opendaylight/netconf/netconf-netty-util/src/main/java/org/opendaylight/controller/netconf/nettyutil/handler/NetconfHelloMessageToXMLEncoder.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.Charsets;
  12 import com.google.common.base.Optional;
  13 import com.google.common.base.Preconditions;
  14 import io.netty.buffer.ByteBuf;
  15 import io.netty.channel.ChannelHandlerContext;
  16 import java.io.IOException;
  17 import javax.xml.transform.TransformerException;
  18 import org.opendaylight.controller.netconf.api.NetconfMessage;
  19 import org.opendaylight.controller.netconf.util.messages.NetconfHelloMessage;
  20 import org.opendaylight.controller.netconf.util.messages.NetconfHelloMessageAdditionalHeader;
  21
  22 /**
  23  * Customized NetconfMessageToXMLEncoder that serializes additional header with
  24  * session metadata along with
  25  * {@link org.opendaylight.controller.netconf.util.messages.NetconfHelloMessage}
  26  * . Used by netconf clients to send information about the user, ip address,
  27  * protocol etc.
  28  * <p/>
  29  * Hello message with header example:
  30  * <p/>
  31  *
  32  * <pre>
  33  * {@code
  34  * [tomas;10.0.0.0/10000;tcp;1000;1000;;/home/tomas;;]
  35  * <hello xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
  36  * <capabilities>
  37  * <capability>urn:ietf:params:netconf:base:1.0</capability>
  38  * </capabilities>
  39  * </hello>
  40  * }
  41  * </pre>
  42  */
  43 public final class NetconfHelloMessageToXMLEncoder extends NetconfMessageToXMLEncoder {
  44     @Override
  45     @VisibleForTesting
  46     public void encode(ChannelHandlerContext ctx, NetconfMessage msg, ByteBuf out) throws IOException, TransformerException {
  47         Preconditions.checkState(msg instanceof NetconfHelloMessage, "Netconf message of type %s expected, was %s",
  48                 NetconfHelloMessage.class, msg.getClass());
  49         Optional<NetconfHelloMessageAdditionalHeader> headerOptional = ((NetconfHelloMessage) msg)
  50                 .getAdditionalHeader();
  51
  52         // If additional header present, serialize it along with netconf hello message
  53         if (headerOptional.isPresent()) {
  54             out.writeBytes(headerOptional.get().toFormattedString().getBytes(Charsets.UTF_8));
  55         }
  56
  57         super.encode(ctx, msg, out);
  58     }
  59 }