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 import javax.ws.rs.Produces;
  15 import javax.ws.rs.WebApplicationException;
  16 import javax.ws.rs.core.MediaType;
  17 import javax.ws.rs.core.MultivaluedMap;
  18 import javax.ws.rs.core.Response;
  19 import javax.ws.rs.ext.MessageBodyWriter;
  20 import javax.ws.rs.ext.Provider;
  21 import javax.xml.transform.OutputKeys;
  22 import javax.xml.transform.Transformer;
  23 import javax.xml.transform.TransformerConfigurationException;
  24 import javax.xml.transform.TransformerException;
  25 import javax.xml.transform.TransformerFactory;
  26 import javax.xml.transform.dom.DOMSource;
  27 import javax.xml.transform.stream.StreamResult;
  28 import org.opendaylight.controller.sal.rest.api.Draft02;
  29 import org.opendaylight.controller.sal.rest.api.RestconfService;
  30 import org.opendaylight.controller.sal.restconf.impl.RestconfDocumentedException;
  31 import org.opendaylight.controller.sal.restconf.impl.RestconfError.ErrorTag;
  32 import org.opendaylight.controller.sal.restconf.impl.RestconfError.ErrorType;
  33 import org.opendaylight.controller.sal.restconf.impl.StructuredData;
  34 import org.opendaylight.yangtools.yang.data.api.CompositeNode;
  35 import org.opendaylight.yangtools.yang.model.api.DataNodeContainer;
  36 import org.slf4j.Logger;
  37 import org.slf4j.LoggerFactory;
  38 import org.w3c.dom.Document;
  39
  40 @Provider
  41 @Produces({ Draft02.MediaTypes.API + RestconfService.XML, Draft02.MediaTypes.DATA + RestconfService.XML,
  42     Draft02.MediaTypes.OPERATION + RestconfService.XML, MediaType.APPLICATION_XML, MediaType.TEXT_XML })
  43 public enum StructuredDataToXmlProvider implements MessageBodyWriter<StructuredData> {
  44     INSTANCE;
  45
  46     private static final Logger LOG = LoggerFactory.getLogger(StructuredDataToXmlProvider.class);
  47     private static final TransformerFactory FACTORY = TransformerFactory.newInstance();
  48     private static final ThreadLocal<Transformer> TRANSFORMER = new ThreadLocal<Transformer>() {
  49         @Override
  50         protected Transformer initialValue() {
  51             final Transformer ret;
  52             try {
  53                 ret = FACTORY.newTransformer();
  54             } catch (TransformerConfigurationException e) {
  55                 LOG.error("Failed to instantiate XML transformer", e);
  56                 throw new IllegalStateException("XML encoding currently unavailable", e);
  57             }
  58
  59             ret.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "no");
  60             ret.setOutputProperty(OutputKeys.METHOD, "xml");
  61             ret.setOutputProperty(OutputKeys.INDENT, "yes");
  62             ret.setOutputProperty(OutputKeys.ENCODING, "UTF-8");
  63             ret.setOutputProperty("{http://xml.apache.org/xslt}indent-amount", "4");
  64
  65             return ret;
  66         }
  67     };
  68
  69     @Override
  70     public boolean isWriteable(final Class<?> type, final Type genericType, final Annotation[] annotations, final MediaType mediaType) {
  71         return type.equals(StructuredData.class);
  72     }
  73
  74     @Override
  75     public long getSize(final StructuredData t, final Class<?> type, final Type genericType, final Annotation[] annotations, final MediaType mediaType) {
  76         return -1;
  77     }
  78
  79     @Override
  80     public void writeTo(final StructuredData t, final Class<?> type, final Type genericType, final Annotation[] annotations,
  81             final MediaType mediaType, final MultivaluedMap<String, Object> httpHeaders, final OutputStream entityStream)
  82                     throws IOException, WebApplicationException {
  83         CompositeNode data = t.getData();
  84         if (data == null) {
  85             throw new RestconfDocumentedException(Response.Status.NOT_FOUND);
  86         }
  87
  88         final Transformer trans;
  89         try {
  90             trans = TRANSFORMER.get();
  91             if (t.isPrettyPrintMode()) {
  92                 trans.setOutputProperty(OutputKeys.INDENT, "yes");
  93             } else {
  94                 trans.setOutputProperty(OutputKeys.INDENT, "no");
  95             }
  96         } catch (RuntimeException e) {
  97             throw new RestconfDocumentedException(e.getMessage(), ErrorType.TRANSPORT,
  98                     ErrorTag.OPERATION_FAILED);
  99         }
 100
 101         // FIXME: BUG-1281: eliminate the intermediate Document
 102         final Document domTree = new XmlMapper().write(data, (DataNodeContainer) t.getSchema());
 103         try {
 104             trans.transform(new DOMSource(domTree), new StreamResult(entityStream));
 105         } catch (TransformerException e) {
 106             LOG.error("Error during translation of Document to OutputStream", e);
 107             throw new RestconfDocumentedException(e.getMessage(), ErrorType.TRANSPORT,
 108                     ErrorTag.OPERATION_FAILED);
 109         }
 110     }
 111
 112 }