weka.experiment
Class DatabaseResultListener

java.lang.Object
  |
  +--weka.experiment.DatabaseUtils
        |
        +--weka.experiment.DatabaseResultListener

All Implemented Interfaces:

ResultListener, java.io.Serializable

Direct Known Subclasses:

DatabaseResultProducer

public class DatabaseResultListener

extends DatabaseUtils

implements ResultListener

DatabaseResultListener takes the results from a ResultProducer and submits them to a central database.

Version:

$Revision: 1.8 $

Author:

Len Trigg (trigg@cs.waikato.ac.nz)

See Also:

Serialized Form

Field Summary

Fields inherited from class weka.experiment.DatabaseUtils

BOOL, BYTE, DATE, DOUBLE, EXP_INDEX_TABLE, EXP_RESULT_COL, EXP_RESULT_PREFIX, EXP_SETUP_COL, EXP_TYPE_COL, FLOAT, INTEGER, LONG, SHORT, STRING

Constructor Summary

DatabaseResultListener()
Sets up the database drivers

Method Summary

void	acceptResult(ResultProducer rp, java.lang.Object[] key, java.lang.Object[] result) Submit the result to the appropriate table of the database
java.lang.String	cacheKeyNameTipText() Returns the tip text for this property
java.lang.String[]	determineColumnConstraints(ResultProducer rp) Determines if there are any constraints (imposed by the destination) on any additional measures produced by resultProducers.
java.lang.String	getCacheKeyName() Get the value of CacheKeyName.
java.lang.String	globalInfo() Returns a string describing this result listener
boolean	isResultRequired(ResultProducer rp, java.lang.Object[] key) Always says a result is required.
void	postProcess(ResultProducer rp) Perform any postprocessing.
void	preProcess(ResultProducer rp) Prepare for the results to be received.
void	setCacheKeyName(java.lang.String newCacheKeyName) Set the value of CacheKeyName.

Methods inherited from class weka.experiment.DatabaseUtils

arrayToString, connectToDatabase, createExperimentIndex, createExperimentIndexEntry, createResultsTable, databaseURLTipText, disconnectFromDatabase, execute, experimentIndexExists, getDatabaseURL, getPassword, getResultFromTable, getResultSet, getResultsTableName, getUsername, isConnected, putResultInTable, setDatabaseURL, setPassword, setUsername, tableExists, typeName

Methods inherited from class java.lang.Object

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

Constructor Detail

DatabaseResultListener

public DatabaseResultListener()
                       throws java.lang.Exception

Sets up the database drivers

Throws:

java.lang.Exception - if an error occurs

Method Detail

globalInfo

public java.lang.String globalInfo()

Returns a string describing this result listener

Returns:

a description of the result listener suitable for displaying in the explorer/experimenter gui

preProcess

public void preProcess(ResultProducer rp)
                throws java.lang.Exception

Prepare for the results to be received.

Specified by:

preProcess in interface ResultListener

Parameters:

rp - the ResultProducer that will generate the results

Throws:

java.lang.Exception - if an error occurs during preprocessing.

postProcess

public void postProcess(ResultProducer rp)
                 throws java.lang.Exception

Perform any postprocessing. When this method is called, it indicates that no more results will be sent that need to be grouped together in any way.

Specified by:

postProcess in interface ResultListener

Parameters:

rp - the ResultProducer that generated the results

Throws:

java.lang.Exception - if an error occurs

determineColumnConstraints

public java.lang.String[] determineColumnConstraints(ResultProducer rp)
                                              throws java.lang.Exception

Determines if there are any constraints (imposed by the destination) on any additional measures produced by resultProducers. Null should be returned if there are NO constraints, otherwise a list of column names should be returned as an array of Strings. In the case of DatabaseResultListener, the structure of an existing database will impose constraints.

Specified by:

determineColumnConstraints in interface ResultListener

Parameters:

rp - the ResultProducer to which the constraints will apply

Returns:

an array of column names to which resutltProducer's results will be restricted.

Throws:

java.lang.Exception - if an error occurs.

acceptResult

public void acceptResult(ResultProducer rp,
                         java.lang.Object[] key,
                         java.lang.Object[] result)
                  throws java.lang.Exception

Submit the result to the appropriate table of the database

Specified by:

acceptResult in interface ResultListener

Parameters:

rp - the ResultProducer that generated the result

key - The key for the results.

result - The actual results.

Throws:

java.lang.Exception - if the result couldn't be sent to the database

isResultRequired

public boolean isResultRequired(ResultProducer rp,
                                java.lang.Object[] key)
                         throws java.lang.Exception

Always says a result is required. If this is the first call, prints out the header for the Database output.

Specified by:

isResultRequired in interface ResultListener

Parameters:

rp - the ResultProducer wanting to generate the result

key - The key for which a result may be needed.

Returns:

true if the result should be calculated.

Throws:

java.lang.Exception - if the database couldn't be queried

cacheKeyNameTipText

public java.lang.String cacheKeyNameTipText()

Returns the tip text for this property

Returns:

tip text for this property suitable for displaying in the explorer/experimenter gui

getCacheKeyName

public java.lang.String getCacheKeyName()

Get the value of CacheKeyName.

Returns:

Value of CacheKeyName.

setCacheKeyName

public void setCacheKeyName(java.lang.String newCacheKeyName)

Set the value of CacheKeyName.

Parameters:

newCacheKeyName - Value to assign to CacheKeyName.