org.jfree.report.function
Class CountDistinctFunction

java.lang.Object
  org.jfree.report.function.AbstractFunction
      org.jfree.report.function.CountDistinctFunction

All Implemented Interfaces:

java.lang.Cloneable, java.util.EventListener, Expression, Function, ReportListener, java.io.Serializable

public class CountDistinctFunction

extends AbstractFunction

implements java.io.Serializable

Counts the distinct occurences of an certain value of an column. This functionality is similiar to the SQL distinct() function.

Author:

Thomas Morgner

See Also:

Serialized Form

Field Summary

static java.lang.String	FIELD_PROPERTY Literal text for the 'field' property.
static java.lang.String	GROUP_PROPERTY Literal text for the 'group' property.

Fields inherited from interface org.jfree.report.function.Expression

AUTOACTIVATE_PROPERTY

Constructor Summary

CountDistinctFunction()
DefaultConstructor.

Method Summary

java.lang.String	getField() Returns the field used by the function.
java.lang.String	getGroup() Returns the group name.
java.lang.Object	getValue() Return the number of distint values for the given column.
void	groupStarted(ReportEvent event) Receives notification that a group has started.
void	itemsAdvanced(ReportEvent event) Receives notification that a row of data is being processed.
void	reportInitialized(ReportEvent event) Receives notification that report generation initializes the current run.
void	setField(java.lang.String field) Sets the field name for the function.
void	setGroup(java.lang.String name) Sets the group name.

Methods inherited from class org.jfree.report.function.AbstractFunction

clone, getDataRow, getDependencyLevel, getInstance, getName, getProperties, getProperty, getProperty, groupFinished, initialize, isActive, itemsFinished, itemsStarted, reportDone, reportFinished, reportStarted, setDataRow, setDependencyLevel, setName, setProperties, setProperty

Methods inherited from class java.lang.Object

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

Field Detail

GROUP_PROPERTY

public static final java.lang.String GROUP_PROPERTY

Literal text for the 'group' property.

See Also:

Constant Field Values

FIELD_PROPERTY

public static final java.lang.String FIELD_PROPERTY

Literal text for the 'field' property.

See Also:

Constant Field Values

Constructor Detail

CountDistinctFunction

public CountDistinctFunction()

DefaultConstructor.

Method Detail

getGroup

public java.lang.String getGroup()

Returns the group name.

Returns:

The group name.

setGroup

public void setGroup(java.lang.String name)

Sets the group name.

If a group is defined, the running total is reset to zero at the start of every instance of this group.

Parameters:

name - the group name (null permitted).

getField

public java.lang.String getField()

Returns the field used by the function.

The field name corresponds to a column name in the report's TableModel.

Returns:

The field name.

setField

public void setField(java.lang.String field)

Sets the field name for the function.

The field name corresponds to a column name in the report's TableModel.

Parameters:

field - the field name (null not permitted).

reportInitialized

public void reportInitialized(ReportEvent event)

Receives notification that report generation initializes the current run.

The event carries a ReportState.Started state. Use this to initialize the report.

Specified by:

reportInitialized in interface ReportListener

Overrides:

reportInitialized in class AbstractFunction

Parameters:

event - The event.

groupStarted

public void groupStarted(ReportEvent event)

Receives notification that a group has started.

Specified by:

groupStarted in interface ReportListener

Overrides:

groupStarted in class AbstractFunction

Parameters:

event - the event.

itemsAdvanced

public void itemsAdvanced(ReportEvent event)

Receives notification that a row of data is being processed.

Specified by:

itemsAdvanced in interface ReportListener

Overrides:

itemsAdvanced in class AbstractFunction

Parameters:

event - the event.

getValue

public java.lang.Object getValue()

Return the number of distint values for the given column.

Specified by:

getValue in interface Expression

Returns:

the value of the function.