OpenJDK 27 · javax.xml.xpath.XPathExpression · APIdia, the JavaDoc alternative

Evaluation of XPath Expressions
Factor	Behavior
context	The type of the context is implementation-dependent. If the value is null, the operation must have no dependency on the context, otherwise an XPathExpressionException will be thrown. For the purposes of evaluating XPath expressions, a DocumentFragment is treated like a Document node.
variables	If the expression contains a variable reference, its value will be found through the `XPathVariableResolver`. An `XPathExpressionException` is raised if the variable resolver is undefined or the resolver returns `null` for the variable. The value of a variable must be immutable through the course of any single evaluation.
functions	If the expression contains a function reference, the function will be found through the `XPathFunctionResolver`. An `XPathExpressionException` is raised if the function resolver is undefined or the function resolver returns `null` for the function.
QNames	QNames in the expression are resolved against the XPath namespace context.
result	This result of evaluating an expression is converted to an instance of the desired return type. Valid return types are defined in `XPathConstants`. Conversion to the return type follows XPath conversion rules.

Method Summary

Modifier and Type	Method and Description
public Object	Returns: The `Object` that is the result of evaluating the expression and converting the result to `returnType`. evaluate(Object The context the XPath expression will be evaluated in. item, QName The result type expected to be returned by the XPath expression. returnType) Evaluate the compiled XPath expression in the specified context and return the result as the specified type.
public String	Returns: The result of evaluating an XPath expression as a `String`. evaluate(Object The context the XPath expression will be evaluated in. item) Evaluate the compiled XPath expression in the specified context and return the result as a `String`.
public Object	Returns: The `Object` that is the result of evaluating the expression and converting the result to `returnType`. evaluate(InputSource The `InputSource` of the document to evaluate over. source, QName The desired return type. returnType) Evaluate the compiled XPath expression in the context of the specified `InputSource` and return the result as the specified type.
public String	Returns: The `String` that is the result of evaluating the expression and converting the result to a `String`. evaluate(InputSource The `InputSource` of the document to evaluate over. source) Evaluate the compiled XPath expression in the context of the specified `InputSource` and return the result as a `String`.
public default < The class type that will be returned by the XPath expression. T> T	Returns: The result of evaluating the expression. evaluateExpression(Object The context the XPath expression will be evaluated in. item, Class<T> The class type expected to be returned by the XPath expression, must be one of the types described in section 3.2 Class types in the package summary. type) Evaluate the compiled XPath expression in the specified context, and return the result with the type specified through the `class type`.
public default XPathEvaluationResult<?>	Returns: The result of evaluating the expression. evaluateExpression(Object The context the XPath expression will be evaluated in. item) Evaluate the compiled XPath expression in the specified context.
public default < The class type that will be returned by the XPath expression. T> T	Returns: The result of evaluating the expression. evaluateExpression(InputSource The `InputSource` of the document to evaluate over. source, Class<T> The class type expected to be returned by the XPath expression, must be one of the types described in section 3.2 Class types in the package summary. type) Evaluate the compiled XPath expression in the specified context, and return the result with the type specified through the `class type` This method builds a data model for the `InputSource` and calls `evaluateExpression(Object item, Class type)` on the resulting document object.
public default XPathEvaluationResult<?>	Returns: The result of evaluating the expression. evaluateExpression(InputSource The `InputSource` of the document to evaluate over. source) Evaluate the compiled XPath expression in the specified context.

Method Detail

evaluate back to summary

evaluate	back to summary
public Object evaluate(Object item, QName returnType) throws XPathExpressionException Evaluate the compiled XPath expression in the specified context and return the result as the specified type. See Evaluation of XPath Expressions for context item evaluation, variable, function and QName resolution and return type conversion. The parameter `item` represents the context the XPath expression will be operated on. The type of the context is implementation-dependent. If the value is `null`, the operation must have no dependency on the context, otherwise an XPathExpressionException will be thrown. Implementation Note The type of the context is usually `org.w3c.dom.Node`. Parameters item:Object The context the XPath expression will be evaluated in. returnType:QName The result type expected to be returned by the XPath expression. Returns:Object The `Object` that is the result of evaluating the expression and converting the result to `returnType`. Exceptions XPathExpressionException: If the expression cannot be evaluated. IllegalArgumentException: If `returnType` is not one of the types defined in `XPathConstants`. NullPointerException: If `returnType` is `null`.

public Object evaluate(Object item, QName returnType) throws XPathExpressionException

Evaluate the compiled XPath expression in the specified context and return the result as the specified type.

See Evaluation of XPath Expressions for context item evaluation, variable, function and QName resolution and return type conversion.

The parameter item represents the context the XPath expression will be operated on. The type of the context is implementation-dependent. If the value is null, the operation must have no dependency on the context, otherwise an XPathExpressionException will be thrown.

Implementation Note

The type of the context is usually org.w3c.dom.Node.

Parameters

item:Object: The context the XPath expression will be evaluated in.
returnType:QName: The result type expected to be returned by the XPath expression.

Returns:Object

The Object that is the result of evaluating the expression and converting the result to returnType.

Exceptions

XPathExpressionException:: If the expression cannot be evaluated.
IllegalArgumentException:: If returnType is not one of the types defined in XPathConstants.
NullPointerException:: If returnType is null.

evaluate back to summary

evaluate	back to summary
public String evaluate(Object item) throws XPathExpressionException Evaluate the compiled XPath expression in the specified context and return the result as a `String`. This method calls `evaluate(Object item, QName returnType)` with a `returnType` of `XPathConstants#STRING`. See Evaluation of XPath Expressions for context item evaluation, variable, function and QName resolution and return type conversion. The parameter `item` represents the context the XPath expression will be operated on. The type of the context is implementation-dependent. If the value is `null`, the operation must have no dependency on the context, otherwise an XPathExpressionException will be thrown. Implementation Note The type of the context is usually `org.w3c.dom.Node`. Parameters item:Object The context the XPath expression will be evaluated in. Returns:String The result of evaluating an XPath expression as a `String`. Exceptions XPathExpressionException: If the expression cannot be evaluated.

public String evaluate(Object item) throws XPathExpressionException

Evaluate the compiled XPath expression in the specified context and return the result as a String.

This method calls evaluate(Object item, QName returnType) with a returnType of XPathConstants#STRING.

See Evaluation of XPath Expressions for context item evaluation, variable, function and QName resolution and return type conversion.

Implementation Note

The type of the context is usually org.w3c.dom.Node.

Parameters

item:Object: The context the XPath expression will be evaluated in.

Returns:String

The result of evaluating an XPath expression as a String.

Exceptions

XPathExpressionException:: If the expression cannot be evaluated.

evaluate back to summary

evaluate	back to summary
public Object evaluate(InputSource source, QName returnType) throws XPathExpressionException Evaluate the compiled XPath expression in the context of the specified `InputSource` and return the result as the specified type. This method builds a data model for the `InputSource` and calls `evaluate(Object item, QName returnType)` on the resulting document object. See Evaluation of XPath Expressions for context item evaluation, variable, function and QName resolution and return type conversion. If `returnType` is not one of the types defined in `XPathConstants`, then an `IllegalArgumentException` is thrown. If `source` or `returnType` is `null`, then a `NullPointerException` is thrown. Parameters source:InputSource The `InputSource` of the document to evaluate over. returnType:QName The desired return type. Returns:Object The `Object` that is the result of evaluating the expression and converting the result to `returnType`. Exceptions XPathExpressionException: If the expression cannot be evaluated. IllegalArgumentException: If `returnType` is not one of the types defined in `XPathConstants`. NullPointerException: If `source or returnType` is `null`.

public Object evaluate(InputSource source, QName returnType) throws XPathExpressionException

Evaluate the compiled XPath expression in the context of the specified InputSource and return the result as the specified type.

This method builds a data model for the InputSource and calls evaluate(Object item, QName returnType) on the resulting document object.

See Evaluation of XPath Expressions for context item evaluation, variable, function and QName resolution and return type conversion.

If returnType is not one of the types defined in XPathConstants, then an IllegalArgumentException is thrown.

If source or returnType is null, then a NullPointerException is thrown.

Parameters

source:InputSource: The InputSource of the document to evaluate over.
returnType:QName: The desired return type.

Returns:Object

The Object that is the result of evaluating the expression and converting the result to returnType.

Exceptions

XPathExpressionException:: If the expression cannot be evaluated.
IllegalArgumentException:: If returnType is not one of the types defined in XPathConstants.
NullPointerException:: If source or returnType is null.

evaluate back to summary

evaluate	back to summary
public String evaluate(InputSource source) throws XPathExpressionException Evaluate the compiled XPath expression in the context of the specified `InputSource` and return the result as a `String`. This method calls `evaluate(InputSource source, QName returnType)` with a `returnType` of `XPathConstants#STRING`. See Evaluation of XPath Expressions for context item evaluation, variable, function and QName resolution and return type conversion. If `source` is `null`, then a `NullPointerException` is thrown. Parameters source:InputSource The `InputSource` of the document to evaluate over. Returns:String The `String` that is the result of evaluating the expression and converting the result to a `String`. Exceptions XPathExpressionException: If the expression cannot be evaluated. NullPointerException: If `source` is `null`.

public String evaluate(InputSource source) throws XPathExpressionException

Evaluate the compiled XPath expression in the context of the specified InputSource and return the result as a String.

This method calls evaluate(InputSource source, QName returnType) with a returnType of XPathConstants#STRING.

See Evaluation of XPath Expressions for context item evaluation, variable, function and QName resolution and return type conversion.

If source is null, then a NullPointerException is thrown.

Parameters

source:InputSource: The InputSource of the document to evaluate over.

Returns:String

The String that is the result of evaluating the expression and converting the result to a String.

Exceptions

XPathExpressionException:: If the expression cannot be evaluated.
NullPointerException:: If source is null.

evaluateExpression back to summary

evaluateExpression	back to summary
public default <T> T evaluateExpression(Object item, Class<T> type) throws XPathExpressionException Evaluate the compiled XPath expression in the specified context, and return the result with the type specified through the `class type`. The parameter `item` represents the context the XPath expression will be operated on. The type of the context is implementation-dependent. If the value is `null`, the operation must have no dependency on the context, otherwise an XPathExpressionException will be thrown. Implementation Note The type of the context is usually `org.w3c.dom.Node`. Implementation Specification The default implementation in the XPath API is equivalent to: `(T)evaluate(item, XPathEvaluationResult.XPathResultType.getQNameType(type));` Since the `evaluate` method does not support the `ANY` type, specifying XPathEvaluationResult as the type will result in IllegalArgumentException. Any implementation supporting the `ANY` type must override this method. Parameters <T> The class type that will be returned by the XPath expression. item:Object The context the XPath expression will be evaluated in. type:Class<T> The class type expected to be returned by the XPath expression, must be one of the types described in section 3.2 Class types in the package summary. Returns:T The result of evaluating the expression. Exceptions XPathExpressionException: If the expression cannot be evaluated. IllegalArgumentException: If `type` is not of the types corresponding to the types defined in the `XPathResultType`, or XPathEvaluationResult is specified as the type but an implementation supporting the `ANY` type is not available. NullPointerException: If `type` is `null`. Since 9

public default <T> T evaluateExpression(Object item, Class<T> type) throws XPathExpressionException

Evaluate the compiled XPath expression in the specified context, and return the result with the type specified through the class type.

Implementation Note

The type of the context is usually org.w3c.dom.Node.

Implementation Specification

The default implementation in the XPath API is equivalent to:

 (T)evaluate(item, XPathEvaluationResult.XPathResultType.getQNameType(type));

Since the evaluate method does not support the ANY type, specifying XPathEvaluationResult as the type will result in IllegalArgumentException. Any implementation supporting the ANY type must override this method.

Parameters

<T>: The class type that will be returned by the XPath expression.
item:Object: The context the XPath expression will be evaluated in.
type:Class<T>: The class type expected to be returned by the XPath expression, must be one of the types described in section 3.2 Class types in the package summary.

Returns:T

The result of evaluating the expression.

Exceptions

XPathExpressionException:: If the expression cannot be evaluated.
IllegalArgumentException:: If type is not of the types corresponding to the types defined in the XPathResultType, or XPathEvaluationResult is specified as the type but an implementation supporting the ANY type is not available.
NullPointerException:: If type is null.

Since

evaluateExpression back to summary

evaluateExpression	back to summary
public default XPathEvaluationResult<?> evaluateExpression(Object item) throws XPathExpressionException Evaluate the compiled XPath expression in the specified context. This is equivalent to calling `evaluateExpression(Object item, Class type)` with type `XPathEvaluationResult`: `evaluateExpression(item, XPathEvaluationResult.class);` The parameter `item` represents the context the XPath expression will be operated on. The type of the context is implementation-dependent. If the value is `null`, the operation must have no dependency on the context, otherwise an XPathExpressionException will be thrown. Implementation Note The type of the context is usually `org.w3c.dom.Node`. Implementation Specification The default implementation in the XPath API is equivalent to: `evaluateExpression(item, XPathEvaluationResult.class);` Since the `evaluate` method does not support the `ANY` type, the default implementation of this method will always throw an IllegalArgumentException. Any implementation supporting the `ANY` type must therefore override this method. Parameters item:Object The context the XPath expression will be evaluated in. Returns:XPathEvaluationResult<?> The result of evaluating the expression. Exceptions XPathExpressionException: If the expression cannot be evaluated. IllegalArgumentException: If the implementation of this method does not support the `ANY` type. Since 9

public default XPathEvaluationResult<?> evaluateExpression(Object item) throws XPathExpressionException

Evaluate the compiled XPath expression in the specified context. This is equivalent to calling evaluateExpression(Object item, Class type) with type XPathEvaluationResult:

 evaluateExpression(item, XPathEvaluationResult.class);

Implementation Note

The type of the context is usually org.w3c.dom.Node.

Implementation Specification

The default implementation in the XPath API is equivalent to:

 evaluateExpression(item, XPathEvaluationResult.class);

Since the evaluate method does not support the ANY type, the default implementation of this method will always throw an IllegalArgumentException. Any implementation supporting the ANY type must therefore override this method.

Parameters

item:Object: The context the XPath expression will be evaluated in.

Returns:XPathEvaluationResult<?>

The result of evaluating the expression.

Exceptions

XPathExpressionException:: If the expression cannot be evaluated.
IllegalArgumentException:: If the implementation of this method does not support the ANY type.

Since

evaluateExpression back to summary

evaluateExpression	back to summary
public default <T> T evaluateExpression(InputSource source, Class<T> type) throws XPathExpressionException Evaluate the compiled XPath expression in the specified context, and return the result with the type specified through the `class type` This method builds a data model for the `InputSource` and calls `evaluateExpression(Object item, Class type)` on the resulting document object. By default, the JDK's data model is `org.w3c.dom.Document`. Implementation Specification The default implementation in the XPath API is equivalent to: `(T)evaluate(source, XPathEvaluationResult.XPathResultType.getQNameType(type));` Since the `evaluate` method does not support the `ANY` type, specifying XPathEvaluationResult as the type will result in IllegalArgumentException. Any implementation supporting the `ANY` type must override this method. Parameters <T> The class type that will be returned by the XPath expression. source:InputSource The `InputSource` of the document to evaluate over. type:Class<T> The class type expected to be returned by the XPath expression, must be one of the types described in section 3.2 Class types in the package summary. Returns:T The result of evaluating the expression. Exceptions XPathExpressionException: If the expression cannot be evaluated. IllegalArgumentException: If `type` is not of the types corresponding to the types defined in the `XPathResultType`, or XPathEvaluationResult is specified as the type but an implementation supporting the `ANY` type is not available. NullPointerException: If `source or type` is `null`. Since 9

public default <T> T evaluateExpression(InputSource source, Class<T> type) throws XPathExpressionException

Evaluate the compiled XPath expression in the specified context, and return the result with the type specified through the class type

This method builds a data model for the InputSource and calls evaluateExpression(Object item, Class type) on the resulting document object.

By default, the JDK's data model is org.w3c.dom.Document.

Implementation Specification

The default implementation in the XPath API is equivalent to:

 (T)evaluate(source, XPathEvaluationResult.XPathResultType.getQNameType(type));

Parameters

<T>: The class type that will be returned by the XPath expression.
source:InputSource: The InputSource of the document to evaluate over.
type:Class<T>: The class type expected to be returned by the XPath expression, must be one of the types described in section 3.2 Class types in the package summary.

Returns:T

The result of evaluating the expression.

Exceptions

XPathExpressionException:: If the expression cannot be evaluated.
IllegalArgumentException:: If type is not of the types corresponding to the types defined in the XPathResultType, or XPathEvaluationResult is specified as the type but an implementation supporting the ANY type is not available.
NullPointerException:: If source or type is null.

Since

evaluateExpression back to summary

evaluateExpression	back to summary
public default XPathEvaluationResult<?> evaluateExpression(InputSource source) throws XPathExpressionException Evaluate the compiled XPath expression in the specified context. This is equivalent to calling `evaluateExpression(InputSource source, Class type)` with type `XPathEvaluationResult`: `evaluateExpression(source, XPathEvaluationResult.class);` Implementation Specification The default implementation in the XPath API is equivalent to: `(XPathEvaluationResult)evaluateExpression(source, XPathEvaluationResult.class);` Since the `evaluate` method does not support the `ANY` type, the default implementation of this method will always throw an IllegalArgumentException. Any implementation supporting the `ANY` type must therefore override this method. Parameters source:InputSource The `InputSource` of the document to evaluate over. Returns:XPathEvaluationResult<?> The result of evaluating the expression. Exceptions XPathExpressionException: If the expression cannot be evaluated. IllegalArgumentException: If the implementation of this method does not support the `ANY` type. NullPointerException: If `source` is `null`. Since 9

public default XPathEvaluationResult<?> evaluateExpression(InputSource source) throws XPathExpressionException

Evaluate the compiled XPath expression in the specified context. This is equivalent to calling evaluateExpression(InputSource source, Class type) with type XPathEvaluationResult:

 evaluateExpression(source, XPathEvaluationResult.class);

Implementation Specification

The default implementation in the XPath API is equivalent to:

 (XPathEvaluationResult)evaluateExpression(source, XPathEvaluationResult.class);

Parameters

source:InputSource: The InputSource of the document to evaluate over.

Returns:XPathEvaluationResult<?>

The result of evaluating the expression.

Exceptions

XPathExpressionException:: If the expression cannot be evaluated.
IllegalArgumentException:: If the implementation of this method does not support the ANY type.
NullPointerException:: If source is null.

Since

public Interface XPathExpression

Method Summary

Method Detail