opendaylight/netconf/netconf-netty-util/src/main/java/org/opendaylight/controller/netconf/nettyutil/handler/NetconfMessageToXMLEncoder.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.netconf.nettyutil.handler;
   9
  10 import com.google.common.annotations.VisibleForTesting;
  11 import com.google.common.base.Optional;
  12 import io.netty.buffer.ByteBuf;
  13 import io.netty.buffer.ByteBufOutputStream;
  14 import io.netty.channel.ChannelHandlerContext;
  15 import io.netty.handler.codec.MessageToByteEncoder;
  16 import java.io.BufferedWriter;
  17 import java.io.IOException;
  18 import java.io.OutputStream;
  19 import java.io.OutputStreamWriter;
  20 import javax.xml.transform.OutputKeys;
  21 import javax.xml.transform.Transformer;
  22 import javax.xml.transform.TransformerException;
  23 import javax.xml.transform.TransformerFactory;
  24 import javax.xml.transform.dom.DOMSource;
  25 import javax.xml.transform.stream.StreamResult;
  26 import org.opendaylight.controller.netconf.api.NetconfMessage;
  27 import org.slf4j.Logger;
  28 import org.slf4j.LoggerFactory;
  29 import org.w3c.dom.Comment;
  30
  31 public class NetconfMessageToXMLEncoder extends MessageToByteEncoder<NetconfMessage> {
  32     private static final Logger LOG = LoggerFactory.getLogger(NetconfMessageToXMLEncoder.class);
  33     private static final TransformerFactory FACTORY = TransformerFactory.newInstance();
  34
  35     private final Optional<String> clientId;
  36
  37     public NetconfMessageToXMLEncoder() {
  38         this(Optional.<String>absent());
  39     }
  40
  41     public NetconfMessageToXMLEncoder(Optional<String> clientId) {
  42         this.clientId = clientId;
  43     }
  44
  45     @Override
  46     @VisibleForTesting
  47     public void encode(ChannelHandlerContext ctx, NetconfMessage msg, ByteBuf out) throws IOException, TransformerException {
  48         LOG.trace("Sent to encode : {}", msg);
  49
  50         if (clientId.isPresent()) {
  51             Comment comment = msg.getDocument().createComment("clientId:" + clientId.get());
  52             msg.getDocument().appendChild(comment);
  53         }
  54
  55         try (OutputStream os = new ByteBufOutputStream(out)) {
  56             Transformer transformer = FACTORY.newTransformer();
  57             transformer.setOutputProperty(OutputKeys.INDENT, "yes");
  58             transformer.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "yes");
  59
  60             // Wrap OutputStreamWriter with BufferedWriter as suggested in javadoc for OutputStreamWriter
  61             StreamResult result = new StreamResult(new BufferedWriter(new OutputStreamWriter(os)));
  62             DOMSource source = new DOMSource(msg.getDocument());
  63             transformer.transform(source, result);
  64         }
  65     }
  66 }