| /* |
| * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| package javax.xml.xpath; |
| |
| import java.util.Objects; |
| import javax.xml.namespace.QName; |
| import org.w3c.dom.Node; |
| /** |
| * 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 |
| * {@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 {@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 {@link Boolean}. |
| */ |
| BOOLEAN(XPathConstants.BOOLEAN, Boolean.class), |
| /** |
| * 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 {@link String}. |
| */ |
| STRING(XPathConstants.STRING, String.class), |
| /** |
| * 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 {@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. |
| * @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 {@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 {@code XPathResultType} |
| * @return the result type |
| */ |
| public XPathResultType type(); |
| |
| /** |
| * Returns the value of the result as the type {@code <T>} specified for the class. |
| * |
| * @return The value of the result. |
| */ |
| public T value(); |
| |
| } |