static Properties getStreamsConfig(final String[] args) throws IOException {
        final Properties props = new Properties();
        if (args != null && args.length > 0) {
            try (final FileInputStream fis = new FileInputStream(args[0])) {
                props.load(fis);
            }
            if (args.length > 1) {
                System.out.println("Warning: Some command line arguments were ignored. This demo only accepts an optional configuration file.");
            }
        }
        props.putIfAbsent(StreamsConfig.APPLICATION_ID_CONFIG, "streams-wordcount");
        props.putIfAbsent(StreamsConfig.BOOTSTRAP_SERVERS_CONFIG, "localhost:9092");
        props.putIfAbsent(StreamsConfig.STATESTORE_CACHE_MAX_BYTES_CONFIG, 0);
        props.putIfAbsent(StreamsConfig.DEFAULT_KEY_SERDE_CLASS_CONFIG, Serdes.StringSerde.class);
        props.putIfAbsent(StreamsConfig.DEFAULT_VALUE_SERDE_CLASS_CONFIG, Serdes.StringSerde.class);

        // setting offset reset to earliest so that we can re-run the demo code with the same pre-loaded data
        // Note: To re-run the demo, you need to use the offset reset tool:
        // https://cwiki.apache.org/confluence/display/KAFKA/Kafka+Streams+Application+Reset+Tool
        props.putIfAbsent(ConsumerConfig.AUTO_OFFSET_RESET_CONFIG, "earliest");
        return props;
    }
Demonstrates, using the high-level KStream DSL, how to implement the WordCount program
that computes a simple word occurrence histogram from an input text.
<p>
In this example, the input stream reads from a topic named "streams-plaintext-input", where the values of messages
represent lines of text; and the histogram output is written to topic "streams-wordcount-output" where each record
is an updated count of a single word.
<p>
Before running this example you must create the input topic and the output topic (e.g. via
{@code bin/kafka-topics.sh --create ...}), and write some data to the input topic (e.g. via
{@code bin/kafka-console-producer.sh}). Otherwise you won't see any data arriving in the output topic.
streams/examples/src/main/java/org/apache/kafka/streams/examples/wordcount/WordCountDemo.java