Java tutorial
/* * 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.ode.bpel.elang.xpath20.runtime; import java.util.ArrayList; import java.util.Calendar; import java.util.Collections; import java.util.Date; import java.util.List; import java.util.Map; import javax.xml.namespace.QName; import javax.xml.transform.TransformerFactory; import javax.xml.xpath.XPath; import javax.xml.xpath.XPathConstants; import javax.xml.xpath.XPathExpression; import javax.xml.xpath.XPathExpressionException; import javax.xml.xpath.XPathFactory; import net.sf.saxon.Configuration; import net.sf.saxon.trans.XPathException; import net.sf.saxon.value.DurationValue; import net.sf.saxon.xpath.XPathFactoryImpl; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.apache.ode.bpel.common.FaultException; import org.apache.ode.bpel.elang.xpath10.o.OXPath10Expression; import org.apache.ode.bpel.elang.xpath20.compiler.WrappedResolverException; import org.apache.ode.bpel.elang.xpath20.o.OXPath20ExpressionBPEL20; import org.apache.ode.bpel.explang.ConfigurationException; import org.apache.ode.bpel.explang.EvaluationContext; import org.apache.ode.bpel.explang.EvaluationException; import org.apache.ode.bpel.explang.ExpressionLanguageRuntime; import org.apache.ode.bpel.o.OExpression; import org.apache.ode.utils.DOMUtils; import org.apache.ode.utils.ISO8601DateParser; import org.apache.ode.utils.xsd.Duration; import org.apache.ode.utils.xsl.XslTransformHandler; import org.w3c.dom.Document; import org.w3c.dom.Element; import org.w3c.dom.Node; import org.w3c.dom.NodeList; import org.w3c.dom.Text; /** * XPath 2.0 Expression Language run-time subsytem. * Saxon implementation. */ public class XPath20ExpressionRuntime implements ExpressionLanguageRuntime { static final short NODE_TYPE = 1; static final short NODESET_TYPE = 2; static final short STRING_TYPE = 3; static final short BOOLEAN_TYPE = 4; static final short NUMBER_TYPE = 5; /** Class-level logger. */ private static final Log __log = LogFactory.getLog(XPath20ExpressionRuntime.class); private final XPathFactory _xpf = new XPathFactoryImpl(); public XPath20ExpressionRuntime() { } public void initialize(Map properties) throws ConfigurationException { TransformerFactory trsf = new net.sf.saxon.TransformerFactoryImpl(); XslTransformHandler.getInstance().setTransformerFactory(trsf); } /** * @see org.apache.ode.bpel.explang.ExpressionLanguageRuntime#evaluateAsString(org.apache.ode.bpel.o.OExpression, org.apache.ode.bpel.explang.EvaluationContext) */ public String evaluateAsString(OExpression cexp, EvaluationContext ctx) throws FaultException, EvaluationException { return (String) evaluate(cexp, ctx, XPathConstants.STRING); } /** * @see org.apache.ode.bpel.explang.ExpressionLanguageRuntime#evaluateAsBoolean(org.apache.ode.bpel.o.OExpression, org.apache.ode.bpel.explang.EvaluationContext) */ public boolean evaluateAsBoolean(OExpression cexp, EvaluationContext ctx) throws FaultException, EvaluationException { return (Boolean) evaluate(cexp, ctx, XPathConstants.BOOLEAN); } public Number evaluateAsNumber(OExpression cexp, EvaluationContext ctx) throws FaultException, EvaluationException { return (Number) evaluate(cexp, ctx, XPathConstants.NUMBER); } /** * @see org.apache.ode.bpel.explang.ExpressionLanguageRuntime#evaluate(org.apache.ode.bpel.o.OExpression, org.apache.ode.bpel.explang.EvaluationContext) */ @SuppressWarnings("unchecked") public List evaluate(OExpression cexp, EvaluationContext ctx) throws FaultException, EvaluationException { List result; Object someRes = null; try { someRes = evaluate(cexp, ctx, XPathConstants.NODESET); } catch (Exception e) { someRes = evaluate(cexp, ctx, XPathConstants.STRING); } if (someRes instanceof List) { result = (List) someRes; if (__log.isDebugEnabled()) { __log.debug("Returned list of size " + result.size()); } if ((result.size() == 1) && !(result.get(0) instanceof Node)) { // Dealing with a Java class Object simpleType = result.get(0); // Dates get a separate treatment as we don't want to call toString on them String textVal; if (simpleType instanceof Date) { textVal = ISO8601DateParser.format((Date) simpleType); } else if (simpleType instanceof DurationValue) { textVal = ((DurationValue) simpleType).getStringValue(); } else { textVal = simpleType.toString(); } // Wrapping in a document Document document = DOMUtils.newDocument(); // Giving our node a parent just in case it's an LValue expression Element wrapper = document.createElement("wrapper"); Text text = document.createTextNode(textVal); wrapper.appendChild(text); document.appendChild(wrapper); result = Collections.singletonList(text); } } else if (someRes instanceof NodeList) { NodeList retVal = (NodeList) someRes; if (__log.isDebugEnabled()) { __log.debug("Returned node list of size " + retVal.getLength()); } result = new ArrayList(retVal.getLength()); for (int m = 0; m < retVal.getLength(); ++m) { Node val = retVal.item(m); if (val.getNodeType() == Node.DOCUMENT_NODE) { val = ((Document) val).getDocumentElement(); } result.add(val); } } else if (someRes instanceof String) { // Wrapping in a document Document document = DOMUtils.newDocument(); Element wrapper = document.createElement("wrapper"); Text text = document.createTextNode((String) someRes); wrapper.appendChild(text); document.appendChild(wrapper); result = Collections.singletonList(text); } else { result = null; } return result; } public Node evaluateNode(OExpression cexp, EvaluationContext ctx) throws FaultException, EvaluationException { List retVal = evaluate(cexp, ctx); if (retVal.size() == 0 || retVal.size() > 1) { StringBuffer msg = new StringBuffer( (retVal.size() == 0) ? "No results for expression: '" : "Multiple results for expression: '"); if (cexp instanceof OXPath10Expression) { msg.append(((OXPath10Expression) cexp).xpath); } else { msg.append(cexp.toString()); } msg.append('\''); if (ctx.getRootNode() != null) { msg.append(" against '"); msg.append(DOMUtils.domToString(ctx.getRootNode())); msg.append('\''); } if (retVal.size() == 0) throw new FaultException(cexp.getOwner().constants.qnSelectionFailure, msg.toString(), new Throwable("ignoreMissingFromData")); if (retVal.size() > 1) throw new FaultException(cexp.getOwner().constants.qnSelectionFailure, msg.toString()); } return (Node) retVal.get(0); } public Calendar evaluateAsDate(OExpression cexp, EvaluationContext context) throws FaultException, EvaluationException { List literal = DOMUtils.toList(evaluate(cexp, context)); if (literal.size() == 0) throw new FaultException(cexp.getOwner().constants.qnSelectionFailure, "No results for expression: " + cexp); if (literal.size() > 1) throw new FaultException(cexp.getOwner().constants.qnSelectionFailure, "Multiple results for expression: " + cexp); Object date = literal.get(0); if (date instanceof Calendar) return (Calendar) date; if (date instanceof Date) { Calendar cal = Calendar.getInstance(); cal.setTime((Date) date); return cal; } if (date instanceof Element) date = ((Element) date).getTextContent(); if (date instanceof Text) date = ((Text) date).getTextContent(); try { return ISO8601DateParser.parseCal(date.toString()); } catch (Exception ex) { String errmsg = "Invalid date: " + literal; __log.error(errmsg, ex); throw new FaultException(cexp.getOwner().constants.qnInvalidExpressionValue, errmsg); } } public Duration evaluateAsDuration(OExpression cexp, EvaluationContext context) throws FaultException, EvaluationException { String literal = this.evaluateAsString(cexp, context); try { return new Duration(literal); } catch (Exception ex) { String errmsg = "Invalid duration: " + literal; __log.error(errmsg, ex); throw new FaultException(cexp.getOwner().constants.qnInvalidExpressionValue, errmsg); } } private Object evaluate(OExpression cexp, EvaluationContext ctx, QName type) throws FaultException, EvaluationException { try { OXPath20ExpressionBPEL20 oxpath20 = ((OXPath20ExpressionBPEL20) cexp); JaxpFunctionResolver funcResolver = new JaxpFunctionResolver(ctx, oxpath20); JaxpVariableResolver varResolver = new JaxpVariableResolver(ctx, oxpath20, ((XPathFactoryImpl) _xpf).getConfiguration()); XPath xpe = _xpf.newXPath(); xpe.setXPathFunctionResolver(funcResolver); xpe.setXPathVariableResolver(varResolver); xpe.setNamespaceContext(oxpath20.namespaceCtx); String xpath = ((OXPath10Expression) cexp).xpath; XPathExpression expr = xpe.compile(xpath); Node contextNode = ctx.getRootNode(); if (contextNode == null) { contextNode = DOMUtils.newDocument(); } // Create step nodes in XPath in case it is incompletely instantiated if (oxpath20.insertMissingData) { XPath20ExpressionModifier modifier = new XPath20ExpressionModifier(oxpath20.namespaceCtx, ((XPathFactoryImpl) _xpf).getConfiguration().getNamePool()); Node temp = ctx.getRootNode(); if (temp.getLocalName().equals("message") && temp.getNamespaceURI() == null) { int startind = xpath.indexOf('.'); int endind = xpath.indexOf('/'); if (startind != -1) { String part = null; if (endind != -1) { part = xpath.substring(startind + 1, endind); } else { part = xpath.substring(startind + 1); } Element partElem = DOMUtils.findChildByName((Element) temp, new QName(null, part)); if (partElem != null && partElem.getFirstChild() != null) { temp = partElem.getFirstChild(); } } } modifier.insertMissingData(expr, temp); } Object evalResult = expr.evaluate(contextNode, type); if (evalResult != null && __log.isDebugEnabled()) { __log.debug("Expression " + cexp.toString() + " generated result " + evalResult + " - type=" + evalResult.getClass().getName()); if (ctx.getRootNode() != null) __log.debug("Was using context node " + DOMUtils.domToString(ctx.getRootNode())); } return evalResult; } catch (XPathExpressionException e) { // Extracting the real cause from all this wrapping isn't a simple task Throwable cause = e.getCause() != null ? e.getCause() : e; if (cause instanceof XPathException) { Throwable th = ((XPathException) cause).getException(); if (th != null) { cause = th; if (cause.getCause() != null) cause = cause.getCause(); } } throw new EvaluationException("Error while executing an XPath expression: " + cause.toString(), cause); } catch (WrappedResolverException wre) { __log.debug("Could not evaluate expression because of ", wre); throw (FaultException) wre.getCause(); } catch (Throwable t) { __log.debug("Could not evaluate expression because of ", t); throw new EvaluationException("Error while executing an XPath expression: ", t); } } }