Interface Filter

All Superinterfaces:

Transformer

Functional Interface:

This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.

@FunctionalInterface
public interface Filter
extends Transformer

View transformer which filters out entries which don't belong. Implementations only need to implement the isAllowed method.

See Also:

• View.viewFiltered

Method Summary

Modifier and Type	Method	Description
default byte[]	inverseTransformValue(byte[] tvalue, byte[] key, byte[] tkey)	Calls the isAllowed method.
boolean	isAllowed(byte[] key, byte[] value)	Return true if the given key and value are not to be filtered out.
default byte[]	transformValue(byte[] value, byte[] key, byte[] tkey)	Calls the isAllowed method.

Methods inherited from interface Transformer

inverseTransformKey, inverseTransformKeyGt, inverseTransformKeyLt, requireValue, transformedComparator, transformedOrdering, transformKey, transformValue

Modifier and Type	Method	Description
default byte[]	inverseTransformKey(byte[] tkey)	Apply an inverse transformation of the given key, if supported.
default byte[]	inverseTransformKeyGt(byte[] tkey)	Apply an inverse transformation of the given key, strictly greater than the one given.
default byte[]	inverseTransformKeyLt(byte[] tkey)	Apply an inverse transformation of the given key, strictly less than the one given.
default Boolean	requireValue()	Returns true by default, indicating that the transform methods always require a value instance to be provided.
default Comparator<byte[]>	transformedComparator(Comparator<byte[]> original)	Returns the view comparator, after transformation.
default Ordering	transformedOrdering(Ordering original)	Returns the natural ordering of keys, after they have been transformed.
default byte[]	transformKey(Cursor cursor)	Transform or filter out the given key.
default byte[]	transformValue(Cursor cursor, byte[] tkey)	Transform or filter out the given value.

Method Details

isAllowed

boolean isAllowed(byte[] key,
 byte[] value)
           throws IOException

Return true if the given key and value are not to be filtered out.

Throws:

IOException

transformValue

default byte[] transformValue(byte[] value,
 byte[] key,
 byte[] tkey)
                       throws IOException

Calls the isAllowed method.

Specified by:

transformValue in interface Transformer

Parameters:

value - nullable value to transform

key - non-null untransformed key associated with the value

tkey - non-null transformed key associated with the value

Returns:

transformed value or null to discard entry

Throws:

IOException

inverseTransformValue

default byte[] inverseTransformValue(byte[] tvalue,
 byte[] key,
 byte[] tkey)
                              throws IOException,
ViewConstraintException

Calls the isAllowed method.

Specified by:

inverseTransformValue in interface Transformer

Parameters:

tvalue - nullable value to transform

key - non-null untransformed key associated with the value

tkey - non-null transformed key associated with the value

Returns:

inverse transformed value, or null to delete the value

Throws:

ViewConstraintException - if inverse transformation of given value is not supported

IOException