Package 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
,ValueRepresentation
- Direct Known Subclasses:
AnyURIValue
,RestrictedStringValue
,UntypedAtomicValue
An atomic value of type xs:string
- See Also:
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Nested Class Summary
Nested ClassesModifier and TypeClassDescriptionfinal class
CharacterIterator is used to iterate over the characters in a string, returning them as integers representing the Unicode code-point. -
Field Summary
FieldsModifier and TypeFieldDescriptionstatic final StringValue
static final StringValue
protected int
static final StringValue
static final StringValue
protected CharSequence
Fields inherited from class net.sf.saxon.value.Value
EMPTY_CLASS_ARRAY
Fields inherited from interface net.sf.saxon.expr.Expression
EVALUATE_METHOD, ITERATE_METHOD, PROCESS_METHOD
Fields inherited from interface net.sf.saxon.om.ValueRepresentation
EMPTY_VALUE_ARRAY
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Constructor Summary
ConstructorsModifierConstructorDescriptionprotected
Protected constructor for use by subtypesStringValue
(CharSequence value) Constructor. -
Method Summary
Modifier and TypeMethodDescriptionboolean
codepointEquals
(StringValue other) Test whether this StringValue is equal to another under the rules of the codepoint collationboolean
Determine whether the string contains surrogate pairsstatic CharSequence
contract
(int[] codes, int used) Contract an array of integers containing Unicode codepoints into a Java stringconvertPrimitive
(BuiltInAtomicType requiredType, boolean validate, XPathContext context) Convert a value to another primitive data type, with control over how validation is handled.static AtomicValue
convertStringToAtomicType
(CharSequence value, AtomicType targetType, NameChecker checker) Convert the value to a given type.static AtomicValue
convertStringToBuiltInType
(CharSequence value, BuiltInAtomicType requiredType, NameChecker checker) Convert a string value to another built-in data type, with control over how validation is handled.convertToJava
(Class target, XPathContext context) Convert to Java object (for passing to external functions)boolean
effectiveBooleanValue
(XPathContext context) Get the effective boolean value of a stringboolean
Determine if two StringValues are equal, according to XML Schema rules.int[]
expand()
Expand a string containing surrogate pairs into an array of 32-bit charactersstatic int[]
Expand a string containing surrogate pairs into an array of 32-bit charactersReturn the type of the expressionint
Get the length of this string, as defined in XPath.static int
Get the length of a string, as defined in XPath.final String
Get the string value as a Stringfinal CharSequence
Get the value of the item as a CharSequence.int
hashCode()
Return a hash code to support the equals() functionboolean
Determine whether the string is a zero-length string.Iterate over a string, returning a sequence of integers representing the Unicode code-point valuesstatic StringValue
makeStringValue
(CharSequence value) Factory method.toString()
Get string value.Methods inherited from class net.sf.saxon.value.AtomicValue
checkPermittedContents, convert, convert, display, evaluateAsString, evaluateItem, getCardinality, getComponent, getImplementationMethod, getLength, getPrimitiveValue, getTypedValue, hasBuiltInType, iterate, process
Methods inherited from class net.sf.saxon.value.Value
asItem, asIterator, asValue, convert, convertJavaObjectToXPath, getDependencies, getIterator, getParentExpression, getSpecialProperties, itemAt, iterateSubExpressions, makeQNameValue, optimize, promote, reduce, simplify, stringToNumber, typeCheck
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Field Details
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EMPTY_STRING
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SINGLE_SPACE
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TRUE
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FALSE
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value
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length
protected int length
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Constructor Details
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StringValue
protected StringValue()Protected constructor for use by subtypes -
StringValue
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 "".
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Method Details
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makeStringValue
Factory method. Unlike the constructor, this avoids creating a new StringValue in the case of a zero-length string (and potentially other strings, in future)- Parameters:
value
- the String value. Null is taken as equivalent to "".- Returns:
- the corresponding StringValue
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getStringValue
Get the string value as a String- Specified by:
getStringValue
in interfaceItem
- Specified by:
getStringValue
in interfaceValueRepresentation
- Specified by:
getStringValue
in classAtomicValue
- Returns:
- the string value of the item
- See Also:
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getStringValueCS
Get the value of the item as a CharSequence. This is in some cases more efficient than the version of the method that returns a String.- Specified by:
getStringValueCS
in interfaceItem
- Specified by:
getStringValueCS
in interfaceValueRepresentation
- Overrides:
getStringValueCS
in classAtomicValue
- Returns:
- the string value of the item
- See Also:
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convertPrimitive
public AtomicValue convertPrimitive(BuiltInAtomicType requiredType, boolean validate, XPathContext context) Convert a value to another primitive data type, with control over how validation is handled.- Specified by:
convertPrimitive
in classAtomicValue
- Parameters:
requiredType
- type code of the required atomic typevalidate
- true if validation is required. If set to false, the caller guarantees that the value is valid for the target data type, and that further validation is therefore not required. Note that a validation failure may be reported even if validation was not requested.context
-- Returns:
- the result of the conversion, if successful. If unsuccessful, the value returned will be a ValidationErrorValue. The caller must check for this condition. No exception is thrown, instead the exception will be encapsulated within the ErrorValue.
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convertStringToBuiltInType
public static AtomicValue convertStringToBuiltInType(CharSequence value, BuiltInAtomicType requiredType, NameChecker checker) Convert a string value to another built-in data type, with control over how validation is handled.- Parameters:
value
- the value to be convertedrequiredType
- the required atomic typechecker
- if validation is required, a NameChecker. If set to null, the caller guarantees that the value is valid for the target data type, and that further validation is therefore not required. Note that a validation failure may be reported even if validation was not requested.- Returns:
- the result of the conversion, if successful. If unsuccessful, the value returned
will be a
ValidationErrorValue
. The caller must check for this condition. No exception is thrown, instead the exception will be encapsulated within the ValidationErrorValue.
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convertStringToAtomicType
public static AtomicValue convertStringToAtomicType(CharSequence value, AtomicType targetType, NameChecker checker) Convert the value to a given type. The result of the conversion will be an atomic value of the required type. This method works where the target type is a built-in atomic type and also where it is a user-defined atomic type.- Parameters:
targetType
- the type to which the value is to be convertedchecker
- a NameChecker if validation is required, null if the caller already knows that the value is valid- Returns:
- the value after conversion if successful; or a
ValidationErrorValue
if conversion failed. The caller must check for this condition. Validation may fail even if validation was not requested.
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getItemType
Return the type of the expression- Specified by:
getItemType
in interfaceExpression
- Overrides:
getItemType
in classValue
- Parameters:
th
-- Returns:
- Type.STRING (always)
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getStringLength
public int getStringLength()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 -
getStringLength
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
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isZeroLength
public boolean isZeroLength()Determine whether the string is a zero-length string. This may be more efficient than testing whether the length is equal to zero -
containsSurrogatePairs
public boolean containsSurrogatePairs()Determine whether the string contains surrogate pairs- Returns:
- true if the string contains any non-BMP characters
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iterateCharacters
Iterate over a string, returning a sequence of integers representing the Unicode code-point values -
expand
public int[] expand()Expand a string containing surrogate pairs into an array of 32-bit characters -
expand
Expand a string containing surrogate pairs into an array of 32-bit characters -
contract
Contract an array of integers containing Unicode codepoints into a Java string -
equals
Determine if two StringValues are equal, according to XML Schema rules. (This method is not used for XPath comparisons, which are always under the control of a collation.)- Overrides:
equals
in classValue
- Throws:
ClassCastException
- if the values are not comparable
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hashCode
public int hashCode()Description copied from class:Value
Return a hash code to support the equals() function -
codepointEquals
Test whether this StringValue is equal to another under the rules of the codepoint collation -
effectiveBooleanValue
Get the effective boolean value of a string- Specified by:
effectiveBooleanValue
in interfaceExpression
- Overrides:
effectiveBooleanValue
in classAtomicValue
- Parameters:
context
- not used- Returns:
- true if the string has length greater than zero
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convertToJava
Convert to Java object (for passing to external functions)- Overrides:
convertToJava
in classValue
- Throws:
XPathException
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toString
Description copied from class:AtomicValue
Get string value. In general toString() for an atomic value displays the value as it would be written in XPath: that is, as a literal if available, or as a call on a constructor function otherwise.- Overrides:
toString
in classAtomicValue
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