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package com.sun.org.apache.xpath.internal.jaxp;

import com.sun.org.apache.xpath.internal.objects.XObject;
import java.util.Objects;
import javax.xml.transform.TransformerException;
import javax.xml.xpath.XPathNodes;
import javax.xml.xpath.XPathEvaluationResult;
import javax.xml.xpath.XPathEvaluationResult.XPathResultType;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.w3c.dom.traversal.NodeIterator;


This is the implementation of XPathEvaluationResult that represents the result of the evaluation of an XPath expression within the context of a particular node.
/** * This is the implementation of XPathEvaluationResult that represents the * result of the evaluation of an XPath expression within the context of a * particular node. */
class XPathResultImpl<T> implements XPathEvaluationResult<T> { XObject resultObject; int resultType; Class<T> type; XPathResultType mapToType; NodeList nodeList = null; int currentIndex; Node currentNode; boolean boolValue = false; Node node = null; double numValue; String strValue;
Construct an XPathEvaluationResult object.
Params:
  • resultObject – internal XPath result object
  • type – class type
Throws:
/** * Construct an XPathEvaluationResult object. * * @param resultObject internal XPath result object * @param type class type * @throws TransformerException if there is an error reading the XPath * result. */
public XPathResultImpl(XObject resultObject, Class<T> type) throws TransformerException { this.resultObject = resultObject; resultType = resultObject.getType(); this.type = type; getResult(resultObject); }
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 */
@Override public XPathResultType type() { return mapToType; }
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 &lt;T&gt; specified for the class. * * @return The value of the result. */
@Override public T value() { Objects.requireNonNull(type); try { return getValue(resultObject, type); } catch (TransformerException ex) { throw new RuntimeException(ex); } }
Read the XObject and set values in accordance with the result type
Params:
  • resultObject – internal XPath result object
Throws:
/** * Read the XObject and set values in accordance with the result type * @param resultObject internal XPath result object * @throws TransformerException if there is an error reading the XPath * result. */
private void getResult(XObject resultObject) throws TransformerException { switch (resultType) { case XObject.CLASS_BOOLEAN: boolValue = resultObject.bool(); mapToType = XPathResultType.BOOLEAN; break; case XObject.CLASS_NUMBER: numValue = resultObject.num(); mapToType = XPathResultType.NUMBER; break; case XObject.CLASS_STRING: strValue = resultObject.str(); mapToType = XPathResultType.STRING; break; case XObject.CLASS_NODESET: mapToType = XPathResultType.NODESET; nodeList = resultObject.nodelist(); break; case XObject.CLASS_RTREEFRAG: //NODE mapToType = XPathResultType.NODE; NodeIterator ni = resultObject.nodeset(); //Return the first node, or null node = ni.nextNode(); break; } }
Read the internal result object and return the value in accordance with the type specified.
Params:
  • resultObject – internal XPath result object
  • type – the class type
Type parameters:
  • <T> – The expected class type.
Throws:
Returns:The value of the result, null in case of unexpected type.
/** * Read the internal result object and return the value in accordance with * the type specified. * * @param <T> The expected class type. * @param resultObject internal XPath result object * @param type the class type * @return The value of the result, null in case of unexpected type. * @throws TransformerException if there is an error reading the XPath * result. */
static <T> T getValue(XObject resultObject, Class<T> type) throws TransformerException { Objects.requireNonNull(type); if (type.isAssignableFrom(XPathEvaluationResult.class)) { return type.cast(new XPathResultImpl<T>(resultObject, type)); } int resultType = classToInternalType(type); switch (resultType) { case XObject.CLASS_BOOLEAN: return type.cast(resultObject.bool()); case XObject.CLASS_NUMBER: if (Double.class.isAssignableFrom(type)) { return type.cast(resultObject.num()); } else if (Integer.class.isAssignableFrom(type)) { return type.cast((int)resultObject.num()); } else if (Long.class.isAssignableFrom(type)) { return type.cast((long)resultObject.num()); } /* This is to suppress warnings. By the current specification, among numeric types, only Double, Integer and Long are supported. */ break; case XObject.CLASS_STRING: return type.cast(resultObject.str()); case XObject.CLASS_NODESET: XPathNodes nodeSet = new XPathNodesImpl(resultObject.nodelist(), Node.class); return type.cast(nodeSet); case XObject.CLASS_RTREEFRAG: //NODE NodeIterator ni = resultObject.nodeset(); //Return the first node, or null return type.cast(ni.nextNode()); } return null; }
Map the specified class type to the internal result type
Params:
  • type – the class type
Type parameters:
  • <T> – The expected class type.
Returns:the internal XObject type.
/** * Map the specified class type to the internal result type * * @param <T> The expected class type. * @param type the class type * @return the internal XObject type. */
static <T> int classToInternalType(Class<T> type) { if (type.isAssignableFrom(Boolean.class)) { return XObject.CLASS_BOOLEAN; } else if (Number.class.isAssignableFrom(type)) { return XObject.CLASS_NUMBER; } else if (type.isAssignableFrom(String.class)) { return XObject.CLASS_STRING; } else if (type.isAssignableFrom(XPathNodes.class)) { return XObject.CLASS_NODESET; } else if (type.isAssignableFrom(Node.class)) { return XObject.CLASS_RTREEFRAG; } return XObject.CLASS_NULL; } }