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 io.netty.buffer.ByteBuf;
  11 import io.netty.channel.ChannelHandlerContext;
  12
  13 import java.io.IOException;
  14
  15 import javax.xml.transform.TransformerException;
  16
  17 import org.opendaylight.controller.netconf.api.NetconfMessage;
  18 import org.opendaylight.controller.netconf.util.messages.NetconfHelloMessage;
  19 import org.opendaylight.controller.netconf.util.messages.NetconfHelloMessageAdditionalHeader;
  20
  21 import com.google.common.annotations.VisibleForTesting;
  22 import com.google.common.base.Charsets;
  23 import com.google.common.base.Optional;
  24 import com.google.common.base.Preconditions;
  25
  26 /**
  27  * Customized NetconfMessageToXMLEncoder that serializes additional header with
  28  * session metadata along with
  29  * {@link org.opendaylight.controller.netconf.util.messages.NetconfHelloMessage}
  30  * . Used by netconf clients to send information about the user, ip address,
  31  * protocol etc.
  32  * <p/>
  33  * Hello message with header example:
  34  * <p/>
  35  *
  36  * <pre>
  37  * {@code
  38  * [tomas;10.0.0.0/10000;tcp;1000;1000;;/home/tomas;;]
  39  * <hello xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
  40  * <capabilities>
  41  * <capability>urn:ietf:params:netconf:base:1.0</capability>
  42  * </capabilities>
  43  * </hello>
  44  * }
  45  * </pre>
  46  */
  47 public final class NetconfHelloMessageToXMLEncoder extends NetconfMessageToXMLEncoder {
  48     @Override
  49     @VisibleForTesting
  50     public void encode(ChannelHandlerContext ctx, NetconfMessage msg, ByteBuf out) throws IOException, TransformerException {
  51         Preconditions.checkState(msg instanceof NetconfHelloMessage, "Netconf message of type %s expected, was %s",
  52                 NetconfHelloMessage.class, msg.getClass());
  53         Optional<NetconfHelloMessageAdditionalHeader> headerOptional = ((NetconfHelloMessage) msg)
  54                 .getAdditionalHeader();
  55
  56         // If additional header present, serialize it along with netconf hello
  57         // message
  58         if (headerOptional.isPresent()) {
  59             out.writeBytes(headerOptional.get().toFormattedString().getBytes(Charsets.UTF_8));
  60         }
  61
  62         super.encode(ctx, msg, out);
  63     }
  64 }