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package javax.xml.xpath;
import java.util.Objects;
import javax.xml.namespace.QName;
import org.w3c.dom.Node;
The XPathEvaluationResult interface represents the result of the evaluation of an XPath expression within the context of a particular node. The evaluation of an XPath expression can result in various result types as defined in XML Path Language (XPath) Version 1.0. Type parameters: - <T> – the object type returned by the XPath evaluation.
See Also: Since: 9
/**
* The {@code XPathEvaluationResult} interface represents the result of the
* evaluation of an XPath expression within the context of a particular node.
* The evaluation of an XPath expression can result in various result types as
* defined in XML Path Language (XPath) Version 1.0.
*
* @param <T> the object type returned by the XPath evaluation.
* @see <a href="http://www.w3.org/TR/xpath">XML Path Language (XPath) Version
* 1.0</a>
*
* @since 9
*/
public interface XPathEvaluationResult<T> {
XPathResultType represents possible return types of an XPath evaluation. Provided as an enum type, it allows the use of switch statement. At the same time, a mapping is provided between the original QName types in XPathConstants and class types used in the generic methods. /**
* XPathResultType represents possible return types of an XPath evaluation.
* Provided as an enum type, it allows the use of switch statement. At the
* same time, a mapping is provided between the original QName types in
* {@link XPathConstants} and class types used in the generic methods.
*/
public static enum XPathResultType {
Any type that represents any of the 5 other types listed below. Maps to XPathEvaluationResult. /**
* Any type that represents any of the 5 other types listed below.
* Maps to {@link XPathEvaluationResult}.
*/
ANY(new QName("http://www.w3.org/1999/XSL/Transform", "any"), XPathEvaluationResult.class),
The XPath 1.0 boolean data type. Maps to Java Boolean. /**
* The XPath 1.0 boolean data type. Maps to Java {@link Boolean}.
*/
BOOLEAN(XPathConstants.BOOLEAN, Boolean.class),
The XPath 1.0 Number data type. Maps to Java Number. Of the subtypes of Number, only Double, Integer and Long are required. /**
* The XPath 1.0 Number data type. Maps to Java {@link Number}. Of the
* subtypes of Number, only Double, Integer and Long are required.
*/
NUMBER(XPathConstants.NUMBER, Number.class),
The XPath 1.0 String data type. Maps to Java String. /**
* The XPath 1.0 String data type. Maps to Java {@link String}.
*/
STRING(XPathConstants.STRING, String.class),
The XPath 1.0 NodeSet data type. Maps to NodeList. /**
* The XPath 1.0 NodeSet data type. Maps to {@link org.w3c.dom.NodeList}.
*/
NODESET(XPathConstants.NODESET, XPathNodes.class),
The XPath 1.0 NodeSet data type. Maps to Node. /**
* The XPath 1.0 NodeSet data type. Maps to {@link org.w3c.dom.Node}.
*/
NODE(XPathConstants.NODE, Node.class);
final QName qnameType;
final Class<?> clsType;
XPathResultType(QName qnameType, Class<?> clsType) {
this.qnameType = qnameType;
this.clsType = clsType;
}
Compares this type to the specified class type.
Params: - clsType – class type
Returns: true if the argument is not null and is a class type that
matches that this type represents, false otherwise.
/**
* Compares this type to the specified class type.
* @param clsType class type
* @return true if the argument is not null and is a class type that
* matches that this type represents, false otherwise.
*/
private boolean equalsClassType(Class<?> clsType) {
Objects.nonNull(clsType);
if (clsType.isAssignableFrom(this.clsType)) {
return true;
}
return false;
}
Returns the QName type as specified in XPathConstants that corresponds to the specified class type. Params: - clsType – a class type that the enum type supports
Returns: the QName type that matches with the specified class type,
null if there is no match
/**
* Returns the QName type as specified in {@link XPathConstants} that
* corresponds to the specified class type.
* @param clsType a class type that the enum type supports
* @return the QName type that matches with the specified class type,
* null if there is no match
*/
static public QName getQNameType(Class<?> clsType) {
for (XPathResultType type : XPathResultType.values()) {
if (type.equalsClassType(clsType)) {
return type.qnameType;
}
}
return null;
}
}
Return the result type as an enum specified by XPathResultType Returns: the result type
/**
* Return the result type as an enum specified by {@code XPathResultType}
* @return the result type
*/
public XPathResultType type();
Returns the value of the result as the type <T> specified for the class. Returns: The value of the result.
/**
* Returns the value of the result as the type {@code <T>} specified for the class.
*
* @return The value of the result.
*/
public T value();
}