opendaylight/md-sal/sal-rest-connector/src/main/java/org/opendaylight/controller/sal/rest/impl/StructuredDataToXmlProvider.java

   1 /*
   2  * Copyright (c) 2014 Cisco Systems, Inc. and others.  All rights reserved.
   3  *
   4  * This program and the accompanying materials are made available under the
   5  * terms of the Eclipse Public License v1.0 which accompanies this distribution,
   6  * and is available at http://www.eclipse.org/legal/epl-v10.html
   7  */
   8 package org.opendaylight.controller.sal.rest.impl;
   9
  10 import java.io.IOException;
  11 import java.io.OutputStream;
  12 import java.lang.annotation.Annotation;
  13 import java.lang.reflect.Type;
  14
  15 import javax.ws.rs.Produces;
  16 import javax.ws.rs.WebApplicationException;
  17 import javax.ws.rs.core.MediaType;
  18 import javax.ws.rs.core.MultivaluedMap;
  19 import javax.ws.rs.core.Response;
  20 import javax.ws.rs.ext.MessageBodyWriter;
  21 import javax.ws.rs.ext.Provider;
  22 import javax.xml.transform.OutputKeys;
  23 import javax.xml.transform.Transformer;
  24 import javax.xml.transform.TransformerConfigurationException;
  25 import javax.xml.transform.TransformerException;
  26 import javax.xml.transform.TransformerFactory;
  27 import javax.xml.transform.dom.DOMSource;
  28 import javax.xml.transform.stream.StreamResult;
  29
  30 import org.opendaylight.controller.sal.rest.api.Draft02;
  31 import org.opendaylight.controller.sal.rest.api.RestconfService;
  32 import org.opendaylight.controller.sal.restconf.impl.RestconfDocumentedException;
  33 import org.opendaylight.controller.sal.restconf.impl.RestconfError.ErrorTag;
  34 import org.opendaylight.controller.sal.restconf.impl.RestconfError.ErrorType;
  35 import org.opendaylight.controller.sal.restconf.impl.StructuredData;
  36 import org.opendaylight.yangtools.yang.data.api.CompositeNode;
  37 import org.opendaylight.yangtools.yang.model.api.DataNodeContainer;
  38 import org.slf4j.Logger;
  39 import org.slf4j.LoggerFactory;
  40 import org.w3c.dom.Document;
  41
  42 @Provider
  43 @Produces({ Draft02.MediaTypes.API + RestconfService.XML, Draft02.MediaTypes.DATA + RestconfService.XML,
  44     Draft02.MediaTypes.OPERATION + RestconfService.XML, MediaType.APPLICATION_XML, MediaType.TEXT_XML })
  45 public enum StructuredDataToXmlProvider implements MessageBodyWriter<StructuredData> {
  46     INSTANCE;
  47
  48     private static final Logger LOG = LoggerFactory.getLogger(StructuredDataToXmlProvider.class);
  49     private static final TransformerFactory FACTORY = TransformerFactory.newInstance();
  50     private static final ThreadLocal<Transformer> TRANSFORMER = new ThreadLocal<Transformer>() {
  51         @Override
  52         protected Transformer initialValue() {
  53             final Transformer ret;
  54             try {
  55                 ret = FACTORY.newTransformer();
  56             } catch (TransformerConfigurationException e) {
  57                 LOG.error("Failed to instantiate XML transformer", e);
  58                 throw new IllegalStateException("XML encoding currently unavailable", e);
  59             }
  60
  61             ret.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "no");
  62             ret.setOutputProperty(OutputKeys.METHOD, "xml");
  63             ret.setOutputProperty(OutputKeys.INDENT, "yes");
  64             ret.setOutputProperty(OutputKeys.ENCODING, "UTF-8");
  65             ret.setOutputProperty("{http://xml.apache.org/xslt}indent-amount", "4");
  66
  67             return ret;
  68         }
  69     };
  70
  71     @Override
  72     public boolean isWriteable(final Class<?> type, final Type genericType, final Annotation[] annotations, final MediaType mediaType) {
  73         return type.equals( StructuredData.class );
  74     }
  75
  76     @Override
  77     public long getSize(final StructuredData t, final Class<?> type, final Type genericType, final Annotation[] annotations, final MediaType mediaType) {
  78         return -1;
  79     }
  80
  81     @Override
  82     public void writeTo(final StructuredData t, final Class<?> type, final Type genericType, final Annotation[] annotations,
  83             final MediaType mediaType, final MultivaluedMap<String, Object> httpHeaders, final OutputStream entityStream)
  84                     throws IOException, WebApplicationException {
  85         CompositeNode data = t.getData();
  86         if (data == null) {
  87             throw new RestconfDocumentedException(Response.Status.NOT_FOUND);
  88         }
  89
  90         final Transformer trans;
  91         try {
  92             trans = TRANSFORMER.get();
  93         } catch (RuntimeException e) {
  94             throw new RestconfDocumentedException(e.getMessage(), ErrorType.TRANSPORT,
  95                     ErrorTag.OPERATION_FAILED);
  96         }
  97
  98         // FIXME: BUG-1281: eliminate the intermediate Document
  99         final Document domTree = new XmlMapper().write(data, (DataNodeContainer) t.getSchema());
 100         try {
 101             trans.transform(new DOMSource(domTree), new StreamResult(entityStream));
 102         } catch (TransformerException e) {
 103             LOG.error("Error during translation of Document to OutputStream", e);
 104             throw new RestconfDocumentedException(e.getMessage(), ErrorType.TRANSPORT,
 105                     ErrorTag.OPERATION_FAILED);
 106         }
 107     }
 108
 109 }