weka.gui.streams

## Class InstanceJoiner

- java.lang.Object
- - weka.gui.streams.InstanceJoiner

- All Implemented Interfaces:
    java.io.Serializable, java.util.EventListener, InstanceProducer, SerialInstanceListener

      public class InstanceJoiner
      extends java.lang.Object
      implements java.io.Serializable, InstanceProducer, SerialInstanceListener

  A bean that joins two streams of instances into one.
  Version:
    $Revision: 10222 $
  Author:
    Len Trigg (trigg@cs.waikato.ac.nz)
  See Also:
    Serialized Form

- - ### Constructor Summary

    Constructors
    Constructor and Description
    `InstanceJoiner()` Setup the initial states of the member variables

  - ### Method Summary

    Methods
    Modifier and Type | Method and Description
    --- | ---
    `void` | `addInstanceListener(InstanceListener ipl)`
    `void` | `batchFinished()` Signify that this batch of input to the filter is finished.
    `boolean` | `getDebug()`
    `boolean` | `input(Instance instance)`
    `boolean` | `inputFormat(Instances instanceInfo)` Sets the format of the input instances.
    `void` | `instanceProduced(InstanceEvent e)`
    `Instances` | `outputFormat()` Gets the format of the output instances.
    `Instance` | `outputPeek()` Output an instance after filtering but do not remove from the output queue.
    `void` | `removeInstanceListener(InstanceListener ipl)`
    `void` | `secondInstanceProduced(InstanceEvent e)`
    `void` | `setDebug(boolean debug)`

    - ### Methods inherited from class java.lang.Object

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

- - ### Constructor Detail

    - #### InstanceJoiner

          public InstanceJoiner()

      Setup the initial states of the member variables

  - ### Method Detail

    - #### inputFormat

          public boolean inputFormat(Instances instanceInfo)

      Sets the format of the input instances. If the filter is able to determine the output format before seeing any input instances, it does so here. This default implementation assumes the output format is determined when batchFinished() is called.
      Parameters:
        `instanceInfo` - an Instances object containing the input instance structure (any instances contained in the object are ignored - only the structure is required).
      Returns:
        true if the outputFormat may be collected immediately

    - #### outputFormat

          public Instances outputFormat()
                                 throws java.lang.Exception

      Gets the format of the output instances. This should only be called after input() or batchFinished() has returned true.
      Specified by:
        `outputFormat` in interface `InstanceProducer`
      Returns:
        an Instances object containing the output instance structure only.
      Throws:
        `java.lang.Exception` - if no input structure has been defined (or the output format hasn't been determined yet)

    - #### input

          public boolean input(Instance instance)
                        throws java.lang.Exception

      Throws:
        `java.lang.Exception`

    - #### batchFinished

          public void batchFinished()
                             throws java.lang.Exception

      Signify that this batch of input to the filter is finished. If the filter requires all instances prior to filtering, output() may now be called to retrieve the filtered instances. Any subsequent instances filtered should be filtered based on setting obtained from the first batch (unless the inputFormat has been re-assigned or new options have been set). This default implementation assumes all instance processing occurs during inputFormat() and input().
      Throws:
        `java.lang.Exception` - if no input structure has been defined

    - #### outputPeek

          public Instance outputPeek()
                              throws java.lang.Exception

      Output an instance after filtering but do not remove from the output queue.
      Specified by:
        `outputPeek` in interface `InstanceProducer`
      Returns:
        the instance that has most recently been filtered (or null if the queue is empty).
      Throws:
        `java.lang.Exception` - if no input structure has been defined

    - #### setDebug

          public void setDebug(boolean debug)

    - #### getDebug

          public boolean getDebug()

    - #### addInstanceListener

          public void addInstanceListener(InstanceListener ipl)

      Specified by:
        `addInstanceListener` in interface `InstanceProducer`

    - #### removeInstanceListener

          public void removeInstanceListener(InstanceListener ipl)

      Specified by:
        `removeInstanceListener` in interface `InstanceProducer`

    - #### instanceProduced

          public void instanceProduced(InstanceEvent e)

    - #### secondInstanceProduced

          public void secondInstanceProduced(InstanceEvent e)

      Specified by:
        `secondInstanceProduced` in interface `SerialInstanceListener`