runtime/org.argeo.slc.server/src/main/java/org/argeo/slc/web/mvc/XsltMarshallerViewResolver.java

   1 /*
   2  * Copyright (C) 2010 Mathieu Baudier <mbaudier@argeo.org>
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  *         http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16
  17 package org.argeo.slc.web.mvc;
  18
  19 import java.io.IOException;
  20 import java.util.Map;
  21 import java.util.TreeMap;
  22
  23 import javax.xml.transform.Source;
  24 import javax.xml.transform.TransformerException;
  25 import javax.xml.transform.URIResolver;
  26 import javax.xml.transform.stream.StreamSource;
  27
  28 import org.apache.commons.logging.Log;
  29 import org.apache.commons.logging.LogFactory;
  30 import org.argeo.slc.SlcException;
  31 import org.springframework.core.io.Resource;
  32 import org.springframework.oxm.Marshaller;
  33 import org.springframework.web.servlet.view.AbstractUrlBasedView;
  34 import org.springframework.web.servlet.view.xslt.XsltViewResolver;
  35
  36 /**
  37  * Xslt View resolver implementing URI resolver as well.
  38  *
  39  * @see URIResolver
  40  * @see XsltViewResolver
  41  */
  42 public class XsltMarshallerViewResolver extends XsltViewResolver implements
  43                 URIResolver {
  44         private final static Log log = LogFactory
  45                         .getLog(XsltMarshallerViewResolver.class);
  46
  47         private Marshaller marshaller;
  48         private Map<String, Source> cacheUriResolver = new TreeMap<String, Source>();
  49
  50         public XsltMarshallerViewResolver() {
  51                 setUriResolver(this);
  52         }
  53
  54         @Override
  55         protected AbstractUrlBasedView buildView(String viewName) throws Exception {
  56                 AbstractUrlBasedView viewT = super.buildView(viewName);
  57                 XsltMarshallerView view = (XsltMarshallerView) viewT;
  58                 view.setMarshaller(marshaller);
  59                 return view;
  60         }
  61
  62         public void setMarshaller(Marshaller marshaller) {
  63                 this.marshaller = marshaller;
  64         }
  65
  66         public Source resolve(String href, String base) throws TransformerException {
  67                 if (log.isTraceEnabled())
  68                         log.trace("Resolve URI for href=" + href + " base=" + base);
  69
  70                 Source res = null;
  71                 if (isCache())
  72                         res = cacheUriResolver.get(href);
  73
  74                 if (res == null)
  75                         res = getStylesheetSource(href);
  76
  77                 if (res == null)
  78                         res = getStylesheetSource(getPrefix() + href);
  79
  80                 if (res == null)
  81                         throw new SlcException("Can't resolve URI for href=" + href
  82                                         + " base=" + base);
  83
  84                 if (isCache() && !cacheUriResolver.containsKey(href))
  85                         cacheUriResolver.put(href, res);
  86
  87                 return res;
  88         }
  89
  90         protected Source getStylesheetSource(String url) {
  91                 if (log.isDebugEnabled()) {
  92                         log.debug("Loading XSLT stylesheet from '" + url + "'");
  93                 }
  94                 try {
  95                         final Resource stylesheetResource = getApplicationContext()
  96                                         .getResource(url);
  97                         String systemId = url.substring(0, url.lastIndexOf('/') + 1);
  98                         return new StreamSource(stylesheetResource.getInputStream(),
  99                                         systemId);
 100                 } catch (IOException e) {
 101                         if (log.isTraceEnabled())
 102                                 log.trace("Cannot load stylesheet " + url, e);
 103                         return null;
 104                 }
 105         }
 106
 107 }