public static void main()

in quickstart-flink/quickstart-apacheflink/apacheflinksql_demo/src/main/java/SocketWindowWordCount.java [40:85]
35 lines of code
4 McCabe index (conditional complexity)

    public static void main(String[] args) throws Exception {

        // the host and the port to connect to
        final String hostname;
        final int port;
        try {
            final ParameterTool params = ParameterTool.fromArgs(args);
            hostname = params.has("hostname") ? params.get("hostname") : "localhost";
            port = params.getInt("port");
        } catch (Exception e) {
            System.err.println(
                    "No port specified. Please run 'SocketWindowWordCount "
                            + "--hostname <hostname> --port <port>', where hostname (localhost by default) "
                            + "and port is the address of the text server");
            System.err.println(
                    "To start a simple text server, run 'netcat -l <port>' and "
                            + "type the input text into the command line");
            return;
        }

        // get the execution environment
        final StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();

        // get input data by connecting to the socket
        DataStream<String> text = env.socketTextStream(hostname, port, "\n");

        // parse the data, group it, window it, and aggregate the counts
        DataStream<WordWithCount> windowCounts =
                text.flatMap(
                                (FlatMapFunction<String, WordWithCount>)
                                        (value, out) -> {
                                            for (String word : value.split("\\s")) {
                                                out.collect(new WordWithCount(word, 1L));
                                            }
                                        },
                                Types.POJO(WordWithCount.class))
                        .keyBy(value -> value.word)
                        .window(TumblingProcessingTimeWindows.of(Time.seconds(5)))
                        .reduce((a, b) -> new WordWithCount(a.word, a.count + b.count))
                        .returns(WordWithCount.class);

        // print the results with a single thread, rather than in parallel
        windowCounts.print().setParallelism(1);

        env.execute("Socket Window WordCount");
    }