| /* |
| * 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. |
| */ |
| /* |
| * $Id: XPath.java 468655 2006-10-28 07:12:06Z minchau $ |
| */ |
| package org.apache.xpath; |
| |
| import java.io.Serializable; |
| |
| import javax.xml.transform.ErrorListener; |
| import javax.xml.transform.SourceLocator; |
| import javax.xml.transform.TransformerException; |
| |
| import org.apache.xalan.res.XSLMessages; |
| import org.apache.xml.dtm.DTM; |
| import org.apache.xml.utils.PrefixResolver; |
| import org.apache.xml.utils.SAXSourceLocator; |
| import org.apache.xpath.compiler.Compiler; |
| import org.apache.xpath.compiler.FunctionTable; |
| import org.apache.xpath.compiler.XPathParser; |
| import org.apache.xpath.functions.Function; |
| import org.apache.xpath.objects.XObject; |
| import org.apache.xpath.res.XPATHErrorResources; |
| |
| /** |
| * The XPath class wraps an expression object and provides general services |
| * for execution of that expression. |
| * @xsl.usage advanced |
| */ |
| public class XPath implements Serializable, ExpressionOwner |
| { |
| static final long serialVersionUID = 3976493477939110553L; |
| |
| /** The top of the expression tree. |
| * @serial */ |
| private Expression m_mainExp; |
| |
| /** |
| * The function table for xpath build-in functions |
| */ |
| private transient FunctionTable m_funcTable = null; |
| |
| /** |
| * initial the function table |
| */ |
| private void initFunctionTable(){ |
| m_funcTable = new FunctionTable(); |
| } |
| |
| /** |
| * Get the raw Expression object that this class wraps. |
| * |
| * |
| * @return the raw Expression object, which should not normally be null. |
| */ |
| public Expression getExpression() |
| { |
| return m_mainExp; |
| } |
| |
| /** |
| * This function is used to fixup variables from QNames to stack frame |
| * indexes at stylesheet build time. |
| * @param vars List of QNames that correspond to variables. This list |
| * should be searched backwards for the first qualified name that |
| * corresponds to the variable reference qname. The position of the |
| * QName in the vector from the start of the vector will be its position |
| * in the stack frame (but variables above the globalsTop value will need |
| * to be offset to the current stack frame). |
| */ |
| public void fixupVariables(java.util.Vector vars, int globalsSize) |
| { |
| m_mainExp.fixupVariables(vars, globalsSize); |
| } |
| |
| /** |
| * Set the raw expression object for this object. |
| * |
| * |
| * @param exp the raw Expression object, which should not normally be null. |
| */ |
| public void setExpression(Expression exp) |
| { |
| if(null != m_mainExp) |
| exp.exprSetParent(m_mainExp.exprGetParent()); // a bit bogus |
| m_mainExp = exp; |
| } |
| |
| /** |
| * Get the SourceLocator on the expression object. |
| * |
| * |
| * @return the SourceLocator on the expression object, which may be null. |
| */ |
| public SourceLocator getLocator() |
| { |
| return m_mainExp; |
| } |
| |
| // /** |
| // * Set the SourceLocator on the expression object. |
| // * |
| // * |
| // * @param l the SourceLocator on the expression object, which may be null. |
| // */ |
| // public void setLocator(SourceLocator l) |
| // { |
| // // Note potential hazards -- l may not be serializable, or may be changed |
| // // after being assigned here. |
| // m_mainExp.setSourceLocator(l); |
| // } |
| |
| /** The pattern string, mainly kept around for diagnostic purposes. |
| * @serial */ |
| String m_patternString; |
| |
| /** |
| * Return the XPath string associated with this object. |
| * |
| * |
| * @return the XPath string associated with this object. |
| */ |
| public String getPatternString() |
| { |
| return m_patternString; |
| } |
| |
| /** Represents a select type expression. */ |
| public static final int SELECT = 0; |
| |
| /** Represents a match type expression. */ |
| public static final int MATCH = 1; |
| |
| /** |
| * Construct an XPath object. |
| * |
| * (Needs review -sc) This method initializes an XPathParser/ |
| * Compiler and compiles the expression. |
| * @param exprString The XPath expression. |
| * @param locator The location of the expression, may be null. |
| * @param prefixResolver A prefix resolver to use to resolve prefixes to |
| * namespace URIs. |
| * @param type one of {@link #SELECT} or {@link #MATCH}. |
| * @param errorListener The error listener, or null if default should be used. |
| * |
| * @throws javax.xml.transform.TransformerException if syntax or other error. |
| */ |
| public XPath( |
| String exprString, SourceLocator locator, PrefixResolver prefixResolver, int type, |
| ErrorListener errorListener) |
| throws javax.xml.transform.TransformerException |
| { |
| initFunctionTable(); |
| if(null == errorListener) |
| errorListener = new org.apache.xml.utils.DefaultErrorHandler(); |
| |
| m_patternString = exprString; |
| |
| XPathParser parser = new XPathParser(errorListener, locator); |
| Compiler compiler = new Compiler(errorListener, locator, m_funcTable); |
| |
| if (SELECT == type) |
| parser.initXPath(compiler, exprString, prefixResolver); |
| else if (MATCH == type) |
| parser.initMatchPattern(compiler, exprString, prefixResolver); |
| else |
| throw new RuntimeException(XSLMessages.createXPATHMessage(XPATHErrorResources.ER_CANNOT_DEAL_XPATH_TYPE, new Object[]{Integer.toString(type)})); //"Can not deal with XPath type: " + type); |
| |
| // System.out.println("----------------"); |
| Expression expr = compiler.compile(0); |
| |
| // System.out.println("expr: "+expr); |
| this.setExpression(expr); |
| |
| if((null != locator) && locator instanceof ExpressionNode) |
| { |
| expr.exprSetParent((ExpressionNode)locator); |
| } |
| |
| } |
| |
| /** |
| * Construct an XPath object. |
| * |
| * (Needs review -sc) This method initializes an XPathParser/ |
| * Compiler and compiles the expression. |
| * @param exprString The XPath expression. |
| * @param locator The location of the expression, may be null. |
| * @param prefixResolver A prefix resolver to use to resolve prefixes to |
| * namespace URIs. |
| * @param type one of {@link #SELECT} or {@link #MATCH}. |
| * @param errorListener The error listener, or null if default should be used. |
| * |
| * @throws javax.xml.transform.TransformerException if syntax or other error. |
| */ |
| public XPath( |
| String exprString, SourceLocator locator, |
| PrefixResolver prefixResolver, int type, |
| ErrorListener errorListener, FunctionTable aTable) |
| throws javax.xml.transform.TransformerException |
| { |
| m_funcTable = aTable; |
| if(null == errorListener) |
| errorListener = new org.apache.xml.utils.DefaultErrorHandler(); |
| |
| m_patternString = exprString; |
| |
| XPathParser parser = new XPathParser(errorListener, locator); |
| Compiler compiler = new Compiler(errorListener, locator, m_funcTable); |
| |
| if (SELECT == type) |
| parser.initXPath(compiler, exprString, prefixResolver); |
| else if (MATCH == type) |
| parser.initMatchPattern(compiler, exprString, prefixResolver); |
| else |
| throw new RuntimeException(XSLMessages.createXPATHMessage( |
| XPATHErrorResources.ER_CANNOT_DEAL_XPATH_TYPE, |
| new Object[]{Integer.toString(type)})); |
| //"Can not deal with XPath type: " + type); |
| |
| // System.out.println("----------------"); |
| Expression expr = compiler.compile(0); |
| |
| // System.out.println("expr: "+expr); |
| this.setExpression(expr); |
| |
| if((null != locator) && locator instanceof ExpressionNode) |
| { |
| expr.exprSetParent((ExpressionNode)locator); |
| } |
| |
| } |
| |
| /** |
| * Construct an XPath object. |
| * |
| * (Needs review -sc) This method initializes an XPathParser/ |
| * Compiler and compiles the expression. |
| * @param exprString The XPath expression. |
| * @param locator The location of the expression, may be null. |
| * @param prefixResolver A prefix resolver to use to resolve prefixes to |
| * namespace URIs. |
| * @param type one of {@link #SELECT} or {@link #MATCH}. |
| * |
| * @throws javax.xml.transform.TransformerException if syntax or other error. |
| */ |
| public XPath( |
| String exprString, SourceLocator locator, PrefixResolver prefixResolver, int type) |
| throws javax.xml.transform.TransformerException |
| { |
| this(exprString, locator, prefixResolver, type, null); |
| } |
| |
| /** |
| * Construct an XPath object. |
| * |
| * @param expr The Expression object. |
| * |
| * @throws javax.xml.transform.TransformerException if syntax or other error. |
| */ |
| public XPath(Expression expr) |
| { |
| this.setExpression(expr); |
| initFunctionTable(); |
| } |
| |
| /** |
| * Given an expression and a context, evaluate the XPath |
| * and return the result. |
| * |
| * @param xctxt The execution context. |
| * @param contextNode The node that "." expresses. |
| * @param namespaceContext The context in which namespaces in the |
| * XPath are supposed to be expanded. |
| * |
| * @return The result of the XPath or null if callbacks are used. |
| * @throws TransformerException thrown if |
| * the error condition is severe enough to halt processing. |
| * |
| * @throws javax.xml.transform.TransformerException |
| * @xsl.usage experimental |
| */ |
| public XObject execute( |
| XPathContext xctxt, org.w3c.dom.Node contextNode, |
| PrefixResolver namespaceContext) |
| throws javax.xml.transform.TransformerException |
| { |
| return execute( |
| xctxt, xctxt.getDTMHandleFromNode(contextNode), |
| namespaceContext); |
| } |
| |
| |
| /** |
| * Given an expression and a context, evaluate the XPath |
| * and return the result. |
| * |
| * @param xctxt The execution context. |
| * @param contextNode The node that "." expresses. |
| * @param namespaceContext The context in which namespaces in the |
| * XPath are supposed to be expanded. |
| * |
| * @throws TransformerException thrown if the active ProblemListener decides |
| * the error condition is severe enough to halt processing. |
| * |
| * @throws javax.xml.transform.TransformerException |
| * @xsl.usage experimental |
| */ |
| public XObject execute( |
| XPathContext xctxt, int contextNode, PrefixResolver namespaceContext) |
| throws javax.xml.transform.TransformerException |
| { |
| |
| xctxt.pushNamespaceContext(namespaceContext); |
| |
| xctxt.pushCurrentNodeAndExpression(contextNode, contextNode); |
| |
| XObject xobj = null; |
| |
| try |
| { |
| xobj = m_mainExp.execute(xctxt); |
| } |
| catch (TransformerException te) |
| { |
| te.setLocator(this.getLocator()); |
| ErrorListener el = xctxt.getErrorListener(); |
| if(null != el) // defensive, should never happen. |
| { |
| el.error(te); |
| } |
| else |
| throw te; |
| } |
| catch (Exception e) |
| { |
| while (e instanceof org.apache.xml.utils.WrappedRuntimeException) |
| { |
| e = ((org.apache.xml.utils.WrappedRuntimeException) e).getException(); |
| } |
| // e.printStackTrace(); |
| |
| String msg = e.getMessage(); |
| |
| if (msg == null || msg.length() == 0) { |
| msg = XSLMessages.createXPATHMessage( |
| XPATHErrorResources.ER_XPATH_ERROR, null); |
| |
| } |
| TransformerException te = new TransformerException(msg, |
| getLocator(), e); |
| ErrorListener el = xctxt.getErrorListener(); |
| // te.printStackTrace(); |
| if(null != el) // defensive, should never happen. |
| { |
| el.fatalError(te); |
| } |
| else |
| throw te; |
| } |
| finally |
| { |
| xctxt.popNamespaceContext(); |
| |
| xctxt.popCurrentNodeAndExpression(); |
| } |
| |
| return xobj; |
| } |
| |
| /** |
| * Given an expression and a context, evaluate the XPath |
| * and return the result. |
| * |
| * @param xctxt The execution context. |
| * @param contextNode The node that "." expresses. |
| * @param namespaceContext The context in which namespaces in the |
| * XPath are supposed to be expanded. |
| * |
| * @throws TransformerException thrown if the active ProblemListener decides |
| * the error condition is severe enough to halt processing. |
| * |
| * @throws javax.xml.transform.TransformerException |
| * @xsl.usage experimental |
| */ |
| public boolean bool( |
| XPathContext xctxt, int contextNode, PrefixResolver namespaceContext) |
| throws javax.xml.transform.TransformerException |
| { |
| |
| xctxt.pushNamespaceContext(namespaceContext); |
| |
| xctxt.pushCurrentNodeAndExpression(contextNode, contextNode); |
| |
| try |
| { |
| return m_mainExp.bool(xctxt); |
| } |
| catch (TransformerException te) |
| { |
| te.setLocator(this.getLocator()); |
| ErrorListener el = xctxt.getErrorListener(); |
| if(null != el) // defensive, should never happen. |
| { |
| el.error(te); |
| } |
| else |
| throw te; |
| } |
| catch (Exception e) |
| { |
| while (e instanceof org.apache.xml.utils.WrappedRuntimeException) |
| { |
| e = ((org.apache.xml.utils.WrappedRuntimeException) e).getException(); |
| } |
| // e.printStackTrace(); |
| |
| String msg = e.getMessage(); |
| |
| if (msg == null || msg.length() == 0) { |
| msg = XSLMessages.createXPATHMessage( |
| XPATHErrorResources.ER_XPATH_ERROR, null); |
| |
| } |
| |
| TransformerException te = new TransformerException(msg, |
| getLocator(), e); |
| ErrorListener el = xctxt.getErrorListener(); |
| // te.printStackTrace(); |
| if(null != el) // defensive, should never happen. |
| { |
| el.fatalError(te); |
| } |
| else |
| throw te; |
| } |
| finally |
| { |
| xctxt.popNamespaceContext(); |
| |
| xctxt.popCurrentNodeAndExpression(); |
| } |
| |
| return false; |
| } |
| |
| /** Set to true to get diagnostic messages about the result of |
| * match pattern testing. */ |
| private static final boolean DEBUG_MATCHES = false; |
| |
| /** |
| * Get the match score of the given node. |
| * |
| * @param xctxt XPath runtime context. |
| * @param context The current source tree context node. |
| * |
| * @return score, one of {@link #MATCH_SCORE_NODETEST}, |
| * {@link #MATCH_SCORE_NONE}, {@link #MATCH_SCORE_OTHER}, |
| * or {@link #MATCH_SCORE_QNAME}. |
| * |
| * @throws javax.xml.transform.TransformerException |
| */ |
| public double getMatchScore(XPathContext xctxt, int context) |
| throws javax.xml.transform.TransformerException |
| { |
| |
| xctxt.pushCurrentNode(context); |
| xctxt.pushCurrentExpressionNode(context); |
| |
| try |
| { |
| XObject score = m_mainExp.execute(xctxt); |
| |
| if (DEBUG_MATCHES) |
| { |
| DTM dtm = xctxt.getDTM(context); |
| System.out.println("score: " + score.num() + " for " |
| + dtm.getNodeName(context) + " for xpath " |
| + this.getPatternString()); |
| } |
| |
| return score.num(); |
| } |
| finally |
| { |
| xctxt.popCurrentNode(); |
| xctxt.popCurrentExpressionNode(); |
| } |
| |
| // return XPath.MATCH_SCORE_NONE; |
| } |
| |
| |
| /** |
| * Warn the user of an problem. |
| * |
| * @param xctxt The XPath runtime context. |
| * @param sourceNode Not used. |
| * @param msg An error msgkey that corresponds to one of the constants found |
| * in {@link org.apache.xpath.res.XPATHErrorResources}, which is |
| * a key for a format string. |
| * @param args An array of arguments represented in the format string, which |
| * may be null. |
| * |
| * @throws TransformerException if the current ErrorListoner determines to |
| * throw an exception. |
| */ |
| public void warn( |
| XPathContext xctxt, int sourceNode, String msg, Object[] args) |
| throws javax.xml.transform.TransformerException |
| { |
| |
| String fmsg = XSLMessages.createXPATHWarning(msg, args); |
| ErrorListener ehandler = xctxt.getErrorListener(); |
| |
| if (null != ehandler) |
| { |
| |
| // TO DO: Need to get stylesheet Locator from here. |
| ehandler.warning(new TransformerException(fmsg, (SAXSourceLocator)xctxt.getSAXLocator())); |
| } |
| } |
| |
| /** |
| * Tell the user of an assertion error, and probably throw an |
| * exception. |
| * |
| * @param b If false, a runtime exception will be thrown. |
| * @param msg The assertion message, which should be informative. |
| * |
| * @throws RuntimeException if the b argument is false. |
| */ |
| public void assertion(boolean b, String msg) |
| { |
| |
| if (!b) |
| { |
| String fMsg = XSLMessages.createXPATHMessage( |
| XPATHErrorResources.ER_INCORRECT_PROGRAMMER_ASSERTION, |
| new Object[]{ msg }); |
| |
| throw new RuntimeException(fMsg); |
| } |
| } |
| |
| /** |
| * Tell the user of an error, and probably throw an |
| * exception. |
| * |
| * @param xctxt The XPath runtime context. |
| * @param sourceNode Not used. |
| * @param msg An error msgkey that corresponds to one of the constants found |
| * in {@link org.apache.xpath.res.XPATHErrorResources}, which is |
| * a key for a format string. |
| * @param args An array of arguments represented in the format string, which |
| * may be null. |
| * |
| * @throws TransformerException if the current ErrorListoner determines to |
| * throw an exception. |
| */ |
| public void error( |
| XPathContext xctxt, int sourceNode, String msg, Object[] args) |
| throws javax.xml.transform.TransformerException |
| { |
| |
| String fmsg = XSLMessages.createXPATHMessage(msg, args); |
| ErrorListener ehandler = xctxt.getErrorListener(); |
| |
| if (null != ehandler) |
| { |
| ehandler.fatalError(new TransformerException(fmsg, |
| (SAXSourceLocator)xctxt.getSAXLocator())); |
| } |
| else |
| { |
| SourceLocator slocator = xctxt.getSAXLocator(); |
| System.out.println(fmsg + "; file " + slocator.getSystemId() |
| + "; line " + slocator.getLineNumber() + "; column " |
| + slocator.getColumnNumber()); |
| } |
| } |
| |
| /** |
| * This will traverse the heararchy, calling the visitor for |
| * each member. If the called visitor method returns |
| * false, the subtree should not be called. |
| * |
| * @param owner The owner of the visitor, where that path may be |
| * rewritten if needed. |
| * @param visitor The visitor whose appropriate method will be called. |
| */ |
| public void callVisitors(ExpressionOwner owner, XPathVisitor visitor) |
| { |
| m_mainExp.callVisitors(this, visitor); |
| } |
| |
| /** |
| * The match score if no match is made. |
| * @xsl.usage advanced |
| */ |
| public static final double MATCH_SCORE_NONE = Double.NEGATIVE_INFINITY; |
| |
| /** |
| * The match score if the pattern has the form |
| * of a QName optionally preceded by an @ character. |
| * @xsl.usage advanced |
| */ |
| public static final double MATCH_SCORE_QNAME = 0.0; |
| |
| /** |
| * The match score if the pattern pattern has the form NCName:*. |
| * @xsl.usage advanced |
| */ |
| public static final double MATCH_SCORE_NSWILD = -0.25; |
| |
| /** |
| * The match score if the pattern consists of just a NodeTest. |
| * @xsl.usage advanced |
| */ |
| public static final double MATCH_SCORE_NODETEST = -0.5; |
| |
| /** |
| * The match score if the pattern consists of something |
| * other than just a NodeTest or just a qname. |
| * @xsl.usage advanced |
| */ |
| public static final double MATCH_SCORE_OTHER = 0.5; |
| } |
