org.apache.xpath.objects

Class XStringForFSB

java.lang.Object

org.apache.xpath.Expression

org.apache.xpath.objects.XObject

org.apache.xpath.objects.XString

org.apache.xpath.objects.XStringForFSB

All Implemented Interfaces:

Serializable, Cloneable, SourceLocator, XMLString, ExpressionNode, XPathVisitable

public class XStringForFSB
extends XString

This class will wrap a FastStringBuffer and allow for

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
protected int	m_hash cached hash code
protected String	m_strCache If the str() function is called, the string will be cached here.

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

EMPTYSTRING

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, m_obj

Constructor Summary

Constructors

Constructor and Description
XStringForFSB(FastStringBuffer val, int start, int length) Construct a XNodeSet object.

Method Summary

Modifier and Type	Method and Description
void	appendToFsb(FastStringBuffer fsb) Cast result object to a string.
char	charAt(int index) Returns the character at the specified index.
int	compareTo(XMLString xstr) Compares two strings lexicographically.
int	compareToIgnoreCase(XMLString xstr) Compares two strings lexicographically, ignoring case considerations.
XMLString	concat(String str) Concatenates the specified string to the end of this string.
void	dispatchAsComment(LexicalHandler lh) Directly call the comment method on the passed LexicalHandler for the string-value.
void	dispatchCharactersEvents(ContentHandler ch) Directly call the characters method on the passed ContentHandler for the string-value.
boolean	equals(Object obj2) Compares this string to the specified object.
boolean	equals(String anotherString) Tell if two objects are functionally equal.
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.
FastStringBuffer	fsb() Cast result object to a string.
void	getChars(int srcBegin, int srcEnd, char[] dst, int dstBegin) Copies characters from this string into the destination character array.
int	hashCode() Returns a hashcode for this string.
boolean	hasString() Tell if this object contains a java String object.
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	length() Returns the length of this string.
Object	object() Since this object is incomplete without the length and the offset, we have to convert to a string when this function is called.
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	trim() Removes white space from both ends of this string.

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

bool, callVisitors, endsWith, getType, getTypeString, indexOf, indexOf, indexOf, lastIndexOf, lastIndexOf, lastIndexOf, lastIndexOf, num, rtf, startsWith, startsWith, toLowerCase, toLowerCase, toUpperCase, toUpperCase, xstr

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

allowDetachToRelease, boolWithSideEffects, castToType, create, create, deepEquals, destruct, detach, error, error, execute, fixupVariables, getFresh, greaterThan, greaterThanOrEqual, iter, lessThan, lessThanOrEqual, mutableNodeset, nodelist, nodeset, notEquals, numWithSideEffects, reset, rtf, rtree, rtree, setObject, toString

Methods inherited from class org.apache.xpath.Expression

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

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.xml.utils.XMLString

toString

Field Detail

m_strCache

protected String m_strCache

If the str() function is called, the string will be cached here.

m_hash

protected int m_hash

cached hash code

Constructor Detail

XStringForFSB

public XStringForFSB(FastStringBuffer val,
                     int start,
                     int length)

Construct a XNodeSet object.

Parameters:

val - FastStringBuffer object this will wrap, must be non-null.

start - The start position in the array.

length - The number of characters to read from the array.

Method Detail

fsb

public FastStringBuffer fsb()

Cast result object to a string.

Returns:

The string this wraps or the empty string if null

appendToFsb

public void appendToFsb(FastStringBuffer fsb)

Cast result object to a string.

Overrides:

appendToFsb in class XObject

hasString

public boolean hasString()

Tell if this object contains a java String object.

Specified by:

hasString in interface XMLString

Overrides:

hasString in class XString

Returns:

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

object

public Object object()

Since this object is incomplete without the length and the offset, we have to convert to a string when this function is called.

Overrides:

object in class XObject

Returns:

The java String representation of this object.

str

public String str()

Cast result object to a string.

Overrides:

str in class XString

Returns:

The string this wraps or the empty string if null

dispatchCharactersEvents

public void dispatchCharactersEvents(ContentHandler ch)
                              throws 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 class XString

Parameters:

ch - A non-null reference to a ContentHandler.

Throws:

SAXException

dispatchAsComment

public void dispatchAsComment(LexicalHandler lh)
                       throws SAXException

Directly call the comment method on the passed LexicalHandler for the string-value.

Specified by:

dispatchAsComment in interface XMLString

Overrides:

dispatchAsComment in class XString

Parameters:

lh - A non-null reference to a LexicalHandler.

Throws:

SAXException

length

public int length()

Returns the length of this string.

Specified by:

length in interface XMLString

Overrides:

length in class XString

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.

Specified by:

charAt in interface XMLString

Overrides:

charAt in class XString

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.

Specified by:

getChars in interface XMLString

Overrides:

getChars in class XString

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(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

Overrides:

equals in class XString

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(XObject obj2)

Tell if two objects are functionally equal.

Overrides:

equals in class XString

Parameters:

obj2 - Object to compare this to

Returns:

true if the two objects are equal

Throws:

TransformerException

equals

public boolean equals(String anotherString)

Tell if two objects are functionally equal.

Specified by:

equals in interface XMLString

Overrides:

equals in class XString

Parameters:

anotherString - Object to compare this to

Returns:

true if the two objects are equal

Throws:

TransformerException

See Also:

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

Specified by:

equals in interface XMLString

Overrides:

equals in class XString

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)

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

Overrides:

equalsIgnoreCase in class XString

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(Object), Character.toLowerCase(char), Character.toUpperCase(char)

compareTo

public int compareTo(XMLString xstr)

Compares two strings lexicographically.

Specified by:

compareTo in interface XMLString

Overrides:

compareTo in class XString

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:

NullPointerException - if anotherString is null.

compareToIgnoreCase

public int compareToIgnoreCase(XMLString xstr)

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

Overrides:

compareToIgnoreCase in class XString

Parameters:

xstr - 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:

Collator.compare(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.)

Specified by:

hashCode in interface XMLString

Overrides:

hashCode in class XString

Returns:

a hash code value for this object.

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

Overrides:

startsWith in class XString

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(XMLString prefix)

Tests if this string starts with the specified prefix.

Specified by:

startsWith in interface XMLString

Overrides:

startsWith in class XString

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.

Since:

JDK1. 0

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

Overrides:

indexOf in class XString

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

Overrides:

indexOf in class XString

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.

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

Overrides:

substring in class XString

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.

Specified by:

substring in interface XMLString

Overrides:

substring in class XString

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.

concat

public XMLString concat(String str)

Concatenates the specified string to the end of this string.

Specified by:

concat in interface XMLString

Overrides:

concat in class XString

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:

NullPointerException - if str is null.

trim

public XMLString trim()

Removes white space from both ends of this string.

Specified by:

trim in interface XMLString

Overrides:

trim in class XString

Returns:

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

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

Overrides:

fixWhiteSpace in class XString

Parameters:

trimHead - Trim leading whitespace?

trimTail - Trim trailing whitespace?

doublePunctuationSpaces - Use double spaces for punctuation?

Returns:

The trimmed string.

toDouble

public double toDouble()

Convert a string to a double -- Allowed input is in fixed notation ddd.fff. %OPT% CHECK PERFORMANCE against generating a Java String and converting it to double. The advantage of running in native machine code -- perhaps even microcode, on some systems -- may more than make up for the cost of allocating and discarding the additional object. We need to benchmark this. %OPT% More importantly, we need to decide whether we _care_ about the performance of this operation. Does XString.toDouble constitute any measurable percentage of our typical runtime? I suspect not!

Specified by:

toDouble in interface XMLString

Overrides:

toDouble in class XString

Returns:

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