to change this mapping. * * Implementations will be constructed via reflection and are required to have a constructor that takes a single * VerifiableProperties instance--this allows passing configuration properties into the partitioner implementation. */ trait Partitioner { /** * Uses the key to calculate a partition bucket id for routing * the data to the appropriate broker partition * @return an integer between 0 and numPartitions-1 */ def partition(key: Any, numPartitions: Int): Int }