001 /*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements. See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership. The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the "License");
007 * you may not use this file except in compliance with the License.
008 * You may obtain a copy of the License at
009 *
010 * http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018
019 package org.apache.xalan.extensions;
020
021 import javax.xml.namespace.QName;
022 import javax.xml.xpath.XPathFunction;
023 import javax.xml.xpath.XPathFunctionResolver;
024 import org.apache.xalan.res.XSLMessages;
025 import org.apache.xalan.res.XSLTErrorResources;
026
027 /**
028 * A sample implementation of XPathFunctionResolver, with support for
029 * EXSLT extension functions and Java extension functions.
030 */
031 public class XPathFunctionResolverImpl implements XPathFunctionResolver
032 {
033 /**
034 * Resolve an extension function from the qualified name and arity.
035 */
036 public XPathFunction resolveFunction(QName qname, int arity)
037 {
038 if (qname == null)
039 throw new NullPointerException(
040 XSLMessages.createMessage(
041 XSLTErrorResources.ER_XPATH_RESOLVER_NULL_QNAME, null));
042
043 if (arity < 0)
044 throw new IllegalArgumentException(
045 XSLMessages.createMessage(
046 XSLTErrorResources.ER_XPATH_RESOLVER_NEGATIVE_ARITY, null));
047
048 String uri = qname.getNamespaceURI();
049 if (uri == null || uri.length() == 0)
050 return null;
051
052 String className = null;
053 String methodName = null;
054 if (uri.startsWith("http://exslt.org"))
055 {
056 className = getEXSLTClassName(uri);
057 methodName = qname.getLocalPart();
058 }
059 else if (!uri.equals(ExtensionNamespaceContext.JAVA_EXT_URI))
060 {
061 int lastSlash = className.lastIndexOf('/');
062 if (-1 != lastSlash)
063 className = className.substring(lastSlash + 1);
064 }
065
066 String localPart = qname.getLocalPart();
067 int lastDotIndex = localPart.lastIndexOf('.');
068 if (lastDotIndex > 0)
069 {
070 if (className != null)
071 className = className + "." + localPart.substring(0, lastDotIndex);
072 else
073 className = localPart.substring(0, lastDotIndex);
074
075 methodName = localPart.substring(lastDotIndex + 1);
076 }
077 else
078 methodName = localPart;
079
080 if(null == className || className.trim().length() == 0
081 || null == methodName || methodName.trim().length() == 0)
082 return null;
083
084 ExtensionHandler handler = null;
085 try
086 {
087 ExtensionHandler.getClassForName(className);
088 handler = new ExtensionHandlerJavaClass(uri, "javaclass", className);
089 }
090 catch (ClassNotFoundException e)
091 {
092 return null;
093 }
094 return new XPathFunctionImpl(handler, methodName);
095 }
096
097 /**
098 * Return the implementation class name of an EXSLT extension from
099 * a given namespace uri. The uri must starts with "http://exslt.org".
100 */
101 private String getEXSLTClassName(String uri)
102 {
103 if (uri.equals(ExtensionNamespaceContext.EXSLT_MATH_URI))
104 return "org.apache.xalan.lib.ExsltMath";
105 else if (uri.equals(ExtensionNamespaceContext.EXSLT_SET_URI))
106 return "org.apache.xalan.lib.ExsltSets";
107 else if (uri.equals(ExtensionNamespaceContext.EXSLT_STRING_URI))
108 return "org.apache.xalan.lib.ExsltStrings";
109 else if (uri.equals(ExtensionNamespaceContext.EXSLT_DATETIME_URI))
110 return "org.apache.xalan.lib.ExsltDatetime";
111 else if (uri.equals(ExtensionNamespaceContext.EXSLT_DYNAMIC_URI))
112 return "org.apache.xalan.lib.ExsltDynamic";
113 else if (uri.equals(ExtensionNamespaceContext.EXSLT_URI))
114 return "org.apache.xalan.lib.ExsltCommon";
115 else
116 return null;
117 }
118 }