org.apache.xpath.objects

Class XString

Implemented Interfaces:
Cloneable, Serializable, ExpressionNode, SourceLocator, XMLString, XPathVisitable
Known Direct Subclasses:
XStringForChars, XStringForFSB

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.
See Also:
Serialized Form

Field Summary

static XString
EMPTYSTRING
Empty string XString object

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

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

Constructor Summary

XString(String val)
Construct a XNodeSet object.

Method Summary

boolean
bool()
Cast result object to a boolean.
void
callVisitors(ExpressionOwner owner, XPathVisitor visitor)
char
charAt(int index)
Returns the character at the specified index.
int
compareTo(XMLString xstr)
Compares two strings lexicographically.
int
compareToIgnoreCase(XMLString str)
Compares two strings lexicographically, ignoring case considerations.
XMLString
concat(String str)
Concatenates the specified string to the end of this string.
void
dispatchAsComment(org.xml.sax.ext.LexicalHandler lh)
Directly call the comment method on the passed LexicalHandler for the string-value.
void
dispatchCharactersEvents(org.xml.sax.ContentHandler ch)
Directly call the characters method on the passed ContentHandler for the string-value.
boolean
endsWith(String suffix)
Tests if this string ends with the specified suffix.
boolean
equals(Object obj2)
Compares this string to the specified object.
boolean
equals(XMLString obj2)
Compares this string to the specified object.
boolean
equals(XObject obj2)
Tell if two objects are functionally equal.
boolean
equalsIgnoreCase(String anotherString)
Compares this String to another String, ignoring case considerations.
XMLString
fixWhiteSpace(boolean trimHead, boolean trimTail, boolean doublePunctuationSpaces)
Conditionally trim all leading and trailing whitespace in the specified String.
void
getChars(int srcBegin, int srcEnd, dst[] , int dstBegin)
Copies characters from this string into the destination character array.
int
getType()
Tell that this is a CLASS_STRING.
String
getTypeString()
Given a request type, return the equivalent string.
boolean
hasString()
Tell if this object contains a java String object.
int
hashCode()
Returns a hashcode for this string.
int
indexOf(String str)
Returns the index within this string of the first occurrence of the specified substring.
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.
int
indexOf(int ch)
Returns the index within this string of the first occurrence of the specified character.
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.
int
indexOf(XMLString str)
Returns the index within this string of the first occurrence of the specified substring.
int
lastIndexOf(String str)
Returns the index within this string of the rightmost occurrence of the specified substring.
int
lastIndexOf(String str, int fromIndex)
Returns the index within this string of the last occurrence of the specified substring.
int
lastIndexOf(int ch)
Returns the index within this string of the last occurrence of the specified character.
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.
int
length()
Returns the length of this string.
double
num()
Cast result object to a number.
int
rtf(XPathContext support)
Cast result object to a result tree fragment.
boolean
startsWith(String prefix)
Tests if this string starts with the specified prefix.
boolean
startsWith(String prefix, int toffset)
Tests if this string starts with the specified prefix beginning a specified index.
boolean
startsWith(XMLString prefix)
Tests if this string starts with the specified prefix.
boolean
startsWith(XMLString prefix, int toffset)
Tests if this string starts with the specified prefix beginning a specified index.
String
str()
Cast result object to a string.
XMLString
substring(int beginIndex)
Returns a new string that is a substring of this string.
XMLString
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.
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.
XMLString
toLowerCase(Locale locale)
Converts all of the characters in this String to lower case using the rules of the given Locale.
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.
XMLString
toUpperCase(Locale locale)
Converts all of the characters in this String to upper case using the rules of the given locale.
XMLString
trim()
Removes white space from both ends of this string.
XMLString
xstr()
Cast result object to a string.

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

allowDetachToRelease, appendToFsb, bool, boolWithSideEffects, callVisitors, castToType, create, create, deepEquals, destruct, detach, dispatchCharactersEvents, equals, execute, fixupVariables, getFresh, getType, getTypeString, greaterThan, greaterThanOrEqual, iter, lessThan, lessThanOrEqual, mutableNodeset, nodelist, nodeset, notEquals, num, numWithSideEffects, object, reset, rtf, rtf, rtree, rtree, str, toString, xstr

Methods inherited from class org.apache.xpath.Expression

asIterator, asIteratorRaw, asNode, assertion, bool, canTraverseOutsideSubtree, deepEquals, error, execute, execute, execute, execute, executeCharsToContentHandler, exprAddChild, exprGetChild, exprGetNumChildren, exprGetParent, exprSetParent, fixupVariables, getColumnNumber, getExpressionOwner, getLineNumber, getPublicId, getSystemId, isNodesetExpr, isStableNumber, num, warn, xstr

Field Details

EMPTYSTRING

public static XString EMPTYSTRING
Empty string XString object

Constructor Details

XString

public XString(String val)
Construct a XNodeSet object.
Parameters:
val - String object this will wrap.

Method Details

bool

public boolean bool()
Cast result object to a boolean.
Overrides:
bool in interface XObject
Returns:
True if the length of this string object is greater than 0.

callVisitors

public void callVisitors(ExpressionOwner owner,
                         XPathVisitor visitor)
Specified by:
callVisitors in interface XPathVisitable
Overrides:
callVisitors in interface XObject
See Also:
XPathVisitable.callVisitors(ExpressionOwner, XPathVisitor)

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.
Specified by:
charAt in interface XMLString
Parameters:
index - the index of the character.
Returns:
the character at the specified index of this string. The first character is at index 0.

compareTo

public int compareTo(XMLString xstr)
Compares two strings lexicographically.
Specified by:
compareTo in interface XMLString
Parameters:
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.

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.

Specified by:
compareToIgnoreCase in interface XMLString
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

concat

public XMLString concat(String str)
Concatenates the specified string to the end of this string.
Specified by:
concat in interface XMLString
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.

dispatchAsComment

public void dispatchAsComment(org.xml.sax.ext.LexicalHandler lh)
            throws org.xml.sax.SAXException
Directly call the comment method on the passed LexicalHandler for the string-value.
Specified by:
dispatchAsComment in interface XMLString
Parameters:
lh - A non-null reference to a LexicalHandler.

dispatchCharactersEvents

public void dispatchCharactersEvents(org.xml.sax.ContentHandler ch)
            throws org.xml.sax.SAXException
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.
Specified by:
dispatchCharactersEvents in interface XMLString
Overrides:
dispatchCharactersEvents in interface XObject
Parameters:
ch - A non-null reference to a ContentHandler.

endsWith

public boolean endsWith(String suffix)
Tests if this string ends with the specified suffix.
Specified by:
endsWith in interface XMLString
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(Object) method.

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.
Specified by:
equals in interface XMLString
Parameters:
Returns:
true if the String are equal; false otherwise.

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.
Specified by:
equals in interface XMLString
Parameters:
obj2 - the object to compare this String against.
Returns:
true if the String are equal; false otherwise.

equals

public boolean equals(XObject obj2)
Tell if two objects are functionally equal.
Overrides:
equals in interface XObject
Parameters:
obj2 - Object to compare this to
Returns:
true if the two objects are equal

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.
Specified by:
equalsIgnoreCase in interface XMLString
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.

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.
Specified by:
fixWhiteSpace in interface XMLString
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,
                     dst[] ,
                     int dstBegin)
Copies characters from this string into the destination character array.
Specified by:
getChars in interface XMLString
Parameters:
srcBegin - index of the first character in the string to copy.
srcEnd - index after the last character in the string to copy.
dstBegin - the start offset in the destination array.

getType

public int getType()
Tell that this is a CLASS_STRING.
Overrides:
getType in interface XObject
Returns:
type CLASS_STRING

getTypeString

public String getTypeString()
Given a request type, return the equivalent string. For diagnostic purposes.
Overrides:
getTypeString in interface XObject
Returns:
type string "#STRING"

hasString

public boolean hasString()
Tell if this object contains a java String object.
Specified by:
hasString in interface XMLString
Returns:
true if this XMLString can return a string without creating one.

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.)
Specified by:
hashCode in interface XMLString
Returns:
a hash code value for this object.

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.
Specified by:
indexOf in interface XMLString
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.

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.

Specified by:
indexOf in interface XMLString
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.

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.
Specified by:
indexOf in interface XMLString
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.

Specified by:
indexOf in interface XMLString
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(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.
Specified by:
indexOf in interface XMLString
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.

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.
Specified by:
lastIndexOf in interface XMLString
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.

lastIndexOf

public int lastIndexOf(String str,
                       int fromIndex)
Returns the index within this string of the last occurrence of the specified substring.
Specified by:
lastIndexOf in interface XMLString
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.

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.
Specified by:
lastIndexOf in interface XMLString
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.
Specified by:
lastIndexOf in interface XMLString
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.

length

public int length()
Returns the length of this string.
Specified by:
length in interface XMLString
Returns:
the length of the sequence of characters represented by this object.

num

public double num()
Cast result object to a number.
Overrides:
num in interface XObject
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.
Overrides:
rtf in interface XObject
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)
Tests if this string starts with the specified prefix.
Specified by:
startsWith in interface XMLString
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.

startsWith

public boolean startsWith(String prefix,
                          int toffset)
Tests if this string starts with the specified prefix beginning a specified index.
Specified by:
startsWith in interface XMLString
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)

startsWith

public boolean startsWith(XMLString prefix)
Tests if this string starts with the specified prefix.
Specified by:
startsWith in interface XMLString
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.

startsWith

public boolean startsWith(XMLString prefix,
                          int toffset)
Tests if this string starts with the specified prefix beginning a specified index.
Specified by:
startsWith in interface XMLString
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)

str

public String str()
Cast result object to a string.
Overrides:
str in interface XObject
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)
 
Specified by:
substring in interface XMLString
Parameters:
beginIndex - the beginning index, inclusive.
Returns:
the specified substring.

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.
Specified by:
substring in interface XMLString
Parameters:
beginIndex - the beginning index, inclusive.
endIndex - the ending index, exclusive.
Returns:
the specified substring.

toDouble

public double toDouble()
Convert a string to a double -- Allowed input is in fixed notation ddd.fff.
Specified by:
toDouble in interface XMLString
Returns:
A double value representation of the string, or return Double.NaN if the string can not be converted.

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.

Specified by:
toLowerCase in interface XMLString
Returns:
the string, converted to lowercase.

toLowerCase

public XMLString toLowerCase(Locale locale)
Converts all of the characters in this String to lower case using the rules of the given Locale.
Specified by:
toLowerCase in interface XMLString
Parameters:
locale - use the case transformation rules for this locale
Returns:
the String, converted to lowercase.

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:

 "Fahrvergn?gen".toUpperCase() returns "FAHRVERGN?GEN"
 "Visit Ljubinje!".toUpperCase() returns "VISIT LJUBINJE!"
 
Specified by:
toUpperCase in interface XMLString
Returns:
the string, converted to uppercase.

toUpperCase

public XMLString toUpperCase(Locale locale)
Converts all of the characters in this String to upper case using the rules of the given locale.
Specified by:
toUpperCase in interface XMLString
Parameters:
locale - use the case transformation rules for this locale
Returns:
the String, converted to uppercase.

trim

public XMLString trim()
Removes white space from both ends of this string.
Specified by:
trim in interface XMLString
Returns:
this string, with white space removed from the front and end.

xstr

public XMLString xstr()
Cast result object to a string.
Overrides:
xstr in interface XObject
Returns:
The string this wraps or the empty string if null

Copyright B) 2004 Apache XML Project. All Rights Reserved.