1 /* 2 * reserved comment block 3 * DO NOT REMOVE OR ALTER! 4 */ 5 /** 6 * Licensed to the Apache Software Foundation (ASF) under one 7 * or more contributor license agreements. See the NOTICE file 8 * distributed with this work for additional information 9 * regarding copyright ownership. The ASF licenses this file 10 * to you under the Apache License, Version 2.0 (the 11 * "License"); you may not use this file except in compliance 12 * with the License. You may obtain a copy of the License at 13 * 14 * http://www.apache.org/licenses/LICENSE-2.0 15 * 16 * Unless required by applicable law or agreed to in writing, 17 * software distributed under the License is distributed on an 18 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 19 * KIND, either express or implied. See the License for the 20 * specific language governing permissions and limitations 21 * under the License. 22 */ 23 package com.sun.org.apache.xml.internal.security.utils; 24 25 26 /** 27 * A Factory to return an XPathAPI instance. If Xalan is available it returns XalanXPathAPI. If not, then 28 * it returns JDKXPathAPI. 29 */ 30 public abstract class XPathFactory { 31 32 private static boolean xalanInstalled; 33 34 static { 35 try { 36 Class<?> funcTableClass = 37 ClassLoaderUtils.loadClass("com.sun.org.apache.xpath.internal.compiler.FunctionTable", XPathFactory.class); 38 if (funcTableClass != null) { 39 xalanInstalled = true; 40 } 41 } catch (Exception e) { 42 //ignore 43 } 44 } 45 46 protected synchronized static boolean isXalanInstalled() { 47 return xalanInstalled; 48 } 49 50 /** 51 * Get a new XPathFactory instance 52 */ 53 public static XPathFactory newInstance() { 54 if (!isXalanInstalled()) { 55 return new JDKXPathFactory(); 56 } 57 // Xalan is available 58 if (XalanXPathAPI.isInstalled()) { 59 return new XalanXPathFactory(); 60 } 61 // Some problem was encountered in fixing up the Xalan FunctionTable so fall back to the 62 // JDK implementation 63 return new JDKXPathFactory(); 64 } 65 66 /** 67 * Get a new XPathAPI instance 68 */ 69 public abstract XPathAPI newXPathAPI(); 70 71 }