net.sf.saxon.value
Class StringValue

java.lang.Object
  net.sf.saxon.value.Value
      net.sf.saxon.value.AtomicValue
          net.sf.saxon.value.StringValue

All Implemented Interfaces:

Serializable, Expression, Item

Direct Known Subclasses:

RestrictedStringValue, UntypedAtomicValue

public class StringValue
extends AtomicValue

A string value

See Also:

Serialized Form

Nested Class Summary

class

StringValue.CharacterIterator CharacterIterator is used to iterate over the characters in a string, returning them as integers representing the Unicode code-point.

Field Summary

static StringValue	EMPTY_STRING
protected int	length
protected CharSequence	value

Constructor Summary

protected	StringValue() Protected constructor for use by subtypes
	StringValue(CharSequence value) Constructor.

Method Summary

int	conversionPreference(Class required) Get conversion preference for this value to a Java class.
AtomicValue	convert(int requiredType) Convert to target data type
Object	convertToJava(Class target) Convert to Java object (for passing to external functions)
void	display(int level, NamePool pool) Diagnostic print of expression structure
boolean	effectiveBooleanValue(XPathContext context) Get the effective boolean value of the value
boolean	equals(Object other) Determine if two StringValues are equal
static int[]	expand(CharSequence s) Expand a string containing surrogate pairs into an array of 32-bit characters
ItemType	getItemType() Return the type of the expression
int	getLength() Get the length of this string, as defined in XPath.
static int	getLength(CharSequence s) Get the length of a string, as defined in XPath.
String	getStringValue() Get the string value as a String
int	hashCode()
SequenceIterator	iterateCharacters() Iterate over a string, returning a sequence of integers representing the Unicode code-point values
String	toString()

Methods inherited from class net.sf.saxon.value.AtomicValue

convert, convert, evaluateAsString, evaluateItem, getCardinality, getComponent, getPrimitiveValue, getTypedValue, iterate

Methods inherited from class net.sf.saxon.value.Value

analyze, asItem, asValue, collapseWhitespace, getDependencies, getSpecialProperties, getSubExpressions, inverse, normalizeWhitespace, promote, simplify, stringToInteger, stringToNumber, trimWhitespace

Methods inherited from class java.lang.Object

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

Field Detail

EMPTY_STRING

public static final StringValue EMPTY_STRING

value

protected CharSequence value

length

protected int length

Constructor Detail

StringValue

protected StringValue()

Protected constructor for use by subtypes

StringValue

public StringValue(CharSequence value)

Constructor. Note that although a StringValue may wrap any kind of CharSequence (usually a String, but it can also be, for example, a StringBuffer), the caller is responsible for ensuring that the value is immutable.

Parameters:

value - the String value. Null is taken as equivalent to "".

Method Detail

getStringValue

public final String getStringValue()

Get the string value as a String

Returns:

the string value of the item

convert

public AtomicValue convert(int requiredType)
                    throws XPathException

Convert to target data type

Specified by:

convert in class AtomicValue

Parameters:

requiredType - an integer identifying the required atomic type

Returns:

an AtomicValue, a value of the required type

Throws:

XPathException - if the conversion is not possible

getItemType

public ItemType getItemType()

Return the type of the expression

Returns:

Type.STRING (always)

getLength

public int getLength()

Get the length of this string, as defined in XPath. This is not the same as the Java length, as a Unicode surrogate pair counts as a single character

getLength

public static int getLength(CharSequence s)

Get the length of a string, as defined in XPath. This is not the same as the Java length, as a Unicode surrogate pair counts as a single character.

Parameters:

s - The string whose length is required

iterateCharacters

public SequenceIterator iterateCharacters()

Iterate over a string, returning a sequence of integers representing the Unicode code-point values

expand

public static int[] expand(CharSequence s)

Expand a string containing surrogate pairs into an array of 32-bit characters

equals

public boolean equals(Object other)

Determine if two StringValues are equal

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

effectiveBooleanValue

public boolean effectiveBooleanValue(XPathContext context)

Description copied from class: AtomicValue

Get the effective boolean value of the value

Specified by:

effectiveBooleanValue in interface Expression

Overrides:

effectiveBooleanValue in class AtomicValue

Parameters:

context - the evaluation context (not used in this implementation)

Returns:

true, unless the value is boolean false, numeric zero, or zero-length string

conversionPreference

public int conversionPreference(Class required)

Get conversion preference for this value to a Java class. A low result indicates higher preference.

Overrides:

conversionPreference in class AtomicValue

convertToJava

public Object convertToJava(Class target)
                     throws XPathException

Convert to Java object (for passing to external functions)

Overrides:

convertToJava in class AtomicValue

Parameters:

target - The class required by the external function

Returns:

an object of the target class

Throws:

XPathException

display

public void display(int level,
                    NamePool pool)

Diagnostic print of expression structure

Parameters:

level - indentation level for this expression

toString

public String toString()

Overrides:

toString in class Object