com.antelmann.util
Class OffsetFilter<T>

java.lang.Object
  com.antelmann.util.OffsetFilter<T>

All Implemented Interfaces:

CascadingFilter<T>, Filter<T>, Wrapped<Filter<? super T>>

public class OffsetFilter<T>
extends Object
implements CascadingFilter<T>, Wrapped<Filter<? super T>>

a filter that specifies to a supporting implementation that not all results are desired, but only those starting at a given offset and limited to a given limit. By itself, it maintains a counter that controls the accept method. This filter is supported by JDBCRowStore to limit the returned result; only the inner filter is given to the mapper.

Since:

29.08.2009, 12:09:59

Author:

Holger Antelmann

See Also:

JDBCRowStore.fetch(Filter), JDBCRowStore.fetchStubs(Filter)

Field Summary

Fields inherited from interface com.antelmann.util.Filter

EXCLUDE_ALL_FILTER, INCLUDE_ALL_FILTER

Constructor Summary

OffsetFilter(int limit)

OffsetFilter(int limit, Filter<? super T> innerFilter)

OffsetFilter(int offset, int limit, Filter<? super T> innerFilter)

Method Summary

boolean	accept(T entry) returns true only if the given entry is accepted by this filter
OffsetFilter<T>	createNextFilter() returns a new filter that moves the offset by the limit
Filter<? super T>	getInnerFilter()
int	getLimit()
int	getOffset()
void	resetCounter()
void	setInnerFilter(Filter<? super T> filter)
Filter<? super T>	unwrap() returns the embedded instance that this wrapper encloses

Methods inherited from class java.lang.Object

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

Constructor Detail

OffsetFilter

public OffsetFilter(int limit)

OffsetFilter

public OffsetFilter(int limit,
                    Filter<? super T> innerFilter)

OffsetFilter

public OffsetFilter(int offset,
                    int limit,
                    Filter<? super T> innerFilter)

Parameters:

offset - allows to start not at the first row, but at the given offset (0 means to start at the beginning)

limit - specifies the maximum number of rows to be considered

innerFilter - the actual filter that will be used by the mapper

Method Detail

createNextFilter

public OffsetFilter<T> createNextFilter()

returns a new filter that moves the offset by the limit

getOffset

public int getOffset()

getLimit

public int getLimit()

resetCounter

public void resetCounter()

accept

public boolean accept(T entry)

Description copied from interface: Filter

returns true only if the given entry is accepted by this filter

Specified by:

accept in interface Filter<T>

unwrap

public Filter<? super T> unwrap()

Description copied from interface: Wrapped

returns the embedded instance that this wrapper encloses

Specified by:

unwrap in interface Wrapped<Filter<? super T>>

getInnerFilter

public Filter<? super T> getInnerFilter()

Specified by:

getInnerFilter in interface CascadingFilter<T>

setInnerFilter

public void setInnerFilter(Filter<? super T> filter)

Specified by:

setInnerFilter in interface CascadingFilter<T>