自定义分区(Custom)
当Flink提供的所有分区策略都不能满足用户的需求时,我们可以通过使用partitionCustom()方法来自定义分区策略。
1)自定义分区器
public class MyPartitioner implements Partitioner<String> {
@Override
public int partition(String key, int numPartitions) {
return Integer.parseInt(key) % numPartitions;
}
}
2)使用自定义分区
public class PartitionCustomDemo {
public static void main(String[] args) throws Exception {
// StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
StreamExecutionEnvironment env = StreamExecutionEnvironment.createLocalEnvironmentWithWebUI(new Configuration());
env.setParallelism(2);
DataStreamSource<String> socketDS = env.socketTextStream("hadoop102", 7777);
DataStream<String> myDS = socketDS
.partitionCustom(
new MyPartitioner(),
value -> value);
myDS.print();
env.execute();
}
}