uk.ac.sheffield.jast.filter

Class NodeFilter

java.lang.Object

uk.ac.sheffield.jast.filter.Filter

uk.ac.sheffield.jast.filter.MaskFilter

uk.ac.sheffield.jast.filter.NodeFilter

public class NodeFilter
extends MaskFilter

NodeFilter is a simple filter for selecting different types of XML content. A NodeFilter stores a bit-mask representing all the content types that are accepted by the Filter. A mask consisting of the bitwise-OR of several content types will accept Content nodes of all of those types. See the class Content for a complete list of predefined content types. These are provided as public constants, for ease of use in client programs.

NodeFilter has an accept(Content) method, which returns true, if the type of the Content is accepted by the NodeFilter. Internally, filtering is performed by testing the bit-pattern of each content-type value against the NodeFilter's internal bit-mask. A bit-pattern is accepted if it is unchanged by bitwise-AND with the NodeFilter's mask.

Version:

2.5

Author:

Anthony J H Simons

Field Summary

Fields inherited from class uk.ac.sheffield.jast.filter.MaskFilter

mask

Fields inherited from class uk.ac.sheffield.jast.filter.Filter

ALLCONTENT, NAMENODES, PARENTNODES, PROPERTYNODES, VALUENODES, XPATHNODES, XPATHTEXT

Constructor Summary

Constructors

Constructor and Description
NodeFilter() Creates a NodeFilter that accepts all Content-types.
NodeFilter(int contentType) Creates a NodeFilter with the given bit-mask.

Method Summary

Modifier and Type	Method and Description
Filter	and(Filter other) Creates a Filter that is the logical AND of this and another Filter.
protected NodeFilter	andNodeFilter(NodeFilter other) Creates a Filter that is the logical AND of this and another NodeFilter.
NodeFilter	not() Creates a Filter that is the logical NOT of this NodeFilter.
Filter	or(Filter other) Creates a Filter that is the logical OR of this and another Filter.
protected NodeFilter	orNodeFilter(NodeFilter other) Creates a Filter that is the logical OR of this and another NodeFilter.

Methods inherited from class uk.ac.sheffield.jast.filter.MaskFilter

accept, getMask

Methods inherited from class uk.ac.sheffield.jast.filter.Filter

andIndexFilter, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

NodeFilter

public NodeFilter()

Creates a NodeFilter that accepts all Content-types. This is sometimes used as the default vanilla filter.

NodeFilter

public NodeFilter(int contentType)

Creates a NodeFilter with the given bit-mask. The bit-mask is formed by bitwise-OR of the desired Content-types to accept, for example: Filter f = new NodeFilter(Content.ELEMENT | Content.TEXT);

Parameters:

contentType - a bit-mask representing one or more content types.

Method Detail

not

public NodeFilter not()

Creates a Filter that is the logical NOT of this NodeFilter. Returns a new NodeFilter whose bit-mask is the logical complement of this NodeFilter's mask. This is more efficient than the general approach using an NotFilter.

Overrides:

not in class Filter

Returns:

a new Filter.

and

public Filter and(Filter other)

Creates a Filter that is the logical AND of this and another Filter. The new Filter accepts Content that was accepted both by this, and the other Filter. Constructs the result by double-dispatching, reversing the order of operands. This allows the other Filter to restrict the range of acceptable Content-types, rather than construct another filtering layer using a compound AndFilter.

Overrides:

and in class Filter

Parameters:

other - the other Filter.

Returns:

a new Filter.

or

public Filter or(Filter other)

Creates a Filter that is the logical OR of this and another Filter. The new Filter accepts Content that was accepted either by this, or the other Filter. Constructs the result by double-dispatching, reversing the order of operands. This allows the other Filter to widen the range of acceptable Content-types, rather than construct another filtering layer using a compound OrFilter.

Overrides:

or in class Filter

Parameters:

other - the other Filter.

Returns:

a new Filter.

andNodeFilter

protected NodeFilter andNodeFilter(NodeFilter other)

Creates a Filter that is the logical AND of this and another NodeFilter. Returns a new NodeFilter combining the bit-masks of this and the other NodeFilter using bitwise-AND. This is more efficient than the general approach using an AndFilter.

Overrides:

andNodeFilter in class Filter

Parameters:

other - the other NodeFilter.

Returns:

a new Filter.

orNodeFilter

protected NodeFilter orNodeFilter(NodeFilter other)

Creates a Filter that is the logical OR of this and another NodeFilter. Returns a new NodeFilter combining the bit-masks of this and the other NodeFilter using bitwise-OR. This is more efficient than the general approach using an OrFilter.

Overrides:

orNodeFilter in class Filter

Parameters:

other - the other NodeFilter.

Returns:

a new Filter.