Services or capabilities described in Amazon Web Services documentation might vary by Region. To see the differences applicable to the China Regions, see Getting Started with Amazon Web Services in China (PDF).

Amazon Managed Service for Apache Flink was previously known as Amazon Kinesis Data Analytics for Apache Flink.

Transforming data using operators in Managed Service for Apache Flink with the DataStream API

To transform incoming data in a Managed Service for Apache Flink, you use an Apache Flink operator. An Apache Flink operator transforms one or more data streams into a new data stream. The new data stream contains modified data from the original data stream. Apache Flink provides more than 25 pre-built stream processing operators. For more information, see Operators in the Apache Flink Documentation.

Transform operators

The following is an example of a simple text transformation on one of the fields of a JSON data stream.

This code creates a transformed data stream. The new data stream has the same data as the original stream, with the string " Company" appended to the contents of the TICKER field.

DataStream<ObjectNode> output = input.map(
    new MapFunction<ObjectNode, ObjectNode>() {
        @Override
        public ObjectNode map(ObjectNode value) throws Exception {
            return value.put("TICKER", value.get("TICKER").asText() + " Company");
        }
    }
);

Aggregation operators

The following is an example of an aggregation operator. The code creates an aggregated data stream. The operator creates a 5-second tumbling window and returns the sum of the PRICE values for the records in the window with the same TICKER value.

DataStream<ObjectNode> output = input.keyBy(node -> node.get("TICKER").asText())
    .window(TumblingProcessingTimeWindows.of(Time.seconds(5)))
    .reduce((node1, node2) -> {
        double priceTotal = node1.get("PRICE").asDouble() + node2.get("PRICE").asDouble();
        node1.replace("PRICE", JsonNodeFactory.instance.numberNode(priceTotal));
    return node1;
});

For more code examples, see Examples.