| /* |
| * Copyright (c) 2003, 2017, 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 javax.xml.namespace.NamespaceContext; |
| import javax.xml.namespace.QName; |
| import org.xml.sax.InputSource; |
| |
| /** |
| * {@code XPath} provides access to the XPath evaluation environment and expressions. |
| * The XPath evaluation is affected by the factors described in the following table. |
| * |
| * <a id="XPath-evaluation"></a> |
| * <table class="striped"> |
| * <caption>Evaluation of XPath Expressions</caption> |
| * <thead> |
| * <tr> |
| * <th>Factor</th> |
| * <th>Behavior</th> |
| * </tr> |
| * </thead> |
| * <tbody> |
| * <tr> |
| * <td>context</td> |
| * <td> |
| * The type of the context is implementation-dependent. If the value is |
| * null, the operation must have no dependency on the context, otherwise |
| * an XPathExpressionException will be thrown. |
| * |
| * For the purposes of evaluating XPath expressions, a DocumentFragment |
| * is treated like a Document node. |
| * </td> |
| * </tr> |
| * <tr> |
| * <td>variables</td> |
| * <td> |
| * If the expression contains a variable reference, its value will be found through the {@link XPathVariableResolver} |
| * set with {@link #setXPathVariableResolver(XPathVariableResolver resolver)}. |
| * An {@link XPathExpressionException} is raised if the variable resolver is undefined or |
| * the resolver returns {@code null} for the variable. |
| * The value of a variable must be immutable through the course of any single evaluation. |
| * </td> |
| * </tr> |
| * <tr> |
| * <td>functions</td> |
| * <td> |
| * If the expression contains a function reference, the function will be found through the {@link XPathFunctionResolver} |
| * set with {@link #setXPathFunctionResolver(XPathFunctionResolver resolver)}. |
| * An {@link XPathExpressionException} is raised if the function resolver is undefined or |
| * the function resolver returns {@code null} for the function. |
| * </td> |
| * </tr> |
| * <tr> |
| * <td>QNames</td> |
| * <td> |
| * QNames in the expression are resolved against the XPath namespace context |
| * set with {@link #setNamespaceContext(NamespaceContext nsContext)}. |
| * </td> |
| * </tr> |
| * <tr> |
| * <td>result</td> |
| * <td> |
| * This result of evaluating an expression is converted to an instance of the desired return type. |
| * Valid return types are defined in {@link XPathConstants}. |
| * Conversion to the return type follows XPath conversion rules. |
| * </td> |
| * </tr> |
| * </tbody> |
| * </table> |
| * |
| * <p>An XPath object is not thread-safe and not reentrant. |
| * In other words, it is the application's responsibility to make |
| * sure that one {@link XPath} object is not used from |
| * more than one thread at any given time, and while the {@code evaluate} |
| * method is invoked, applications may not recursively call |
| * the {@code evaluate} method. |
| * |
| * @author <a href="Norman.Walsh@Sun.com">Norman Walsh</a> |
| * @author <a href="Jeff.Suttor@Sun.com">Jeff Suttor</a> |
| * @see <a href="http://www.w3.org/TR/xpath">XML Path Language (XPath) Version 1.0</a> |
| * @since 1.5 |
| */ |
| public interface XPath { |
| |
| |
| /** |
| * Reset this {@code XPath} to its original configuration. |
| * |
| * <p>{@code XPath} is reset to the same state as when it was created with |
| * {@link XPathFactory#newXPath()}. |
| * {@code reset()} is designed to allow the reuse of existing {@code XPath}s |
| * thus saving resources associated with the creation of new {@code XPath}s. |
| * |
| * <p>The reset {@code XPath} is not guaranteed to have the same |
| * {@link XPathFunctionResolver}, {@link XPathVariableResolver} |
| * or {@link NamespaceContext} {@code Object}s, e.g. {@link Object#equals(Object obj)}. |
| * It is guaranteed to have a functionally equal {@code XPathFunctionResolver}, |
| * {@code XPathVariableResolver} and {@code NamespaceContext}. |
| */ |
| public void reset(); |
| |
| /** |
| * Establish a variable resolver. |
| * |
| * <p>A {@code NullPointerException} is thrown if {@code resolver} is {@code null}. |
| * |
| * @param resolver Variable resolver. |
| * |
| * @throws NullPointerException If {@code resolver} is {@code null}. |
| */ |
| public void setXPathVariableResolver(XPathVariableResolver resolver); |
| |
| /** |
| * Return the current variable resolver. |
| * |
| * <p>{@code null} is returned in no variable resolver is in effect. |
| * |
| * @return Current variable resolver. |
| */ |
| public XPathVariableResolver getXPathVariableResolver(); |
| |
| /** |
| * Establish a function resolver. |
| * |
| * <p>A {@code NullPointerException} is thrown if {@code resolver} is {@code null}. |
| * |
| * @param resolver XPath function resolver. |
| * |
| * @throws NullPointerException If {@code resolver} is {@code null}. |
| */ |
| public void setXPathFunctionResolver(XPathFunctionResolver resolver); |
| |
| /** |
| * Return the current function resolver. |
| * <p> |
| * {@code null} is returned in no function resolver is in effect. |
| * |
| * @return Current function resolver. |
| */ |
| public XPathFunctionResolver getXPathFunctionResolver(); |
| |
| /** |
| * Establish a namespace context. |
| * |
| * <p>A {@code NullPointerException} is thrown if {@code nsContext} is {@code null}. |
| * |
| * @param nsContext Namespace context to use. |
| * |
| * @throws NullPointerException If {@code nsContext} is {@code null}. |
| */ |
| public void setNamespaceContext(NamespaceContext nsContext); |
| |
| /** |
| * Return the current namespace context. |
| * |
| * <p>{@code null} is returned in no namespace context is in effect. |
| * |
| * @return Current Namespace context. |
| */ |
| public NamespaceContext getNamespaceContext(); |
| |
| /** |
| * Compile an XPath expression for later evaluation. |
| * |
| * <p>If {@code expression} contains any {@link XPathFunction}s, |
| * they must be available via the {@link XPathFunctionResolver}. |
| * An {@link XPathExpressionException} will be thrown if the |
| * {@code XPathFunction} |
| * cannot be resovled with the {@code XPathFunctionResolver}. |
| * |
| * <p>If {@code expression} contains any variables, the |
| * {@link XPathVariableResolver} in effect |
| * <strong>at compile time</strong> will be used to resolve them. |
| * |
| * @param expression The XPath expression. |
| * |
| * @return Compiled XPath expression. |
| |
| * @throws XPathExpressionException If {@code expression} cannot be compiled. |
| * @throws NullPointerException If {@code expression} is {@code null}. |
| */ |
| public XPathExpression compile(String expression) |
| throws XPathExpressionException; |
| |
| /** |
| * Evaluate an {@code XPath} expression in the specified context and |
| * return the result as the specified type. |
| * |
| * <p> |
| * See <a href="#XPath-evaluation">Evaluation of XPath Expressions</a> |
| * for context item evaluation, variable, function and {@code QName} resolution |
| * and return type conversion. |
| * <p> |
| * The parameter {@code item} represents the context the XPath expression |
| * will be operated on. The type of the context is implementation-dependent. |
| * If the value is {@code null}, the operation must have no dependency on |
| * the context, otherwise an XPathExpressionException will be thrown. |
| * |
| * @implNote |
| * The type of the context is usually {@link org.w3c.dom.Node}. |
| * |
| * @param expression The XPath expression. |
| * @param item The context the XPath expression will be evaluated in. |
| * @param returnType The result type expected to be returned by the XPath expression. |
| * |
| * @return The result of evaluating an XPath expression as an {@code Object} of {@code returnType}. |
| * |
| * @throws XPathExpressionException If {@code expression} cannot be evaluated. |
| * @throws IllegalArgumentException If {@code returnType} is not one of the types defined in {@link XPathConstants} ( |
| * {@link XPathConstants#NUMBER NUMBER}, |
| * {@link XPathConstants#STRING STRING}, |
| * {@link XPathConstants#BOOLEAN BOOLEAN}, |
| * {@link XPathConstants#NODE NODE} or |
| * {@link XPathConstants#NODESET NODESET}). |
| * @throws NullPointerException If {@code expression or returnType} is {@code null}. |
| */ |
| public Object evaluate(String expression, Object item, QName returnType) |
| throws XPathExpressionException; |
| |
| /** |
| * Evaluate an XPath expression in the specified context and return the result as a {@code String}. |
| * |
| * <p>This method calls {@link #evaluate(String expression, Object item, QName returnType)} with a {@code returnType} of |
| * {@link XPathConstants#STRING}. |
| * |
| * <p>See <a href="#XPath-evaluation">Evaluation of XPath Expressions</a> for context item evaluation, |
| * variable, function and QName resolution and return type conversion. |
| * |
| * <p> |
| * The parameter {@code item} represents the context the XPath expression |
| * will be operated on. The type of the context is implementation-dependent. |
| * If the value is {@code null}, the operation must have no dependency on |
| * the context, otherwise an XPathExpressionException will be thrown. |
| * |
| * @implNote |
| * The type of the context is usually {@link org.w3c.dom.Node}. |
| * |
| * @param expression The XPath expression. |
| * @param item The context the XPath expression will be evaluated in. |
| * |
| * @return The result of evaluating an XPath expression as a {@code String}. |
| * |
| * @throws XPathExpressionException If {@code expression} cannot be evaluated. |
| * @throws NullPointerException If {@code expression} is {@code null}. |
| */ |
| public String evaluate(String expression, Object item) |
| throws XPathExpressionException; |
| |
| /** |
| * Evaluate an XPath expression in the context of the specified {@code InputSource} |
| * and return the result as the specified type. |
| * |
| * <p>This method builds a data model for the {@link InputSource} and calls |
| * {@link #evaluate(String expression, Object item, QName returnType)} on the resulting document object. |
| * |
| * <p>See <a href="#XPath-evaluation">Evaluation of XPath Expressions</a> for context item evaluation, |
| * variable, function and QName resolution and return type conversion. |
| * |
| * @param expression The XPath expression. |
| * @param source The input source of the document to evaluate over. |
| * @param returnType The desired return type. |
| * |
| * @return The {@code Object} that encapsulates the result of evaluating the expression. |
| * |
| * @throws XPathExpressionException If expression cannot be evaluated. |
| * @throws IllegalArgumentException If {@code returnType} is not one of the types defined in {@link XPathConstants}. |
| * @throws NullPointerException If {@code expression, source or returnType} is {@code null}. |
| */ |
| public Object evaluate( |
| String expression, |
| InputSource source, |
| QName returnType) |
| throws XPathExpressionException; |
| |
| /** |
| * Evaluate an XPath expression in the context of the specified {@code InputSource} |
| * and return the result as a {@code String}. |
| * |
| * <p>This method calls {@link #evaluate(String expression, InputSource source, QName returnType)} with a |
| * {@code returnType} of {@link XPathConstants#STRING}. |
| * |
| * <p>See <a href="#XPath-evaluation">Evaluation of XPath Expressions</a> for context item evaluation, |
| * variable, function and QName resolution and return type conversion. |
| * |
| * @param expression The XPath expression. |
| * @param source The {@code InputSource} of the document to evaluate over. |
| * |
| * @return The {@code String} that is the result of evaluating the expression and |
| * converting the result to a {@code String}. |
| * |
| * @throws XPathExpressionException If expression cannot be evaluated. |
| * @throws NullPointerException If {@code expression or source} is {@code null}. |
| */ |
| public String evaluate(String expression, InputSource source) |
| throws XPathExpressionException; |
| |
| /** |
| * Evaluate an XPath expression in the specified context and return |
| * the result with the type specified through the {@code class type} |
| * |
| * <p> |
| * The parameter {@code item} represents the context the XPath expression |
| * will be operated on. The type of the context is implementation-dependent. |
| * If the value is {@code null}, the operation must have no dependency on |
| * the context, otherwise an XPathExpressionException will be thrown. |
| * |
| * @implNote |
| * The type of the context is usually {@link org.w3c.dom.Node}. |
| * |
| * @implSpec |
| * The default implementation in the XPath API is equivalent to: |
| * <pre> {@code |
| * (T)evaluate(expression, item, |
| * XPathEvaluationResult.XPathResultType.getQNameType(type)); |
| * }</pre> |
| * |
| * Since the {@code evaluate} method does not support the |
| * {@link XPathEvaluationResult.XPathResultType#ANY ANY} type, specifying |
| * XPathEvaluationResult as the type will result in IllegalArgumentException. |
| * Any implementation supporting the |
| * {@link XPathEvaluationResult.XPathResultType#ANY ANY} type must override |
| * this method. |
| * |
| * @param <T> The class type that will be returned by the XPath expression. |
| * @param expression The XPath expression. |
| * @param item The context the XPath expression will be evaluated in. |
| * @param type The class type expected to be returned by the XPath expression. |
| * |
| * @return The result of evaluating the expression. |
| * |
| * @throws XPathExpressionException If the expression cannot be evaluated. |
| * @throws IllegalArgumentException If {@code type} is not of the types |
| * corresponding to the types defined in the {@link XPathEvaluationResult.XPathResultType}, |
| * or XPathEvaluationResult is specified as the type but an implementation supporting the |
| * {@link XPathEvaluationResult.XPathResultType#ANY ANY} type is not available. |
| * @throws NullPointerException If {@code expression or type} is {@code null}. |
| * |
| * @since 9 |
| */ |
| default <T>T evaluateExpression(String expression, Object item, Class<T> type) |
| throws XPathExpressionException { |
| return type.cast(evaluate(expression, item, |
| XPathEvaluationResult.XPathResultType.getQNameType(type))); |
| } |
| |
| /** |
| * Evaluate an XPath expression in the specified context. This is equivalent to |
| * calling {@link #evaluateExpression(String expression, Object item, Class type)} |
| * with type {@link XPathEvaluationResult}: |
| * <pre> {@code |
| * evaluateExpression(expression, item, XPathEvaluationResult.class); |
| * }</pre> |
| * <p> |
| * The parameter {@code item} represents the context the XPath expression |
| * will be operated on. The type of the context is implementation-dependent. |
| * If the value is {@code null}, the operation must have no dependency on |
| * the context, otherwise an XPathExpressionException will be thrown. |
| * |
| * @implNote |
| * The type of the context is usually {@link org.w3c.dom.Node}. |
| * |
| * @implSpec |
| * The default implementation in the XPath API is equivalent to: |
| * <pre> {@code |
| * evaluateExpression(expression, item, XPathEvaluationResult.class); |
| * }</pre> |
| * |
| * Since the {@code evaluate} method does not support the |
| * {@link XPathEvaluationResult.XPathResultType#ANY ANY} |
| * type, the default implementation of this method will always throw an |
| * IllegalArgumentException. Any implementation supporting the |
| * {@link XPathEvaluationResult.XPathResultType#ANY ANY} type must therefore |
| * override this method. |
| * |
| * @param expression The XPath expression. |
| * @param item The context the XPath expression will be evaluated in. |
| * |
| * @return The result of evaluating the expression. |
| * |
| * @throws XPathExpressionException If the expression cannot be evaluated. |
| * @throws IllegalArgumentException If the implementation of this method |
| * does not support the |
| * {@link XPathEvaluationResult.XPathResultType#ANY ANY} type. |
| * @throws NullPointerException If {@code expression} is {@code null}. |
| * |
| * @since 9 |
| */ |
| default XPathEvaluationResult<?> evaluateExpression(String expression, Object item) |
| throws XPathExpressionException |
| { |
| return evaluateExpression(expression, item, XPathEvaluationResult.class); |
| } |
| |
| /** |
| * Evaluate an XPath expression in the context of the specified {@code source} |
| * and return the result as specified. |
| * <p> |
| * This method builds a data model for the {@link InputSource} and calls |
| * {@link #evaluateExpression(String expression, Object item, Class type)} |
| * on the resulting document object. The data model is usually |
| * {@link org.w3c.dom.Document} |
| * |
| * @implSpec |
| * The default implementation in the XPath API is equivalent to: |
| * <pre> {@code |
| (T)evaluate(expression, source, |
| XPathEvaluationResult.XPathResultType.getQNameType(type)); |
| * }</pre> |
| * |
| * Since the {@code evaluate} method does not support the |
| * {@link XPathEvaluationResult.XPathResultType#ANY ANY} type, specifying |
| * XPathEvaluationResult as the type will result in IllegalArgumentException. |
| * Any implementation supporting the |
| * {@link XPathEvaluationResult.XPathResultType#ANY ANY} type must override |
| * this method. |
| * |
| * @param <T> The class type that will be returned by the XPath expression. |
| * @param expression The XPath expression. |
| * @param source The input source of the document to evaluate over. |
| * @param type The class type expected to be returned by the XPath expression. |
| * |
| * @return The result of evaluating the expression. |
| * |
| * @throws XPathExpressionException If the expression cannot be evaluated. |
| * @throws IllegalArgumentException If {@code type} is not of the types |
| * corresponding to the types defined in the {@link XPathEvaluationResult.XPathResultType |
| * XPathResultType}, or XPathEvaluationResult is specified as the type but an |
| * implementation supporting the |
| * {@link XPathEvaluationResult.XPathResultType#ANY ANY} type is not available. |
| * @throws NullPointerException If {@code expression, source or type}is {@code null}. |
| * |
| * @since 9 |
| */ |
| default <T>T evaluateExpression(String expression, InputSource source, Class<T> type) |
| throws XPathExpressionException |
| { |
| return type.cast(evaluate(expression, source, |
| XPathEvaluationResult.XPathResultType.getQNameType(type))); |
| } |
| |
| /** |
| * Evaluate an XPath expression in the specified context. This is equivalent to |
| * calling {@link #evaluateExpression(String expression, Object item, Class type)} |
| * with type {@link XPathEvaluationResult}: |
| * <pre> {@code |
| * evaluateExpression(expression, item, XPathEvaluationResult.class); |
| * }</pre> |
| * |
| * @implSpec |
| * The default implementation in the XPath API is equivalent to: |
| * <pre> {@code |
| * evaluateExpression(expression, source, XPathEvaluationResult.class); |
| * }</pre> |
| * |
| * Since the {@code evaluate} method does not support the |
| * {@link XPathEvaluationResult.XPathResultType#ANY ANY} |
| * type, the default implementation of this method will always throw an |
| * IllegalArgumentException. Any implementation supporting the |
| * {@link XPathEvaluationResult.XPathResultType#ANY ANY} type must therefore |
| * override this method. |
| * |
| * @param expression The XPath expression. |
| * @param source The input source of the document to evaluate over. |
| * |
| * @return The result of evaluating the expression. |
| * |
| * @throws XPathExpressionException If the expression cannot be evaluated. |
| * @throws IllegalArgumentException If the implementation of this method |
| * does not support the |
| * {@link XPathEvaluationResult.XPathResultType#ANY ANY} type. |
| * @throws NullPointerException If {@code expression or source} is {@code null}. |
| * |
| * @since 9 |
| */ |
| default XPathEvaluationResult<?> evaluateExpression(String expression, InputSource source) |
| throws XPathExpressionException |
| { |
| return evaluateExpression(expression, source, XPathEvaluationResult.class); |
| } |
| } |
