如何使用带有特定分区的Apache Flink将数据作为键/值发送到Kafka

import org.apache.flink.api.common.serialization.SimpleStringSchema;
import org.apache.flink.streaming.api.datastream.DataStream;
import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment;
import org.apache.flink.streaming.connectors.kafka.FlinkKafkaProducer;
import org.apache.flink.streaming.connectors.kafka.KafkaSerializationSchema;
import org.apache.kafka.clients.producer.ProducerRecord;

public class FlinkKafkaExample {
    public static void main(String[] args) throws Exception {
        // 设置执行环境
        StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();

        // 创建数据流
        DataStream<String> dataStream = env.fromElements("key1,value1", "key2,value2", "key3,value3");

        // 将数据按照键进行分区
        DataStream<String> partitionedStream = dataStream.keyBy(value -> value.split(",")[0]);

        // 将数据发送到Kafka
        partitionedStream.addSink(new FlinkKafkaProducer<>("localhost:9092", "topic", new SimpleStringSchema()));

        // 执行任务
        env.execute("Flink Kafka Example");
    }
}