planetj.database.report
Class ColumnFunction

java.lang.Object
  extended byplanetj.database.report.ColumnFunction
All Implemented Interfaces:
java.io.Serializable
Direct Known Subclasses:
ColumnAverage, ColumnCount, ColumnMax, ColumnMin, ColumnSum

public abstract class ColumnFunction
extends java.lang.Object
implements java.io.Serializable

Represents a function that operates on a column of values in a table

See Also:
Serialized Form

Method Summary
abstract  void clear()
          Clears all the previously processed values from the column function
static ColumnFunction getColumnFunction(java.lang.String pToken, java.lang.String pFieldName)
          Gets a ColumnFunction object for the specified token and field name.
 java.lang.String getFieldName()
          Gets the field name identifying the column this ColumnFunction is operating on
 java.lang.String getFunctionToken()
          Gets the function token for this ColumnFunction.
abstract  java.lang.Object getValue()
          Gets the current value of the column function
 void processRow(Row pRow)
          Inputs a new row to the column function
abstract  void processValue(java.lang.Object pValue)
          Inputs a new value to the column function
 
Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Method Detail

clear

public abstract void clear()
Clears all the previously processed values from the column function


getColumnFunction

public static ColumnFunction getColumnFunction(java.lang.String pToken,
                                               java.lang.String pFieldName)
                                        throws DataEngineException
Gets a ColumnFunction object for the specified token and field name.

Parameters:
pToken - A token defined in the ColumnFunctionToken class
pFieldName - A field name identifying the column on which the ColumnFunction object will operate
Throws:
DataEngineException

getFieldName

public java.lang.String getFieldName()
Gets the field name identifying the column this ColumnFunction is operating on


getFunctionToken

public java.lang.String getFunctionToken()
Gets the function token for this ColumnFunction. The token should be a constant defined in the ColumnFunctionToken class.


getValue

public abstract java.lang.Object getValue()
Gets the current value of the column function


processRow

public void processRow(Row pRow)
                throws DataEngineException
Inputs a new row to the column function

Throws:
DataEngineException

processValue

public abstract void processValue(java.lang.Object pValue)
                           throws DataEngineException
Inputs a new value to the column function

Throws:
DataEngineException