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author | antelder <antelder@13f79535-47bb-0310-9956-ffa450edef68> | 2010-10-26 07:46:08 +0000 |
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committer | antelder <antelder@13f79535-47bb-0310-9956-ffa450edef68> | 2010-10-26 07:46:08 +0000 |
commit | 6865c59e74f19ed6057d03583944b47abd6e036e (patch) | |
tree | 3324c11c7ca4f5ca12f15619ce30e9824e198480 /sca-java-2.x/branches/2.0-Beta1/modules/assembly-xml/src/main/java/org/apache/tuscany/sca/policy/xml/PolicyXPathFunction.java | |
parent | 0d6d7922ed17cca55ec36ff2626d1080e76d6d13 (diff) |
Create branch for next release
git-svn-id: http://svn.us.apache.org/repos/asf/tuscany@1027394 13f79535-47bb-0310-9956-ffa450edef68
Diffstat (limited to '')
-rw-r--r-- | sca-java-2.x/branches/2.0-Beta1/modules/assembly-xml/src/main/java/org/apache/tuscany/sca/policy/xml/PolicyXPathFunction.java | 295 |
1 files changed, 295 insertions, 0 deletions
diff --git a/sca-java-2.x/branches/2.0-Beta1/modules/assembly-xml/src/main/java/org/apache/tuscany/sca/policy/xml/PolicyXPathFunction.java b/sca-java-2.x/branches/2.0-Beta1/modules/assembly-xml/src/main/java/org/apache/tuscany/sca/policy/xml/PolicyXPathFunction.java new file mode 100644 index 0000000000..8e2d7f9e60 --- /dev/null +++ b/sca-java-2.x/branches/2.0-Beta1/modules/assembly-xml/src/main/java/org/apache/tuscany/sca/policy/xml/PolicyXPathFunction.java @@ -0,0 +1,295 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you 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 org.apache.tuscany.sca.policy.xml; + +import java.util.ArrayList; +import java.util.Arrays; +import java.util.HashSet; +import java.util.List; +import java.util.Set; +import java.util.logging.Level; +import java.util.logging.Logger; +import java.util.regex.Matcher; +import java.util.regex.Pattern; + +import javax.xml.XMLConstants; +import javax.xml.namespace.NamespaceContext; +import javax.xml.namespace.QName; +import javax.xml.xpath.XPathFunction; +import javax.xml.xpath.XPathFunctionException; + +import org.w3c.dom.Document; +import org.w3c.dom.Node; +import org.w3c.dom.NodeList; + +/** + * The SCA-defined XPath function + */ +public class PolicyXPathFunction implements XPathFunction { + private static Logger logger = Logger.getLogger(PolicyXPathFunction.class.getName()); + + static final QName InterfaceRef = new QName(PolicyConstants.SCA11_NS, "InterfaceRef"); + static final QName OperationRef = new QName(PolicyConstants.SCA11_NS, "OperationRef"); + static final QName MessageRef = new QName(PolicyConstants.SCA11_NS, "MessageRef"); + static final QName IntentRefs = new QName(PolicyConstants.SCA11_NS, "IntentRefs"); + static final QName URIRef = new QName(PolicyConstants.SCA11_NS, "URIRef"); + + static final Set<QName> functions = + new HashSet<QName>(Arrays.asList(InterfaceRef, OperationRef, MessageRef, IntentRefs, URIRef)); + + private NamespaceContext namespaceContext; + private final QName functionName; + + public PolicyXPathFunction(NamespaceContext namespaceContext, QName functionName) { + super(); + this.namespaceContext = namespaceContext; + this.functionName = functionName; + } + + private Node getContextNode(List args) { + if (args.size() >= 2) { + NodeList nodeList = (NodeList)args.get(1); + if (nodeList.getLength() > 0) { + return nodeList.item(0); + } + } + return null; + } + + public Object evaluate(List args) throws XPathFunctionException { + if (logger.isLoggable(Level.FINE)) { + logger.fine(functionName + "(" + args + ")"); + } + + String arg = (String)args.get(0); + Node node = getContextNode(args); + /** + * If the xpath expression that contains the function does not select any nodes + * (eg IntentRefs('someIntent')), the context node passed in will be a Document. + * In this case we need to iterate over every Node in the Document and evaluate it. + * + * If the xpath expression does select nodes (eg //sca:component[IntentRefs('someIntent')]) + * then xpath will call evaluate for each node and we only need to return the result for that + * node. + */ + if ( node instanceof Document ) + return evaluateDocument(arg, (Document)node); + else + return evaluateNode(arg, node); + } + + public Object evaluateNode(String arg, Node node) { + if (InterfaceRef.equals(functionName)) { + return evaluateInterface(arg, node); + } else if (OperationRef.equals(functionName)) { + String[] params = arg.split("/"); + if (params.length != 2) { + throw new IllegalArgumentException("Invalid argument: " + arg); + } + String interfaceName = params[0]; + String operationName = params[1]; + return evaluateOperation(interfaceName, operationName, node); + } else if (MessageRef.equals(functionName)) { + String[] params = arg.split("/"); + if (params.length != 3) { + throw new IllegalArgumentException("Invalid argument: " + arg); + } + String interfaceName = params[0]; + String operationName = params[1]; + String messageName = params[2]; + return evaluateMessage(interfaceName, operationName, messageName, node); + } else if (URIRef.equals(functionName)) { + return evaluateURI(arg, node); + } else if (IntentRefs.equals(functionName)) { + String[] intents = arg.split("(\\s)+"); + return evaluateIntents(intents, node); + } else { + return Boolean.FALSE; + } + } + + private class NodeListImpl implements NodeList { + + private ArrayList<Node> list; + + public NodeListImpl() { + this.list = new ArrayList<Node>(); + } + public int getLength() { + return this.list.size(); + } + + public Node item(int index) { + return this.list.get(index); + } + public boolean add(Node node) { + return this.list.add(node); + + } + + } + private Object evaluateDocument(String arg, Document doc) { + NodeListImpl retList = new NodeListImpl(); + NodeList elements = doc.getElementsByTagName("*"); + for ( int i=0; i < elements.getLength(); i++) { + Object node = evaluateNode(arg, elements.item(i)); + if ( node != null ) + retList.add((Node)node); + } + return retList; + } + + private Boolean evaluateInterface(String interfaceName, Node node) { + return Boolean.FALSE; + } + + private Boolean evaluateOperation(String interfaceName, String operationName, Node node) { + return Boolean.FALSE; + } + + private Boolean evaluateMessage(String interfaceName, String operationName, String messageName, Node node) { + return Boolean.FALSE; + } + + private Boolean evaluateURI(String uri, Node node) { + return Boolean.FALSE; + } + + /** + * Evaluates a single node for the given intents. + * @param intents + * @param node + * @return + */ + private Object evaluateIntents(String[] intents, Node node) { + if ( node == null ) + return false; + + if ( node.getAttributes() != null ) { + for ( int i=0; i < node.getAttributes().getLength(); i++) { + Node attr = node.getAttributes().item(i); + + if ( "requires".equalsIgnoreCase(attr.getNodeName())) { + + for ( int j = 0; j < intents.length; j++ ) { + // Check negative intents + if ( intents[j].startsWith("!")) { + if ( matchIntent(intents[j].substring(1), attr, node.getNamespaceURI())) + return null; + } else if ( !matchIntent(intents[j], attr, node.getNamespaceURI())){ + return null; + } + } + return node; + } + + } + } + + return null; + } + + + + /** + * Determine whether the given intent is present in the "requires" attribute + * @param intent + * @param node + * @param namespaceURI + * @return + */ + private boolean matchIntent(String intent, Node node, String namespaceURI) { + String[] requires = node.getNodeValue().split("(\\s)+"); + QName intentName = getStringAsQName(intent); + + + for ( int i=0; i < requires.length; i++ ) { + QName nodeName = null; + int idx = requires[i].indexOf(':'); + + // No prefix specified + if ( idx == -1 ) { + nodeName = new QName(namespaceURI, requires[i]); + } else { + String prefix = requires[i].substring(0, idx); + String name = requires[i].substring(idx + 1); + String ns = node.lookupNamespaceURI(prefix); + nodeName = new QName(ns, name, prefix); + } + if ( intentName.equals(nodeName)) + return true; + } + return false; + } + + + private QName getStringAsQName(String intent) { + int idx = intent.indexOf(':'); + if (idx == -1) + return new QName(namespaceContext.getNamespaceURI(XMLConstants.DEFAULT_NS_PREFIX), intent); + + String prefix = intent.substring(0, idx); + intent = intent.substring(idx + 1); + + return new QName(namespaceContext.getNamespaceURI(prefix), intent, prefix); + + } + + + private static Pattern FUNCTION; + static { + String functionPattern = "(URIRef|InterfaceRef|OperationRef|MessageRef|IntentRefs)\\s*\\(([^\\)]*)\\)"; + FUNCTION = Pattern.compile(functionPattern); + } + + /** Adds the node as an argument to the XPath function. + * Required in order to have access to the NodeList within the function + */ + public static String normalize(String attachTo, String scaPrefix) { + // Get rid of any whitespace + attachTo = attachTo.trim(); + + Matcher matcher = FUNCTION.matcher(attachTo); + boolean result = matcher.find(); + if (result) { + StringBuffer sb = new StringBuffer(); + do { + String function = matcher.group(1); + String args = matcher.group(2); + if ( (matcher.start() == 0) || (attachTo.charAt( matcher.start() -1) != ':' )) { + function = scaPrefix + ":" + function; + } + String replacement = null; + if (args.trim().length() > 0) { + replacement = function + "(" + args + "," + "self::node())"; + } else { + replacement = function + "(self::node())"; + } + matcher.appendReplacement(sb, replacement); + result = matcher.find(); + } while (result); + + matcher.appendTail(sb); + return sb.toString(); + } + return attachTo; + } + +} |