Package org.htmlcleaner

Class XPather

java.lang.Object

org.htmlcleaner.XPather

public class XPather
extends java.lang.Object

Utility for searching cleaned document tree with XPath expressions.

Examples of supported axes:

• //div//a
• //div//a[@id][@class]
• /body/*[1]/@type
• //div[3]//a[@id][@href='r/n4']
• //div[last() >= 4]//./div[position() = last()])[position() > 22]//li[2]//a
• //div[2]/@*[2]
• data(//div//a[@id][@class])
• //p/last()
• //body//div[3][@class]//span[12.2
• data(//a['v' < @id])

Field Summary

Fields

Modifier and Type	Field	Description
private java.lang.String[]	tokenArray

Constructor Summary

Constructors

Constructor	Description
XPather(java.lang.String expression)	Constructor - creates XPather instance with specified XPath expression.

Method Summary

Modifier and Type	Method	Description
private java.util.Collection	evaluateAgainst(java.util.Collection object, int from, int to, boolean isRecursive, int position, int last, boolean isFilterContext, java.util.Collection filterSource)
java.lang.Object[]	evaluateAgainstNode(TagNode node)	Main public method for this class - a way to execute XPath expression against specified TagNode instance.
private java.util.Collection	evaluateFunction(java.util.Collection source, int from, int to, int position, int last, boolean isFilterContext)	Evaluates specified function.
private boolean	evaluateLogic(java.util.Collection first, java.util.Collection second, java.lang.String logicOperator)	Evaluates logic operation on two collections.
private java.util.Collection	filterByCondition(java.util.Collection source, int from, int to)	Filter nodes satisfying the condition
private int	findClosingIndex(int from, int to)
private java.lang.String	flatten(int from, int to)
private java.util.Collection	getElementsByName(java.util.Collection source, int from, int to, boolean isRecursive, boolean isFilterContext)	For the given source collection and specified name, returns collection of subnodes or attribute values.
private boolean	isAtt(java.lang.String token)	Checks if token is attribute (starts with @)
private boolean	isFunctionCall(int from, int to)	Checks if tokens in specified range represents valid function call.
private boolean	isIdentifier(java.lang.String s)	Checks if given string is valid identifier.
private boolean	isToken(java.lang.String token, int index)
private boolean	isValidDouble(java.lang.String s)
private boolean	isValidInteger(java.lang.String s)
private java.util.Collection	singleton(java.lang.Object element)	Creates one-element collection for the specified object.
private void	throwStandardException()
private java.lang.String	toText(java.lang.Object o)

Methods inherited from class java.lang.Object

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

Field Detail

tokenArray

private java.lang.String[] tokenArray

Constructor Detail

XPather

public XPather(java.lang.String expression)

Constructor - creates XPather instance with specified XPath expression.

Parameters:

expression -

Method Detail

evaluateAgainstNode

public java.lang.Object[] evaluateAgainstNode(TagNode node)
                                       throws XPatherException

Main public method for this class - a way to execute XPath expression against specified TagNode instance.

Parameters:

node -

Throws:

XPatherException

throwStandardException

private void throwStandardException()
                             throws XPatherException

Throws:

XPatherException

evaluateAgainst

private java.util.Collection evaluateAgainst(java.util.Collection object,
                                             int from,
                                             int to,
                                             boolean isRecursive,
                                             int position,
                                             int last,
                                             boolean isFilterContext,
                                             java.util.Collection filterSource)
                                      throws XPatherException

Throws:

XPatherException

flatten

private java.lang.String flatten(int from,
                                 int to)

isValidInteger

private boolean isValidInteger(java.lang.String s)

isValidDouble

private boolean isValidDouble(java.lang.String s)

isIdentifier

private boolean isIdentifier(java.lang.String s)

Checks if given string is valid identifier.

Parameters:

s -

isFunctionCall

private boolean isFunctionCall(int from,
                               int to)

Checks if tokens in specified range represents valid function call.

Parameters:

from -

to -

Returns:

True if it is valid function call, false otherwise.

evaluateFunction

private java.util.Collection evaluateFunction(java.util.Collection source,
                                              int from,
                                              int to,
                                              int position,
                                              int last,
                                              boolean isFilterContext)
                                       throws XPatherException

Evaluates specified function. Currently, following XPath functions are supported: last, position, text, count, data

Parameters:

source -

from -

to -

position -

last -

Returns:

Collection as the result of evaluation.

Throws:

XPatherException

filterByCondition

private java.util.Collection filterByCondition(java.util.Collection source,
                                               int from,
                                               int to)
                                        throws XPatherException

Filter nodes satisfying the condition

Parameters:

source -

from -

to -

Throws:

XPatherException

isToken

private boolean isToken(java.lang.String token,
                        int index)

findClosingIndex

private int findClosingIndex(int from,
                             int to)

Parameters:

from -

to -

Returns:

matching closing index in the token array for the current token, or -1 if there is no closing token within expected bounds.

isAtt

private boolean isAtt(java.lang.String token)

Checks if token is attribute (starts with @)

Parameters:

token -

singleton

private java.util.Collection singleton(java.lang.Object element)

Creates one-element collection for the specified object.

Parameters:

element -

getElementsByName

private java.util.Collection getElementsByName(java.util.Collection source,
                                               int from,
                                               int to,
                                               boolean isRecursive,
                                               boolean isFilterContext)
                                        throws XPatherException

For the given source collection and specified name, returns collection of subnodes or attribute values.

Parameters:

source -

from -

to -

isRecursive -

Returns:

Colection of TagNode instances or collection of String instances.

Throws:

XPatherException

evaluateLogic

private boolean evaluateLogic(java.util.Collection first,
                              java.util.Collection second,
                              java.lang.String logicOperator)

Evaluates logic operation on two collections.

Parameters:

first -

second -

logicOperator -

Returns:

Result of logic operation

toText

private java.lang.String toText(java.lang.Object o)