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Diffstat (limited to 'common/src/main/java/at/gv/egovernment/moa/util/XPathUtils.java')
-rw-r--r-- | common/src/main/java/at/gv/egovernment/moa/util/XPathUtils.java | 541 |
1 files changed, 541 insertions, 0 deletions
diff --git a/common/src/main/java/at/gv/egovernment/moa/util/XPathUtils.java b/common/src/main/java/at/gv/egovernment/moa/util/XPathUtils.java new file mode 100644 index 000000000..01fe3a3aa --- /dev/null +++ b/common/src/main/java/at/gv/egovernment/moa/util/XPathUtils.java @@ -0,0 +1,541 @@ +/* +* Copyright 2003 Federal Chancellery Austria +* +* Licensed under the Apache License, Version 2.0 (the "License"); +* you may not use this file except in compliance with the License. +* You may obtain a copy of the License at +* +* http://www.apache.org/licenses/LICENSE-2.0 +* +* Unless required by applicable law or agreed to in writing, software +* distributed under the License is distributed on an "AS IS" BASIS, +* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +* See the License for the specific language governing permissions and +* limitations under the License. +*/ +package at.gv.egovernment.moa.util; + +import java.util.List; +import java.util.Map; + +import org.w3c.dom.Attr; +import org.w3c.dom.Element; +import org.w3c.dom.Node; +import org.w3c.dom.NodeList; +import org.w3c.dom.traversal.NodeIterator; + +import org.jaxen.JaxenException; +import org.jaxen.NamespaceContext; +import org.jaxen.SimpleNamespaceContext; +import org.jaxen.dom.DOMXPath; +import org.jaxen.dom.DocumentNavigator; + +/** + * Utility methods to evaluate XPath expressions on DOM nodes. + * + * @author Patrick Peck + * @version $Id$ + */ +public class XPathUtils { + + /** + * The XPath expression selecting all nodes under a given root (including the + * root node itself). + */ + public static final String ALL_NODES_XPATH = + "(.//. | .//@* | .//namespace::*)"; + + /** The <code>DocumentNavigator</code> to use for navigating the document. */ + private static DocumentNavigator documentNavigator = + DocumentNavigator.getInstance(); + /** The default namespace prefix to namespace URI mappings. */ + private static NamespaceContext NS_CONTEXT; + + static { + SimpleNamespaceContext ctx = new SimpleNamespaceContext(); + ctx.addNamespace(Constants.MOA_PREFIX, Constants.MOA_NS_URI); + ctx.addNamespace(Constants.MOA_CONFIG_PREFIX, Constants.MOA_CONFIG_NS_URI); + ctx.addNamespace(Constants.MOA_ID_CONFIG_PREFIX, Constants.MOA_ID_CONFIG_NS_URI); + ctx.addNamespace(Constants.SL10_PREFIX, Constants.SL10_NS_URI); + ctx.addNamespace(Constants.SL11_PREFIX, Constants.SL11_NS_URI); + ctx.addNamespace(Constants.SL12_PREFIX, Constants.SL12_NS_URI); + ctx.addNamespace(Constants.ECDSA_PREFIX, Constants.ECDSA_NS_URI); + ctx.addNamespace(Constants.PD_PREFIX, Constants.PD_NS_URI); + ctx.addNamespace(Constants.SAML_PREFIX, Constants.SAML_NS_URI); + ctx.addNamespace(Constants.SAMLP_PREFIX, Constants.SAMLP_NS_URI); + ctx.addNamespace(Constants.DSIG_PREFIX, Constants.DSIG_NS_URI); + ctx.addNamespace(Constants.XSLT_PREFIX, Constants.XSLT_NS_URI); + ctx.addNamespace(Constants.XSI_PREFIX, Constants.XSI_NS_URI); + ctx.addNamespace(Constants.DSIG_FILTER2_PREFIX, Constants.DSIG_FILTER2_NS_URI); + ctx.addNamespace(Constants.DSIG_EC_PREFIX, Constants.DSIG_EC_NS_URI); + ctx.addNamespace(Constants.MD_PREFIX, Constants.MD_NS_URI); + ctx.addNamespace(Constants.MDP_PREFIX, Constants.MDP_NS_URI); + ctx.addNamespace(Constants.MVV_PREFIX, Constants.MVV_NS_URI); + ctx.addNamespace(Constants.STB_PREFIX, Constants.STB_NS_URI); + ctx.addNamespace(Constants.WRR_PREFIX, Constants.WRR_NS_URI); + NS_CONTEXT = ctx; + } + + /** + * Return a <code>NodeIterator</code> over the nodes matching the XPath + * expression. + * + * All namespace URIs and prefixes declared in the <code>Constants</code> + * interface are used for resolving namespaces. + * + * @param contextNode The root node from which to evaluate the XPath + * expression. + * @param exp The XPath expression to evaluate. + * @return An iterator over the resulting nodes. + * @throws XPathException An error occurred evaluating the XPath expression. + */ + public static NodeIterator selectNodeIterator(Node contextNode, String exp) + throws XPathException { + + return selectNodeIterator(contextNode, NS_CONTEXT, exp); + } + + /** + * Return a <code>NodeIterator</code> over the nodes matching the XPath + * expression. + * + * @param contextNode The root node from which to evaluate the XPath + * expression. + * @param namespaceElement An element from which to build the + * namespace mapping for evaluating the XPath expression + * @param exp The XPath expression to evaluate. + * @return An iterator over the resulting nodes. + * @throws XPathException An error occurred evaluating the XPath expression. + */ + public static NodeIterator selectNodeIterator( + Node contextNode, + Element namespaceElement, + String exp) + throws XPathException { + + try { + SimpleNamespaceContext ctx = new SimpleNamespaceContext(); + ctx.addElementNamespaces(documentNavigator, namespaceElement); + return selectNodeIterator(contextNode, ctx, exp); + } catch (JaxenException e) { + MessageProvider msg = MessageProvider.getInstance(); + String message = msg.getMessage("xpath.00", new Object[] { exp }); + throw new XPathException(message, e); + } + } + + /** + * Return a <code>NodeIterator</code> over the nodes matching the XPath + * expression. + * + * @param contextNode The root node from which to evaluate the XPath + * expression. + * @param namespaceMapping A namespace prefix to namespace URI mapping + * (<code>String</code> to <code>String</code>) for evaluating the XPath + * expression. + * @param exp The XPath expression to evaluate. + * @return An iterator over the resulting nodes. + * @throws XPathException An error occurred evaluating the XPath expression. + */ + public static NodeIterator selectNodeIterator( + Node contextNode, + Map namespaceMapping, + String exp) + throws XPathException { + + SimpleNamespaceContext ctx = new SimpleNamespaceContext(namespaceMapping); + + return selectNodeIterator(contextNode, ctx, exp); + } + + /** + * Return a <code>NodeIterator</code> over the nodes matching the XPath + * expression. + * + * @param contextNode The root node from which to evaluate the XPath + * expression. + * @param nsContext The <code>NamespaceContext</code> for resolving namespace + * prefixes to namespace URIs for evaluating the XPath expression. + * @param exp The XPath expression to evaluate. + * @return An iterator over the resulting nodes. + * @throws XPathException An error occurred evaluating the XPath expression. + */ + private static NodeIterator selectNodeIterator( + Node contextNode, + NamespaceContext nsContext, + String exp) + throws XPathException { + + try { + DOMXPath xpath = new DOMXPath(exp); + List nodes; + + xpath.setNamespaceContext(nsContext); + nodes = xpath.selectNodes(contextNode); + return new NodeIteratorAdapter(nodes.listIterator()); + } catch (JaxenException e) { + MessageProvider msg = MessageProvider.getInstance(); + String message = msg.getMessage("xpath.00", new Object[] { exp }); + throw new XPathException(message, e); + } + } + + /** + * Return a <code>NodeList</code> of all the nodes matching the XPath + * expression. + * + * All namespace URIs and prefixes declared in the <code>Constants</code> + * interface are used for resolving namespaces. + * + * @param contextNode The root node from which to evaluate the XPath + * expression. + * @param exp The XPath expression to evaluate. + * @return A <code>NodeList</code> containing the matching nodes. + * @throws XPathException An error occurred evaluating the XPath expression. + */ + public static NodeList selectNodeList(Node contextNode, String exp) + throws XPathException { + + return selectNodeList(contextNode, NS_CONTEXT, exp); + } + + /** + * Return a <code>NodeList</code> of all the nodes matching the XPath + * expression. + * + * @param contextNode The root node from which to evaluate the XPath + * expression. + * @param namespaceElement An element from which to build the + * namespace mapping for evaluating the XPath expression + * @param exp The XPath expression to evaluate. + * @return A <code>NodeList</code> containing the matching nodes. + * @throws XPathException An error occurred evaluating the XPath expression. + */ + public static NodeList selectNodeList( + Node contextNode, + Element namespaceElement, + String exp) + throws XPathException { + + try { + SimpleNamespaceContext ctx = new SimpleNamespaceContext(); + + ctx.addElementNamespaces(documentNavigator, namespaceElement); + return selectNodeList(contextNode, ctx, exp); + } catch (JaxenException e) { + MessageProvider msg = MessageProvider.getInstance(); + String message = msg.getMessage("xpath.00", new Object[] { exp }); + throw new XPathException(message, e); + } + } + + /** + * Return a <code>NodeList</code> of all the nodes matching the XPath + * expression. + * + * @param contextNode The root node from which to evaluate the XPath + * expression. + * @param namespaceMapping A namespace prefix to namespace URI mapping + * (<code>String</code> to <code>String</code>) for evaluating the XPath + * expression. + * @param exp The XPath expression to evaluate. + * @return A <code>NodeList</code> containing the matching nodes. + * @throws XPathException An error occurred evaluating the XPath expression. + */ + public static NodeList selectNodeList( + Node contextNode, + Map namespaceMapping, + String exp) + throws XPathException { + + SimpleNamespaceContext ctx = new SimpleNamespaceContext(namespaceMapping); + + return selectNodeList(contextNode, ctx, exp); + } + + /** + * Return a <code>NodeList</code> of all the nodes matching the XPath + * expression. + * + * @param contextNode The root node from which to evaluate the XPath + * expression. + * @param nsContext The <code>NamespaceContext</code> for resolving namespace + * prefixes to namespace URIs for evaluating the XPath expression. + * @param exp The XPath expression to evaluate. + * @return A <code>NodeList</code> containing the matching nodes. + * @throws XPathException An error occurred evaluating the XPath expression. + */ + private static NodeList selectNodeList( + Node contextNode, + NamespaceContext nsContext, + String exp) + throws XPathException { + + try { + DOMXPath xpath = new DOMXPath(exp); + List nodes; + + xpath.setNamespaceContext(nsContext); + nodes = xpath.selectNodes(contextNode); + return new NodeListAdapter(nodes); + } catch (JaxenException e) { + MessageProvider msg = MessageProvider.getInstance(); + String message = msg.getMessage("xpath.00", new Object[] { exp }); + throw new XPathException(message, e); + } + } + + /** + * Select the first node matching an XPath expression. + * + * All namespace URIs and prefixes declared in the <code>Constants</code> + * interface are used for resolving namespaces. + * + * @param contextNode The root node from which to evaluate the XPath + * expression. + * @param exp The XPath expression to evaluate. + * @return Node The first node matching the XPath expression, or + * <code>null</code>, if no node matched. + * @throws XPathException An error occurred evaluating the XPath expression. + */ + public static Node selectSingleNode(Node contextNode, String exp) + throws XPathException { + + return selectSingleNode(contextNode, NS_CONTEXT, exp); + } + + /** + * Select the first node matching an XPath expression. + * + * @param contextNode The root node from which to evaluate the XPath + * expression. + * @param namespaceElement An element from which to build the + * namespace mapping for evaluating the XPath expression + * @param exp The XPath expression to evaluate. + * @return Node The first node matching the XPath expression, or + * <code>null</code>, if no node matched. + * @throws XPathException An error occurred evaluating the XPath expression. + */ + public static Node selectSingleNode( + Node contextNode, + Element namespaceElement, + String exp) + throws XPathException { + + try { + SimpleNamespaceContext ctx = new SimpleNamespaceContext(); + ctx.addElementNamespaces(documentNavigator, namespaceElement); + + return selectSingleNode(contextNode, ctx, exp); + } catch (JaxenException e) { + MessageProvider msg = MessageProvider.getInstance(); + String message = msg.getMessage("xpath.00", new Object[] { exp }); + throw new XPathException(message, e); + } + } + + /** + * Select the first node matching an XPath expression. + * + * @param contextNode The root node from which to evaluate the XPath + * expression. + * @param namespaceMapping A namespace prefix to namespace URI mapping + * (<code>String</code> to <code>String</code>) for evaluating the XPath + * expression. + * @param exp The XPath expression to evaluate. + * @return Node The first node matching the XPath expression, or + * <code>null</code>, if no node matched. + * @throws XPathException An error occurred evaluating the XPath expression. + */ + public static Node selectSingleNode( + Node contextNode, + Map namespaceMapping, + String exp) + throws XPathException { + + SimpleNamespaceContext ctx = new SimpleNamespaceContext(namespaceMapping); + + return selectSingleNode(contextNode, ctx, exp); + } + + /** + * Select the first node matching an XPath expression. + * + * @param contextNode The root node from which to evaluate the XPath + * expression. + * @param nsContext The <code>NamespaceContext</code> for resolving namespace + * prefixes to namespace URIs for evaluating the XPath expression. + * @param exp The XPath expression to evaluate. + * @return Node The first node matching the XPath expression, or + * <code>null</code>, if no node matched. + * @throws XPathException An error occurred evaluating the XPath expression. + */ + private static Node selectSingleNode( + Node contextNode, + NamespaceContext nsContext, + String exp) + throws XPathException { + + try { + DOMXPath xpath = new DOMXPath(exp); + xpath.setNamespaceContext(nsContext); + return (Node) xpath.selectSingleNode(contextNode); + } catch (JaxenException e) { + MessageProvider msg = MessageProvider.getInstance(); + String message = msg.getMessage("xpath.00", new Object[] { exp }); + throw new XPathException(message, e); + } + } + + /** + * Return the value of a DOM element whose location is given by an XPath + * expression. + * + * @param root The root element from which to evaluate the XPath. + * @param xpath The XPath expression pointing to the element whose value + * to return. + * @param def The default value to return, if no element can be found using + * the given <code>xpath</code>. + * @return The element value, if it can be located using the + * <code>xpath</code>. Otherwise, <code>def</code> is returned. + */ + public static String getElementValue( + Element root, + String xpath, + String def) { + + Element elem = (Element) XPathUtils.selectSingleNode(root, xpath); + return elem != null ? DOMUtils.getText(elem) : def; + } + + /** + * Return the value of a DOM attribute whose location is given by an XPath + * expression. + * + * @param root The root element from which to evaluate the XPath. + * @param xpath The XPath expression pointing to the attribute whose value to + * return. + * @param def The default value to return, if no attribute can be found using + * the given <code>xpath</code>. + * @return The element value, if it can be located using the + * <code>xpath</code>. Otherwise, <code>def</code> is returned. + */ + public static String getAttributeValue( + Element root, + String xpath, + String def) { + + Attr attr = (Attr) XPathUtils.selectSingleNode(root, xpath); + return attr != null ? attr.getValue() : def; + } + + /** + * Returns the namespace prefix used within <code>XPathUtils</code> for referring to + * the namespace of the specified (Security Layer command) element. + * + * This namespace prefix can be used in various XPath expression evaluation methods + * within <code> XPathUtils</code> without explicitely binding it to the particular + * namespace. + * + * @param contextElement The (Security Layer command) element. + * + * @return the namespace prefix used within <code>XPathUtils</code> for referring to + * the namespace of the specified (Security Layer command) element. + * + * throws XpathException If the specified element has a namespace other than the ones + * known by this implementation as valid Security Layer namespaces (cf. + * @link Constants#SL10_NS_URI, @link Constants#SL11_NS_URI, @link Constants#SL12_NS_URI). + */ + public static String getSlPrefix (Element contextElement) throws XPathException + { + String sLNamespace = contextElement.getNamespaceURI(); + String sLPrefix = null; + + if (sLNamespace.equals(Constants.SL10_NS_URI)) + { + sLPrefix = Constants.SL10_PREFIX; + } + else if (sLNamespace.equals(Constants.SL12_NS_URI)) + { + sLPrefix = Constants.SL12_PREFIX; + } + else if (sLNamespace.equals(Constants.SL11_NS_URI)) + { + sLPrefix = Constants.SL11_PREFIX; + } + else + { + MessageProvider msg = MessageProvider.getInstance(); + String message = msg.getMessage("xpath.00", new Object[] { "Ungültiger Security Layer Namespace: \"" + sLNamespace + "\"."}); + throw new XPathException(message, null); + } + + return sLPrefix; + } + + + /** + * Return the SecurityLayer namespace prefix of the context element. + * If the context element is not the element that lies within the + * SecurityLayer namespace. The Securitylayer namespace is derived from + * the <code>xmlns:sl10</code>, <code>sl11</code> or <code>sl</code> + * attribute of the context element. + * + * The returned prefix is needed for evaluating XPATH expressions. + * + * @param contextElement The element to get a prefix for the Securitylayer namespace, + * that is used within the corresponding document. + * + * @return The string <code>sl10</code>, <code>sl11</code> or <code>sl</code>, + * depending on the SecurityLayer namespace of the contextElement. + * + * throws XPathException If no (vlalid) SecurityLayer namespace prefix or namespace + * is defined. + */ + public static String getSlPrefixFromNoRoot (Element contextElement) throws XPathException { + + String slPrefix = checkSLnsDeclaration(contextElement, Constants.SL10_PREFIX, Constants.SL10_NS_URI); + if (slPrefix == null) { + slPrefix = checkSLnsDeclaration(contextElement, Constants.SL11_PREFIX, Constants.SL11_NS_URI); + } + if (slPrefix == null) { + slPrefix = checkSLnsDeclaration(contextElement, Constants.SL12_PREFIX, Constants.SL12_NS_URI); + } + + return slPrefix; + + } + + /** + * Checks if the context element has an attribute <code>xmlns:slPrefix</code> and + * if the prefix of that attribute corresponds with a valid SecurityLayer namespace. + * + * @param contextElement The element to be checked. + * @param slPrefix The prefix which should be checked. Must be a valid SecurityLayer + * namespace prefix. + * @param slNameSpace The SecurityLayer namespace that corresponds to the specified prefix. + * + * @return The valid SecurityLayer prefix or <code>null</code> if this prefix is + * not used. + * @throws XPathException + */ + private static String checkSLnsDeclaration(Element contextElement, String slPrefix, String slNameSpace) + throws XPathException + { + String nsAtt = "xmlns:" + slPrefix; + String nameSpace = contextElement.getAttribute(nsAtt); + if (nameSpace == "") { + return null; + } else { + // check if namespace is correct + if (nameSpace.equals(slNameSpace)) { + return slPrefix; + } else { + MessageProvider msg = MessageProvider.getInstance(); + String message = msg.getMessage("xpath.00", new Object[] { "Ungültiger SecurityLayer Namespace: \"" + nameSpace + "\"."}); + throw new XPathException(message, null); + } + } + } + +} |