JDOM 2.0.6.1 · org.jdom2.xpath.jaxen.JaxenXPathFactory

Access	Constructor and Description
public	JaxenXPathFactory() The public default constructor used by the XPathFactory.

Modifier and Type	Method and Description
public <T> XPathExpression<T>	compile(String The XPath expression. expression, Filter<T> The Filter that is used to coerce the XPath result data in to the generic-typed results. Note that the `Filters` class has a number of predefined, useful filters. filter, Map<String, Object> Any variable values that may be referenced from the query. A null value indicates that there are no variables. variables, Namespace... Any namespaces that may be referenced from the query namespaces) Implements abstract org.jdom2.xpath.XPathFactory.compile. Create a Compiled XPathExpression<> instance from this factory.

JaxenXPathFactory	back to summary
public JaxenXPathFactory() The public default constructor used by the XPathFactory.

Method Detail

compile back to summary

compile	back to summary
public <T> XPathExpression<T> compile(String expression, Filter<T> filter, Map<String, Object> variables, Namespace... namespaces) Implements abstract org.jdom2.xpath.XPathFactory.compile. Doc from org.jdom2.xpath.XPathFactory.compile. Create a Compiled XPathExpression<> instance from this factory. This is the only abstract method on this class. All other compile and evaluate methods prepare the data in some way to call this compile method. XPathFactory implementations override this method to implement support for the JDOM/XPath API. A Filter is used to coerce resulting XPath data in to a suitable JDOM generic type. Note that the `Filters` class has a number of predefined, useful filters. Namespace XPath expressions are always namespace aware, and expect to be able to resolve prefixes to namespace URIs. In XPath expressions the prefix "" always resolves to the empty Namespace URI "". A prefix in an XPath query is expected to resolve to exactly one URI. Multiple different prefixes in the expression may resolve to the same URI. This compile method ensures that these XPath/Namespace rules are followed and thus this method will throw IllegalArgumentException if: a namespace has the empty-string prefix but has a non-empty URI. more than one Namespace has any one prefix. Variables Variables are referenced from XPath expressions using a `$varname` syntax. The variable name may be a Namespace qualified variable name of the form `$pfx:localname`. Variables `$pa:var` and `$pb:var` are the identical variables if the namespace URI for prefix 'pa' is the same URI as for prefix 'pb'. This compile method expects all variable names to be expressed in a prefix-qualified format, where all prefixes have to be available in one of the specified Namespace instances. e.g. if you specify a variable name "ns:var" with value "value", you also need to have some namespace provided with the prefix "ns" such as `Namespace.getNamespace("ns", "http://example.com/nsuri");` Some XPath libraries allow null variable values (Jaxen), some do not (native Java). This compile method will silently convert any null Variable value to an empty string `""`. Variables are provided in the form of a Map where the key is the variable name and the mapped value is the variable value. If the entire map is null then the compile Method assumes there are no variables. In light of the above, this compile method will throw an IllegalArgumentException if: a variable name is not a valid XML QName. The prefix associated with a variable name is not available as a Namespace. A NullPointerException will be thrown if the map contains a null variable name Parameters <T> The generic type of the results that the XPathExpression will produce. expression:String The XPath expression. filter:Filter<T> The Filter that is used to coerce the XPath result data in to the generic-typed results. Note that the `Filters` class has a number of predefined, useful filters. variables:Map<String, Object> Any variable values that may be referenced from the query. A null value indicates that there are no variables. namespaces:Namespace[] Any namespaces that may be referenced from the query Returns:XPathExpression<T> an XPathExpression<> instance. Annotations @Override

public <T> XPathExpression<T> compile(String expression, Filter<T> filter, Map<String, Object> variables, Namespace... namespaces)

Implements abstract org.jdom2.xpath.XPathFactory.compile.

Doc from org.jdom2.xpath.XPathFactory.compile.

Create a Compiled XPathExpression<> instance from this factory. This is the only abstract method on this class. All other compile and evaluate methods prepare the data in some way to call this compile method.

XPathFactory implementations override this method to implement support for the JDOM/XPath API.

A Filter is used to coerce resulting XPath data in to a suitable JDOM generic type. Note that the Filters class has a number of predefined, useful filters.

Namespace

XPath expressions are always namespace aware, and expect to be able to resolve prefixes to namespace URIs. In XPath expressions the prefix "" always resolves to the empty Namespace URI "". A prefix in an XPath query is expected to resolve to exactly one URI. Multiple different prefixes in the expression may resolve to the same URI.

This compile method ensures that these XPath/Namespace rules are followed and thus this method will throw IllegalArgumentException if:

a namespace has the empty-string prefix but has a non-empty URI.
more than one Namespace has any one prefix.

Variables

Variables are referenced from XPath expressions using a $varname syntax. The variable name may be a Namespace qualified variable name of the form $pfx:localname. Variables $pa:var and $pb:var are the identical variables if the namespace URI for prefix 'pa' is the same URI as for prefix 'pb'.

This compile method expects all variable names to be expressed in a prefix-qualified format, where all prefixes have to be available in one of the specified Namespace instances.

e.g. if you specify a variable name "ns:var" with value "value", you also need to have some namespace provided with the prefix "ns" such as Namespace.getNamespace("ns", "http://example.com/nsuri");

Some XPath libraries allow null variable values (Jaxen), some do not (native Java). This compile method will silently convert any null Variable value to an empty string "".

Variables are provided in the form of a Map where the key is the variable name and the mapped value is the variable value. If the entire map is null then the compile Method assumes there are no variables.

In light of the above, this compile method will throw an IllegalArgumentException if:

a variable name is not a valid XML QName.
The prefix associated with a variable name is not available as a Namespace.

A NullPointerException will be thrown if the map contains a null variable name

Parameters

<T>: The generic type of the results that the XPathExpression will produce.
expression:String: The XPath expression.
filter:Filter<T>: The Filter that is used to coerce the XPath result data in to the generic-typed results. Note that the Filters class has a number of predefined, useful filters.
variables:Map<String, Object>: Any variable values that may be referenced from the query. A null value indicates that there are no variables.
namespaces:Namespace[]: Any namespaces that may be referenced from the query

Returns:XPathExpression<T>

an XPathExpression<> instance.

Annotations

@Override

public Class JaxenXPathFactory

Constructor Summary

Method Summary

Constructor Detail

Method Detail

Namespace

Variables