CSV protocol handler

The CSV protocol handler parses delimiter separated text lines.

Important: Each CSV-line must end with a newline! Especially important when not using a file for input but e.g. TCPServer transport handler or AMQP/RabbitMQ transport handler.

Options

• delay: Delay of reading in milliseconds (default 0). DEPRECATED: use scheduler.delay instead if not used together with delayeach
• nanodelay: Delay of reading in nanoseconds (default 0).
• delayeach: The number of lines between a delay is used (default 0).
• readfirstline: Should the first line of the file be ignored (e.g. because of header information) (default: true)
• debug: If set to true, some additional thinks are available: (default false)
• dumpEachLine: Dumps lines to the console. if set to 1 each line will be dumped
• measureEachLine: Measures the processing time between n elements that are dumped
• maxLines: Stop processing after n elements are read

• csv.delimiter: The delimiter for splitting the input (Default: , ).

• csv.textDelimiter: The delimiter for strings (Default: ' ). Inside of strings, csv.delimiter is ignored.
• addlinenumber: Adds the line number (starting with 0) to the beginning of the line. Remember to add a proper attribute to the schema! (default false).
• csv.floatingFormatter:If used for writing, each double/float value will be formatted using this formatter (default null). See https://docs.oracle.com/javase/7/docs/api/java/text/DecimalFormat.html
  • This option can also be used for reading.
  • This option can be used together with:
    • decimalseparator: How is the fraction of the number separated. E.g. for reading german formatted doubles you must use something like:   ['csv.floatingformatter','#,##'], ['decimalseparator',',']
    • exponentseparator: typically E
    • groupingseparator: Typically ",". In german this is "."
• csv.numberFormatter: If used for writing, each number other than double/float value will be formatted using this formatter (default null). See https://docs.oracle.com/javase/7/docs/api/java/text/DecimalFormat.html
• csv.trim: Removes leading and trailing whitespaces in each element (default false)
• nullvaluetext: The representation of null values, e.g. '<NULL>' (Default: '')
• csv.writeheading: Writes the schema as header of the csv, if set to true (Default: false)

Example

PQL

input = ACCESS({
                          source='fridgeVibrationCSV',
                          wrapper='GenericPull',
                          transport='File',
                          protocol='CSV',
                          datahandler='Tuple',
                          options=[
                            ['delimiter',','],
                            ['textDelimiter',"'"],
                            ['readfirstline','true'],
                            ['delay','100'],
                            ['filename', 'path to file']
                          ],
                          schema=[
                            ['description','Double']
                          ]                                                
                        }                                            
                      )

CQL

CREATE STREAM csv (symbol String, points Double)   
    WRAPPER 'GenericPush'
    PROTOCOL 'CSV'
    TRANSPORT 'File'
    DATAHANDLER 'Tuple'
    OPTIONS ( 'delimiter' ',', 'textDelimiter' "'", 'readfirstline' 'true', 'delay' '100')