001 /**
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements. See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License. You may obtain a copy of the License at
008 *
009 * http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017 package org.apache.camel.builder.xml;
018
019 import java.io.IOException;
020 import java.io.InputStream;
021 import javax.xml.transform.Source;
022 import javax.xml.transform.TransformerException;
023 import javax.xml.transform.URIResolver;
024 import javax.xml.transform.stream.StreamSource;
025
026 import org.apache.camel.spi.ClassResolver;
027 import org.apache.camel.util.FileUtil;
028 import org.apache.camel.util.ObjectHelper;
029 import org.apache.camel.util.ResourceHelper;
030 import org.slf4j.Logger;
031 import org.slf4j.LoggerFactory;
032
033 /**
034 * Camel specific {@link javax.xml.transform.URIResolver} which is capable of loading files
035 * from the classpath and file system.
036 * <p/>
037 * Use prefix <tt>classpath:</tt> or <tt>file:</tt> to denote either classpath or file system.
038 * If no prefix is provided then the prefix from the <tt>location</tt> parameter is used.
039 * If it neither has a prefix then <tt>classpath:</tt> is used.
040 * <p/>
041 * This implementation <b>cannot</b> load files over http.
042 *
043 * @version
044 */
045 public class XsltUriResolver implements URIResolver {
046
047 private static final Logger LOG = LoggerFactory.getLogger(XsltUriResolver.class);
048
049 private final ClassResolver resolver;
050 private final String location;
051 private final String baseScheme;
052
053 public XsltUriResolver(ClassResolver resolver, String location) {
054 this.resolver = resolver;
055 this.location = location;
056 if (ResourceHelper.hasScheme(location)) {
057 baseScheme = ResourceHelper.getScheme(location);
058 } else {
059 // default to use classpath
060 baseScheme = "classpath:";
061 }
062 }
063
064 public Source resolve(String href, String base) throws TransformerException {
065 // supports the empty href
066 if (ObjectHelper.isEmpty(href)) {
067 href = location;
068 }
069 if (ObjectHelper.isEmpty(href)) {
070 throw new TransformerException("include href is empty");
071 }
072
073 LOG.trace("Resolving URI with href: {} and base: {}", href, base);
074
075 String scheme = ResourceHelper.getScheme(href);
076 if (scheme != null) {
077 // need to compact paths for file/classpath as it can be relative paths using .. to go backwards
078 if ("file:".equals(scheme)) {
079 // compact path use file OS separator
080 href = FileUtil.compactPath(href);
081 } else if ("classpath:".equals(scheme)) {
082 // for classpath always use /
083 href = FileUtil.compactPath(href, '/');
084 }
085 LOG.debug("Resolving URI from {}: {}", scheme, href);
086
087 InputStream is;
088 try {
089 is = ResourceHelper.resolveMandatoryResourceAsInputStream(resolver, href);
090 } catch (IOException e) {
091 throw new TransformerException(e);
092 }
093 return new StreamSource(is);
094 }
095
096 // if href and location is the same, then its the initial resolve
097 if (href.equals(location)) {
098 String path = baseScheme + href;
099 return resolve(path, base);
100 }
101
102 // okay then its relative to the starting location from the XSLT component
103 String path = FileUtil.onlyPath(location);
104 if (ObjectHelper.isEmpty(path)) {
105 path = baseScheme + href;
106 return resolve(path, base);
107 } else {
108 if (ResourceHelper.hasScheme(path)) {
109 path = path + "/" + href;
110 } else {
111 path = baseScheme + path + "/" + href;
112 }
113 return resolve(path, base);
114 }
115 }
116
117 }