org.htmlunit.xpath.objects

Class XString

java.lang.Object

org.htmlunit.xpath.Expression

org.htmlunit.xpath.objects.XObject

org.htmlunit.xpath.objects.XString

All Implemented Interfaces:

SourceLocator, ExpressionNode, XPathVisitable

public class XString
extends XObject

This class represents an XPath string object, and is capable of converting the string to other types, such as a number.

Field Summary

Fields

Modifier and Type	Field and Description
static XString	EMPTYSTRING Empty string XString object

Fields inherited from class org.htmlunit.xpath.objects.XObject

CLASS_BOOLEAN, CLASS_NODESET, CLASS_NULL, CLASS_NUMBER, CLASS_RTREEFRAG, CLASS_STRING, CLASS_UNKNOWN, m_obj

Constructor Summary

Constructors

Constructor and Description
XString(String val) Construct a XNodeSet object.

Method Summary

Modifier and Type	Method and Description
boolean	bool() Cast result object to a boolean.
void	callVisitors(XPathVisitor visitor) This will traverse the hierarchy, calling the visitor for each member.
char	charAt(int index) Returns the character at the specified index.
boolean	equals(Object obj2)
boolean	equals(String obj2) Compares this string to the specified String.
boolean	equals(XObject obj2) Tell if two objects are functionally equal.
boolean	equals(XString obj2) Compares this string to the specified object.
XString	fixWhiteSpace(boolean trimHead, boolean trimTail, boolean doublePunctuationSpaces) Conditionally trim all leading and trailing whitespace in the specified String.
void	getChars(int srcBegin, int srcEnd, char[] dst, int dstBegin) Copies characters from this string into the destination character array.
int	getType() Tell what kind of class this is.
String	getTypeString() Given a request type, return the equivalent string.
boolean	hasString() Tell if this object contains a java String object.
int	indexOf(XString str) Returns the index within this string of the first occurrence of the specified substring.
int	length() Returns the length of this string.
double	num() Cast result object to a number.
boolean	startsWith(XString prefix) Tests if this string starts with the specified prefix.
boolean	startsWith(XString prefix, int toffset) Tests if this string starts with the specified prefix beginning a specified index.
String	str() Cast result object to a string.
XString	substring(int beginIndex) Returns a new string that is a substring of this string.
XString	substring(int beginIndex, int endIndex) Returns a new string that is a substring of this string.
double	toDouble() Convert a string to a double -- Allowed input is in fixed notation ddd.fff.
XString	trim() Removes white space from both ends of this string.
XString	xstr() Cast result object to a string.

Methods inherited from class org.htmlunit.xpath.objects.XObject

boolWithSideEffects, deepEquals, detach, error, error, execute, greaterThan, greaterThanOrEqual, iter, lessThan, lessThanOrEqual, mutableNodeset, nodelist, nodeset, notEquals, numWithSideEffects, object, setObject, toString

Methods inherited from class org.htmlunit.xpath.Expression

asIterator, asNode, assertion, bool, canTraverseOutsideSubtree, error, execute, execute, execute, exprGetParent, exprSetParent, getColumnNumber, getExpressionOwner, getLineNumber, getPublicId, getSystemId, isSameClass, isStableNumber, num

Methods inherited from class java.lang.Object

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

Field Detail

EMPTYSTRING

public static final XString EMPTYSTRING

Empty string XString object

Constructor Detail

XString

public XString(String val)

Construct a XNodeSet object.

Parameters:

val - String object this will wrap.

Method Detail

getType

public int getType()

Tell what kind of class this is.

Overrides:

getType in class XObject

Returns:

CLASS_UNKNOWN

getTypeString

public String getTypeString()

Given a request type, return the equivalent string. For diagnostic purposes.

Overrides:

getTypeString in class XObject

Returns:

type string "#UNKNOWN" + object class name

hasString

public boolean hasString()

Tell if this object contains a java String object.

Returns:

true if this XMLString can return a string without creating one.

num

public double num()

Cast result object to a number. Always issues an error.

Overrides:

num in class XObject

Returns:

0.0

toDouble

public double toDouble()

Convert a string to a double -- Allowed input is in fixed notation ddd.fff.

Returns:

A double value representation of the string, or return Double.NaN if the string can not be converted.

bool

public boolean bool()

Cast result object to a boolean. Always issues an error.

Overrides:

bool in class XObject

Returns:

false

xstr

public XString xstr()

Cast result object to a string.

Overrides:

xstr in class XObject

Returns:

The string this wraps or the empty string if null

str

public String str()

Cast result object to a string.

Overrides:

str in class XObject

Returns:

The object as a string

length

public int length()

Returns the length of this string.

Returns:

the length of the sequence of characters represented by this object.

charAt

public char charAt(int index)

Returns the character at the specified index. An index ranges from 0 to length() - 1. The first character of the sequence is at index 0, the next at index 1, and so on, as for array indexing.

Parameters:

index - the index of the character.

Returns:

the character at the specified index of this string. The first character is at index 0.

Throws:

IndexOutOfBoundsException - if the index argument is negative or not less than the length of this string.

getChars

public void getChars(int srcBegin,
                     int srcEnd,
                     char[] dst,
                     int dstBegin)

Copies characters from this string into the destination character array.

Parameters:

srcBegin - index of the first character in the string to copy.

srcEnd - index after the last character in the string to copy.

dst - the destination array.

dstBegin - the start offset in the destination array.

Throws:

IndexOutOfBoundsException - If any of the following is true:

• srcBegin is negative.
• srcBegin is greater than srcEnd
• srcEnd is greater than the length of this string
• dstBegin is negative
• dstBegin+(srcEnd-srcBegin) is larger than dst.length

NullPointerException - if dst is null

equals

public boolean equals(XObject obj2)

Tell if two objects are functionally equal.

Overrides:

equals in class XObject

Parameters:

obj2 - Object to compare this to

Returns:

True if this object is equal to the given object

equals

public boolean equals(String obj2)

Compares this string to the specified String. The result is true if and only if the argument is not null and is a String object that represents the same sequence of characters as this object.

Parameters:

obj2 - the object to compare this String against.

Returns:

true if the Strings are equal; false otherwise.

See Also:

String.compareTo(java.lang.String), String.equalsIgnoreCase(java.lang.String)

equals

public boolean equals(XString obj2)

Compares this string to the specified object. The result is true if and only if the argument is not null and is a String object that represents the same sequence of characters as this object.

Parameters:

obj2 - the object to compare this String against.

Returns:

true if the String are equal; false otherwise.

See Also:

String.compareTo(java.lang.String), String.equalsIgnoreCase(java.lang.String)

equals

public boolean equals(Object obj2)

Overrides:

equals in class Object

startsWith

public boolean startsWith(XString prefix,
                          int toffset)

Tests if this string starts with the specified prefix beginning a specified index.

Parameters:

prefix - the prefix.

toffset - where to begin looking in the string.

Returns:

true if the character sequence represented by the argument is a prefix of the substring of this object starting at index toffset; false otherwise. The result is false if toffset is negative or greater than the length of this String object; otherwise the result is the same as the result of the expression

         this.subString(toffset).startsWith(prefix)
         

Throws:

NullPointerException - if prefix is null.

startsWith

public boolean startsWith(XString prefix)

Tests if this string starts with the specified prefix.

Parameters:

prefix - the prefix.

Returns:

true if the character sequence represented by the argument is a prefix of the character sequence represented by this string; false otherwise. Note also that true will be returned if the argument is an empty string or is equal to this String object as determined by the equals(Object) method.

Throws:

NullPointerException - if prefix is null.

indexOf

public int indexOf(XString str)

Returns the index within this string of the first occurrence of the specified substring. The integer returned is the smallest value k such that:

 this.startsWith(str, k)
 

is true.

Parameters:

str - any string.

Returns:

if the string argument occurs as a substring within this object, then the index of the first character of the first such substring is returned; if it does not occur as a substring, -1 is returned.

Throws:

NullPointerException - if str is null.

substring

public XString substring(int beginIndex)

Returns a new string that is a substring of this string. The substring begins with the character at the specified index and extends to the end of this string.

Examples:

 "unhappy".substring(2) returns "happy"
 "Harbison".substring(3) returns "bison"
 "emptiness".substring(9) returns "" (an empty string)
 

Parameters:

beginIndex - the beginning index, inclusive.

Returns:

the specified substring.

Throws:

IndexOutOfBoundsException - if beginIndex is negative or larger than the length of this String object.

substring

public XString substring(int beginIndex,
                         int endIndex)

Returns a new string that is a substring of this string. The substring begins at the specified beginIndex and extends to the character at index endIndex - 1 . Thus the length of the substring is endIndex-beginIndex.

Parameters:

beginIndex - the beginning index, inclusive.

endIndex - the ending index, exclusive.

Returns:

the specified substring.

Throws:

IndexOutOfBoundsException - if the beginIndex is negative, or endIndex is larger than the length of this String object, or beginIndex is larger than endIndex.

trim

public XString trim()

Removes white space from both ends of this string.

Returns:

this string, with white space removed from the front and end.

fixWhiteSpace

public XString fixWhiteSpace(boolean trimHead,
                             boolean trimTail,
                             boolean doublePunctuationSpaces)

Conditionally trim all leading and trailing whitespace in the specified String. All strings of white space are replaced by a single space character (#x20), except spaces after punctuation which receive double spaces if doublePunctuationSpaces is true. This function may be useful to a formatter, but to get first class results, the formatter should probably do it's own white space handling based on the semantics of the formatting object.

Parameters:

trimHead - Trim leading whitespace?

trimTail - Trim trailing whitespace?

doublePunctuationSpaces - Use double spaces for punctuation?

Returns:

The trimmed string.

callVisitors

public void callVisitors(XPathVisitor visitor)

This will traverse the hierarchy, calling the visitor for each member. If the called visitor method returns false, the subtree should not be called.

Specified by:

callVisitors in interface XPathVisitable

Overrides:

callVisitors in class XObject

Parameters:

visitor - The visitor whose appropriate method will be called.