Designing a simple stream process does not require more than writing some XML declaration and executing that XML with the stream-runner as shown in the following figure:

The simple example presented below, defines a single process that reads from a CSV stream and prints out the data items to standard output:

    <stream id="firstStream" class="stream.io.CsvStream"
            url="http://www.jwall.org/streams/sample-stream.csv" />

    <process input="firstStream">
        <PrintData />

The stream-runner required to execute this stream is a simple executable Java archive available for download: stream-runner.jar.

Running the Stream Process

The simple process defined above can be run by

 # java -jar stream-runner.jar first-process.xml

The process will simply read the stream in CSV-format and execute the processor PrintData for each item obtained from the stream.