org.apache.xpath.objects

Class XString

public class XString extends XObject implements XMLString

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

UNKNOWN: general

Field Summary
static XStringEMPTYSTRING
Empty string XString object
Constructor Summary
XString(String val)
Construct a XNodeSet object.
Method Summary
booleanbool()
Cast result object to a boolean.
voidcallVisitors(ExpressionOwner owner, XPathVisitor visitor)
charcharAt(int index)
Returns the character at the specified index.
intcompareTo(XMLString xstr)
Compares two strings lexicographically.
intcompareToIgnoreCase(XMLString str)
Compares two strings lexicographically, ignoring case considerations.
XMLStringconcat(String str)
Concatenates the specified string to the end of this string.
voiddispatchAsComment(LexicalHandler lh)
Directly call the comment method on the passed LexicalHandler for the string-value.
voiddispatchCharactersEvents(ContentHandler ch)
Directly call the characters method on the passed ContentHandler for the string-value.
booleanendsWith(String suffix)
Tests if this string ends with the specified suffix.
booleanequals(XObject obj2)
Tell if two objects are functionally equal.
booleanequals(String obj2)
Compares this string to the specified String.
booleanequals(XMLString obj2)
Compares this string to the specified object.
booleanequals(Object obj2)
Compares this string to the specified object.
booleanequalsIgnoreCase(String anotherString)
Compares this String to another String, ignoring case considerations.
XMLStringfixWhiteSpace(boolean trimHead, boolean trimTail, boolean doublePunctuationSpaces)
Conditionally trim all leading and trailing whitespace in the specified String.
voidgetChars(int srcBegin, int srcEnd, char[] dst, int dstBegin)
Copies characters from this string into the destination character array.
intgetType()
Tell that this is a CLASS_STRING.
StringgetTypeString()
Given a request type, return the equivalent string.
inthashCode()
Returns a hashcode for this string.
booleanhasString()
Tell if this object contains a java String object.
intindexOf(int ch)
Returns the index within this string of the first occurrence of the specified character.
intindexOf(int ch, int fromIndex)
Returns the index within this string of the first occurrence of the specified character, starting the search at the specified index.
intindexOf(String str)
Returns the index within this string of the first occurrence of the specified substring.
intindexOf(XMLString str)
Returns the index within this string of the first occurrence of the specified substring.
intindexOf(String str, int fromIndex)
Returns the index within this string of the first occurrence of the specified substring, starting at the specified index.
intlastIndexOf(int ch)
Returns the index within this string of the last occurrence of the specified character.
intlastIndexOf(int ch, int fromIndex)
Returns the index within this string of the last occurrence of the specified character, searching backward starting at the specified index.
intlastIndexOf(String str)
Returns the index within this string of the rightmost occurrence of the specified substring.
intlastIndexOf(String str, int fromIndex)
Returns the index within this string of the last occurrence of the specified substring.
intlength()
Returns the length of this string.
doublenum()
Cast result object to a number.
intrtf(XPathContext support)
Cast result object to a result tree fragment.
booleanstartsWith(String prefix, int toffset)
Tests if this string starts with the specified prefix beginning a specified index.
booleanstartsWith(String prefix)
Tests if this string starts with the specified prefix.
booleanstartsWith(XMLString prefix, int toffset)
Tests if this string starts with the specified prefix beginning a specified index.
booleanstartsWith(XMLString prefix)
Tests if this string starts with the specified prefix.
Stringstr()
Cast result object to a string.
XMLStringsubstring(int beginIndex)
Returns a new string that is a substring of this string.
XMLStringsubstring(int beginIndex, int endIndex)
Returns a new string that is a substring of this string.
doubletoDouble()
Convert a string to a double -- Allowed input is in fixed notation ddd.fff.
XMLStringtoLowerCase(Locale locale)
Converts all of the characters in this String to lower case using the rules of the given Locale.
XMLStringtoLowerCase()
Converts all of the characters in this String to lower case using the rules of the default locale, which is returned by Locale.getDefault.
XMLStringtoUpperCase(Locale locale)
Converts all of the characters in this String to upper case using the rules of the given locale.
XMLStringtoUpperCase()
Converts all of the characters in this String to upper case using the rules of the default locale, which is returned by Locale.getDefault.
XMLStringtrim()
Removes white space from both ends of this string.
XMLStringxstr()
Cast result object to a string.

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

bool

public boolean bool()
Cast result object to a boolean.

Returns: True if the length of this string object is greater than 0.

callVisitors

public void callVisitors(ExpressionOwner owner, XPathVisitor visitor)

See Also: XPathVisitable

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.

compareTo

public int compareTo(XMLString xstr)
Compares two strings lexicographically.

Parameters: xstr the String to be compared.

Returns: the value 0 if the argument string is equal to this string; a value less than 0 if this string is lexicographically less than the string argument; and a value greater than 0 if this string is lexicographically greater than the string argument.

Throws: java.lang.NullPointerException if anotherString is null.

compareToIgnoreCase

public int compareToIgnoreCase(XMLString str)
Compares two strings lexicographically, ignoring case considerations. This method returns an integer whose sign is that of this.toUpperCase().toLowerCase().compareTo( str.toUpperCase().toLowerCase()).

Note that this method does not take locale into account, and will result in an unsatisfactory ordering for certain locales. The java.text package provides collators to allow locale-sensitive ordering.

Parameters: str the String to be compared.

Returns: a negative integer, zero, or a positive integer as the the specified String is greater than, equal to, or less than this String, ignoring case considerations.

Since: 1.2

See Also: java.text.Collator#compare(String, String)

concat

public XMLString concat(String str)
Concatenates the specified string to the end of this string.

Parameters: str the String that is concatenated to the end of this String.

Returns: a string that represents the concatenation of this object's characters followed by the string argument's characters.

Throws: java.lang.NullPointerException if str is null.

dispatchAsComment

public void dispatchAsComment(LexicalHandler lh)
Directly call the comment method on the passed LexicalHandler for the string-value.

Parameters: lh A non-null reference to a LexicalHandler.

Throws: org.xml.sax.SAXException

dispatchCharactersEvents

public void dispatchCharactersEvents(ContentHandler ch)
Directly call the characters method on the passed ContentHandler for the string-value. Multiple calls to the ContentHandler's characters methods may well occur for a single call to this method.

Parameters: ch A non-null reference to a ContentHandler.

Throws: org.xml.sax.SAXException

endsWith

public boolean endsWith(String suffix)
Tests if this string ends with the specified suffix.

Parameters: suffix the suffix.

Returns: true if the character sequence represented by the argument is a suffix of the character sequence represented by this object; false otherwise. Note that the result will be true if the argument is the empty string or is equal to this String object as determined by the equals method.

Throws: java.lang.NullPointerException if suffix is null.

equals

public boolean equals(XObject obj2)
Tell if two objects are functionally equal.

Parameters: obj2 Object to compare this to

Returns: true if the two objects are equal

Throws: javax.xml.transform.TransformerException

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: java.lang.String#compareTo(java.lang.String) java.lang.String#equalsIgnoreCase(java.lang.String)

equals

public boolean equals(XMLString 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: java.lang.String#compareTo(java.lang.String) java.lang.String#equalsIgnoreCase(java.lang.String)

equals

public boolean equals(Object 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: java.lang.String#compareTo(java.lang.String) java.lang.String#equalsIgnoreCase(java.lang.String)

equalsIgnoreCase

public boolean equalsIgnoreCase(String anotherString)
Compares this String to another String, ignoring case considerations. Two strings are considered equal ignoring case if they are of the same length, and corresponding characters in the two strings are equal ignoring case.

Parameters: anotherString the String to compare this String against.

Returns: true if the argument is not null and the Strings are equal, ignoring case; false otherwise.

See Also: equals java.lang.Character#toLowerCase(char) java.lang.Character#toUpperCase(char)

fixWhiteSpace

public XMLString 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.

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:

NullPointerException if dst is null

getType

public int getType()
Tell that this is a CLASS_STRING.

Returns: type CLASS_STRING

getTypeString

public String getTypeString()
Given a request type, return the equivalent string. For diagnostic purposes.

Returns: type string "#STRING"

hashCode

public int hashCode()
Returns a hashcode for this string. The hashcode for a String object is computed as
 s[0]*31^(n-1) + s[1]*31^(n-2) + ... + s[n-1]
 
using int arithmetic, where s[i] is the ith character of the string, n is the length of the string, and ^ indicates exponentiation. (The hash value of the empty string is zero.)

Returns: a hash code value for this object.

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.

indexOf

public int indexOf(int ch)
Returns the index within this string of the first occurrence of the specified character. If a character with value ch occurs in the character sequence represented by this String object, then the index of the first such occurrence is returned -- that is, the smallest value k such that:
 this.charAt(k) == ch
 
is true. If no such character occurs in this string, then -1 is returned.

Parameters: ch a character.

Returns: the index of the first occurrence of the character in the character sequence represented by this object, or -1 if the character does not occur.

indexOf

public int indexOf(int ch, int fromIndex)
Returns the index within this string of the first occurrence of the specified character, starting the search at the specified index.

If a character with value ch occurs in the character sequence represented by this String object at an index no smaller than fromIndex, then the index of the first such occurrence is returned--that is, the smallest value k such that:

 (this.charAt(k) == ch) && (k >= fromIndex)
 
is true. If no such character occurs in this string at or after position fromIndex, then -1 is returned.

There is no restriction on the value of fromIndex. If it is negative, it has the same effect as if it were zero: this entire string may be searched. If it is greater than the length of this string, it has the same effect as if it were equal to the length of this string: -1 is returned.

Parameters: ch a character. fromIndex the index to start the search from.

Returns: the index of the first occurrence of the character in the character sequence represented by this object that is greater than or equal to fromIndex, or -1 if the character does not occur.

indexOf

public int indexOf(String 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: java.lang.NullPointerException if str is null.

indexOf

public int indexOf(XMLString 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: java.lang.NullPointerException if str is null.

indexOf

public int indexOf(String str, int fromIndex)
Returns the index within this string of the first occurrence of the specified substring, starting at the specified index. The integer returned is the smallest value k such that:
 this.startsWith(str, k) && (k >= fromIndex)
 
is true.

There is no restriction on the value of fromIndex. If it is negative, it has the same effect as if it were zero: this entire string may be searched. If it is greater than the length of this string, it has the same effect as if it were equal to the length of this string: -1 is returned.

Parameters: str the substring to search for. fromIndex the index to start the search from.

Returns: If the string argument occurs as a substring within this object at a starting index no smaller than fromIndex, then the index of the first character of the first such substring is returned. If it does not occur as a substring starting at fromIndex or beyond, -1 is returned.

Throws: java.lang.NullPointerException if str is null

lastIndexOf

public int lastIndexOf(int ch)
Returns the index within this string of the last occurrence of the specified character. That is, the index returned is the largest value k such that:
 this.charAt(k) == ch
 
is true. The String is searched backwards starting at the last character.

Parameters: ch a character.

Returns: the index of the last occurrence of the character in the character sequence represented by this object, or -1 if the character does not occur.

lastIndexOf

public int lastIndexOf(int ch, int fromIndex)
Returns the index within this string of the last occurrence of the specified character, searching backward starting at the specified index. That is, the index returned is the largest value k such that:
 this.charAt(k) == ch) && (k <= fromIndex)
 
is true.

Parameters: ch a character. fromIndex the index to start the search from. There is no restriction on the value of fromIndex. If it is greater than or equal to the length of this string, it has the same effect as if it were equal to one less than the length of this string: this entire string may be searched. If it is negative, it has the same effect as if it were -1: -1 is returned.

Returns: the index of the last occurrence of the character in the character sequence represented by this object that is less than or equal to fromIndex, or -1 if the character does not occur before that point.

lastIndexOf

public int lastIndexOf(String str)
Returns the index within this string of the rightmost occurrence of the specified substring. The rightmost empty string "" is considered to occur at the index value this.length(). The returned index is the largest value k such that
 this.startsWith(str, k)
 
is true.

Parameters: str the substring to search for.

Returns: if the string argument occurs one or more times as a substring within this object, then the index of the first character of the last such substring is returned. If it does not occur as a substring, -1 is returned.

Throws: java.lang.NullPointerException if str is null.

lastIndexOf

public int lastIndexOf(String str, int fromIndex)
Returns the index within this string of the last occurrence of the specified substring.

Parameters: str the substring to search for. fromIndex the index to start the search from. There is no restriction on the value of fromIndex. If it is greater than the length of this string, it has the same effect as if it were equal to the length of this string: this entire string may be searched. If it is negative, it has the same effect as if it were -1: -1 is returned.

Returns: If the string argument occurs one or more times as a substring within this object at a starting index no greater than fromIndex, then the index of the first character of the last such substring is returned. If it does not occur as a substring starting at fromIndex or earlier, -1 is returned.

Throws: java.lang.NullPointerException if str is null.

length

public int length()
Returns the length of this string.

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

num

public double num()
Cast result object to a number.

Returns: 0.0 if this string is null, numeric value of this string or NaN

rtf

public int rtf(XPathContext support)
Cast result object to a result tree fragment.

Parameters: support Xpath context to use for the conversion

Returns: A document fragment with this string as a child node

startsWith

public boolean startsWith(String 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: java.lang.NullPointerException if prefix is null.

startsWith

public boolean startsWith(String 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 method.

Throws: java.lang.NullPointerException if prefix is null.

startsWith

public boolean startsWith(XMLString 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: java.lang.NullPointerException if prefix is null.

startsWith

public boolean startsWith(XMLString 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 method.

Throws: java.lang.NullPointerException if prefix is null.

str

public String str()
Cast result object to a string.

Returns: The string this wraps or the empty string if null

substring

public XMLString 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 XMLString 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.

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.

toLowerCase

public XMLString toLowerCase(Locale locale)
Converts all of the characters in this String to lower case using the rules of the given Locale.

Parameters: locale use the case transformation rules for this locale

Returns: the String, converted to lowercase.

See Also: java.lang.Character#toLowerCase(char) java.lang.String#toUpperCase(Locale)

toLowerCase

public XMLString toLowerCase()
Converts all of the characters in this String to lower case using the rules of the default locale, which is returned by Locale.getDefault.

Returns: the string, converted to lowercase.

See Also: java.lang.Character#toLowerCase(char) java.lang.String#toLowerCase(Locale)

toUpperCase

public XMLString toUpperCase(Locale locale)
Converts all of the characters in this String to upper case using the rules of the given locale.

Parameters: locale use the case transformation rules for this locale

Returns: the String, converted to uppercase.

See Also: java.lang.Character#toUpperCase(char) java.lang.String#toLowerCase(Locale)

toUpperCase

public XMLString toUpperCase()
Converts all of the characters in this String to upper case using the rules of the default locale, which is returned by Locale.getDefault.

If no character in this string has a different uppercase version, based on calling the toUpperCase method defined by Character, then the original string is returned.

Otherwise, this method creates a new String object representing a character sequence identical in length to the character sequence represented by this String object and with every character equal to the result of applying the method Character.toUpperCase to the corresponding character of this String object.

Examples:

 "Fahrvergnügen".toUpperCase() returns "FAHRVERGNÜGEN"
 "Visit Ljubinje!".toUpperCase() returns "VISIT LJUBINJE!"
 

Returns: the string, converted to uppercase.

See Also: java.lang.Character#toUpperCase(char) java.lang.String#toUpperCase(Locale)

trim

public XMLString trim()
Removes white space from both ends of this string.

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

xstr

public XMLString xstr()
Cast result object to a string.

Returns: The string this wraps or the empty string if null

Copyright B) 2006 Apache XML Project. All Rights Reserved.