20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package javax.xml.xpath;
  27 
  28 import javax.xml.namespace.QName;
  29 
  30 /**
  31  * <p><code>XPathVariableResolver</code> provides access to the set of user defined XPath variables.</p>
  32  *
  33  * <p>The <code>XPathVariableResolver</code> and the XPath evaluator must adhere to a contract that
  34  * cannot be directly enforced by the API.  Although variables may be mutable,
  35  * that is, an application may wish to evaluate the same XPath expression more
  36  * than once with different variable values, in the course of evaluating any
  37  * single XPath expression, a variable's value <strong><em>must</em></strong>
  38  * not change.</p>
  39  *
  40  * @author  <a href="mailto:Norman.Walsh@Sun.com">Norman Walsh</a>
  41  * @author  <a href="mailto:Jeff.Suttor@Sun.com">Jeff Suttor</a>
  42  * @since 1.5
  43  */
  44 public interface XPathVariableResolver {
  45   /**
  46    * <p>Find a variable in the set of available variables.</p>
  47    *
  48    * <p>If <code>variableName</code> is <code>null</code>, then a <code>NullPointerException</code> is thrown.</p>
  49    *
  50    * @param variableName The <code>QName</code> of the variable name.
  51    *
  52    * @return The variables value, or <code>null</code> if no variable named <code>variableName</code>
  53    *   exists.  The value returned must be of a type appropriate for the underlying object model.
  54    *
  55    * @throws NullPointerException If <code>variableName</code> is <code>null</code>.
  56    */
  57   public Object resolveVariable(QName variableName);
  58 }

  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package javax.xml.xpath;
  27 
  28 import javax.xml.namespace.QName;
  29 
  30 /**
  31  * <p><code>XPathVariableResolver</code> provides access to the set of user defined XPath variables.</p>
  32  *
  33  * <p>The <code>XPathVariableResolver</code> and the XPath evaluator must adhere to a contract that
  34  * cannot be directly enforced by the API.  Although variables may be mutable,
  35  * that is, an application may wish to evaluate the same XPath expression more
  36  * than once with different variable values, in the course of evaluating any
  37  * single XPath expression, a variable's value <strong><em>must</em></strong>
  38  * not change.</p>
  39  *
  40  * @author  Norman Walsh
  41  * @author  Jeff Suttor
  42  * @since 1.5
  43  */
  44 public interface XPathVariableResolver {
  45   /**
  46    * <p>Find a variable in the set of available variables.</p>
  47    *
  48    * <p>If <code>variableName</code> is <code>null</code>, then a <code>NullPointerException</code> is thrown.</p>
  49    *
  50    * @param variableName The <code>QName</code> of the variable name.
  51    *
  52    * @return The variables value, or <code>null</code> if no variable named <code>variableName</code>
  53    *   exists.  The value returned must be of a type appropriate for the underlying object model.
  54    *
  55    * @throws NullPointerException If <code>variableName</code> is <code>null</code>.
  56    */
  57   public Object resolveVariable(QName variableName);
  58 }