Package adams.flow.transformer

Class FileTailer

  • All Implemented Interfaces:
    AdditionalInformationHandler, CleanUpHandler, Destroyable, GlobalInfoSupporter, LoggingLevelHandler, LoggingSupporter, OptionHandler, QuickInfoSupporter, ShallowCopySupporter<Actor>, SizeOfHandler, Stoppable, StoppableWithFeedback, VariablesInspectionHandler, VariableChangeListener, Actor, ErrorHandler, InputConsumer, OutputProducer, Serializable, Comparable
    public class FileTailer
extends AbstractTransformer
    Monitors a text file for data being appended, e.g., log files.

    Input/output:
    - accepts:
       java.lang.String
       java.io.File
    - generates:
       java.lang.String


    -logging-level <OFF|SEVERE|WARNING|INFO|CONFIG|FINE|FINER|FINEST> (property: loggingLevel)
    The logging level for outputting errors and debugging output.
    default: WARNING
 
    -name <java.lang.String> (property: name)
    The name of the actor.
    default: FileTailer
 
    -annotation <adams.core.base.BaseAnnotation> (property: annotations)
    The annotations to attach to this actor.
    default: 
 
    -skip <boolean> (property: skip)
    If set to true, transformation is skipped and the input token is just forwarded 
    as it is.
    default: false
 
    -stop-flow-on-error <boolean> (property: stopFlowOnError)
    If set to true, the flow execution at this level gets stopped in case this 
    actor encounters an error; the error gets propagated; useful for critical 
    actors.
    default: false
 
    -silent <boolean> (property: silent)
    If enabled, then no errors are output in the console; Note: the enclosing 
    actor handler must have this enabled as well.
    default: false
 
    -end <boolean> (property: end)
    If enabled, will start monitoring from the end of the file, otherwise the 
    start.
    default: true
 
    -delay <int> (property: delay)
    The delay in milliseconds.
    default: 100
    minimum: 1
    Author:
    FracPete (fracpete at waikato dot ac dot nz)
    See Also:
    Serialized Form

    • Field Detail

      • m_End

        protected boolean m_End
        whether to tail from the end or beginning of file.

      • m_Delay

        protected int m_Delay
        the delay in msec.

      • m_Tailer

        protected transient org.apache.commons.io.input.Tailer m_Tailer
        the tailer instance.

      • m_Queue

        protected List<String> m_Queue
        the queue with the data.

    • Constructor Detail

      • FileTailer

        public FileTailer()

    • Method Detail

      • setEnd

        public void setEnd​(boolean value)
        Sets whether to start from the end or beginning.
        Parameters:
        value - true if from end

      • getEnd

        public boolean getEnd()
        Returns whether to start from the end or beginning.
        Returns:
        true if from end

      • endTipText

        public String endTipText()
        Returns the tip text for this property.
        Returns:
        tip text for this property suitable for displaying in the GUI or for listing the options.

      • setDelay

        public void setDelay​(int value)
        Sets the delay in milliseconds.
        Parameters:
        value - the delay

      • getDelay

        public int getDelay()
        Returns the delay in milliseconds.
        Returns:
        the delay

      • delayTipText

        public String delayTipText()
        Returns the tip text for this property.
        Returns:
        tip text for this property suitable for displaying in the GUI or for listing the options.

      • accepts

        public Class[] accepts()
        Returns the class that the consumer accepts.
        Returns:
        the Class of objects that can be processed

      • generates

        public Class[] generates()
        Returns the class of objects that it generates.
        Returns:
        the Class of the generated tokens

      • doExecute

        protected String doExecute()
        Executes the flow item.
        Specified by:
        doExecute in class AbstractActor
        Returns:
        null if everything is fine, otherwise error message

      • addLine

        public void addLine​(String line)
        Adds the line to the output.
        Parameters:
        line - the line to add