Package weka.knowledgeflow

Class Data

  • All Implemented Interfaces:
    java.io.Serializable
    public class Data
extends java.lang.Object
implements java.io.Serializable

    Class for encapsulating data to be transferred between Knowledge Flow steps over a particular connection type. Typical usage involves constructing a Data object with a given connection name and then setting one or more pieces of "payload" data to encapsulate. Usually there is a primary payload that is associated with the connection name itself (there is a constructor that takes both the connection name and the primary payload data). Further auxiliary data items can be added via the setPayloadElement() method.

    Standard connection types are defined as constants in the StepManager class. There is nothing to prevent clients from using their own connection types (as these are just string identifiers).

    Typical usage in a client step (transferring an training instances object):

         Instances train = ...
     Data myData = new Data(StepManager.CON_TRAININGSET, train);
     getStepManager().outputData(myData);
    Version:
    $Revision: $
    Author:
    mhall{[at]}pentaho{[dot]}com
    See Also:
    Serialized Form

    • Constructor Summary

      Constructors 
      Constructor Description
      Data()
      Empty constructor - no connection name; no payload
      Data​(java.lang.String connectionName)
      Construct a Data object with just a connection name
      Data​(java.lang.String connectionName, java.lang.Object primaryPayload)
      Construct a Data object with a connection name and a primary payload object to associate with the connection name

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      void clearPayload()
      Clear all payload elements from this Data object
      java.lang.String getConnectionName()
      Get the connection name associated with this Data object
      <T> T getPayloadElement​(java.lang.String name)
      Get a payload element from this Data object.
      <T> T getPayloadElement​(java.lang.String name, T defaultValue)
      Get a payload element from this Data object.
      <T> T getPrimaryPayload()
      Get the primary payload of this data object (i.e.
      Step getSourceStep()
      Get the source step producing this Data object
      boolean isIncremental()
      Return true if the connection specified for this data object is incremental
      void setConnectionName​(java.lang.String name)
      Set the connection name for this Data object
      void setPayloadElement​(java.lang.String name, java.lang.Object value)
      Set a payload element to encapsulate in this Data object.
      void setSourceStep​(Step sourceStep)
      Set the source step of producing this Data object

      • Methods inherited from class java.lang.Object

        equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Constructor Detail

      • Data

        public Data()
        Empty constructor - no connection name; no payload

      • Data

        public Data​(java.lang.String connectionName)
        Construct a Data object with just a connection name
        Parameters:
        connectionName - the connection name

      • Data

        public Data​(java.lang.String connectionName,
            java.lang.Object primaryPayload)
        Construct a Data object with a connection name and a primary payload object to associate with the connection name
        Parameters:
        connectionName - connection name
        primaryPayload - primary payload object (i.e. is keyed against the connection name)

    • Method Detail

      • setSourceStep

        public void setSourceStep​(Step sourceStep)
        Set the source step of producing this Data object
        Parameters:
        sourceStep - the source step

      • getSourceStep

        public Step getSourceStep()
        Get the source step producing this Data object
        Returns:
        the source step producing the data object

      • setConnectionName

        public void setConnectionName​(java.lang.String name)
        Set the connection name for this Data object
        Parameters:
        name - the name of the connection

      • getConnectionName

        public java.lang.String getConnectionName()
        Get the connection name associated with this Data object
        Returns:
        the connection name

      • getPrimaryPayload

        public <T> T getPrimaryPayload()
        Get the primary payload of this data object (i.e. the data associated with the connection name)
        Type Parameters:
        T - the type of the primary payload
        Returns:
        the primary payload data (or null if there is no data associated with the connection)

      • getPayloadElement

        public <T> T getPayloadElement​(java.lang.String name)
        Get a payload element from this Data object. Standard payload element names (keys) can be found as constants defined in the StepManager class.
        Parameters:
        name - the name of the payload element to get
        Returns:
        the named payload element, or null if it does not exist in this Data object

      • getPayloadElement

        public <T> T getPayloadElement​(java.lang.String name,
                               T defaultValue)
        Get a payload element from this Data object. Standard payload element names (keys) can be found as constants defined in the StepManager class.
        Type Parameters:
        T - the type of the payload element to get
        Parameters:
        name - the name of the payload element to get
        defaultValue - a default value if the named element does not exist
        Returns:
        the payload element, or the supplied default value.

      • setPayloadElement

        public void setPayloadElement​(java.lang.String name,
                              java.lang.Object value)
        Set a payload element to encapsulate in this Data object. Standard payload element names (keys) can be found as constants defined in the StepManager class.
        Parameters:
        name - the name of the payload element to encapsulate
        value - the value of the payload element

      • clearPayload

        public void clearPayload()
        Clear all payload elements from this Data object

      • isIncremental

        public boolean isIncremental()
        Return true if the connection specified for this data object is incremental
        Returns:
        true if the connection for this data object is incremental