Class Join

  • All Implemented Interfaces:
    java.io.Serializable, BaseStepExtender, Step

    @KFStep(name="Join",
            category="Flow",
            toolTipText="Performs an inner join on two incoming datasets/instance streams (IMPORTANT: assumes that both datasets are sorted in ascending order of the key fields). If data is not sorted then usea Sorter step to sort both into ascending order of the key fields. Does not handle the case wherekeys are not unique in one or both inputs.",
            iconPath="weka/gui/knowledgeflow/icons/Join.gif")
    public class Join
    extends BaseStep
    Step that performs an inner join on one or more key fields from two incoming batch or streaming datasets.
    Version:
    $Revision: $
    Author:
    Mark Hall (mhall{[at]}pentaho{[dot]}com)
    See Also:
    Serialized Form
    • Field Detail

      • KEY_SPEC_SEPARATOR

        public static final java.lang.String KEY_SPEC_SEPARATOR
        Separator used to separate first and second input key specifications
        See Also:
        Constant Field Values
    • Constructor Detail

      • Join

        public Join()
    • Method Detail

      • setKeySpec

        public void setKeySpec​(java.lang.String ks)
        Set the key specification (in internal format - k11,k12,...,k1nKEY_SPEC_SEPARATORk21,k22,...,k2n)
        Parameters:
        ks - the keys specification
      • getKeySpec

        public java.lang.String getKeySpec()
        Get the key specification (in internal format - k11,k12,...,k1nKEY_SPEC_SEPARATORk21,k22,...,k2n)
        Returns:
        the keys specification
      • getConnectedInputNames

        public java.util.List<java.lang.String> getConnectedInputNames()
        Get the names of the connected steps as a list
        Returns:
        the names of the connected steps as a list
      • getFirstInputStructure

        public Instances getFirstInputStructure()
                                         throws WekaException
        Get the Instances structure being produced by the first input
        Returns:
        the Instances structure from the first input
        Throws:
        WekaException - if a problem occurs
      • getSecondInputStructure

        public Instances getSecondInputStructure()
                                          throws WekaException
        Get the Instances structure being produced by the second input
        Returns:
        the Instances structure from the second input
        Throws:
        WekaException - if a problem occurs
      • getIncomingConnectionTypes

        public java.util.List<java.lang.String> getIncomingConnectionTypes()
        Get a list of incoming connection types that this step can accept. Ideally (and if appropriate), this should take into account the state of the step and any existing incoming connections. E.g. a step might be able to accept one (and only one) incoming batch data connection.
        Returns:
        a list of incoming connections that this step can accept given its current state
      • getOutgoingConnectionTypes

        public java.util.List<java.lang.String> getOutgoingConnectionTypes()
        Get a list of outgoing connection types that this step can produce. Ideally (and if appropriate), this should take into account the state of the step and the incoming connections. E.g. depending on what incoming connection is present, a step might be able to produce a trainingSet output, a testSet output or neither, but not both.
        Returns:
        a list of outgoing connections that this step can produce
      • getCustomEditorForStep

        public java.lang.String getCustomEditorForStep()
        Return the fully qualified name of a custom editor component (JComponent) to use for editing the properties of the step. This method can return null, in which case the system will dynamically generate an editor using the GenericObjectEditor
        Specified by:
        getCustomEditorForStep in interface Step
        Overrides:
        getCustomEditorForStep in class BaseStep
        Returns:
        the fully qualified name of a step editor component