Java tutorial
/* * Copyright (c) 2014 Cisco Systems, Inc. and others. All rights reserved. * * This program and the accompanying materials are made available under the * terms of the Eclipse Public License v1.0 which accompanies this distribution, * and is available at http://www.eclipse.org/legal/epl-v10.html */ package org.opendaylight.bgp.concepts; import com.google.common.base.Preconditions; import io.netty.buffer.ByteBuf; import org.opendaylight.protocol.util.Ipv4Util; import org.opendaylight.protocol.util.Ipv6Util; import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.types.rev130919.next.hop.CNextHop; import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.types.rev130919.next.hop.c.next.hop.EmptyNextHopCase; import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.types.rev130919.next.hop.c.next.hop.Ipv4NextHopCase; import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.types.rev130919.next.hop.c.next.hop.Ipv4NextHopCaseBuilder; import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.types.rev130919.next.hop.c.next.hop.Ipv6NextHopCase; import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.types.rev130919.next.hop.c.next.hop.Ipv6NextHopCaseBuilder; import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.types.rev130919.next.hop.c.next.hop.ipv4.next.hop._case.Ipv4NextHopBuilder; import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.types.rev130919.next.hop.c.next.hop.ipv6.next.hop._case.Ipv6NextHop; import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.types.rev130919.next.hop.c.next.hop.ipv6.next.hop._case.Ipv6NextHopBuilder; /** * Utility class for of CNextHop serialization and parsing. */ public final class NextHopUtil { private NextHopUtil() { throw new UnsupportedOperationException(); } /** * Writes serialized cnextHop IP address as byte value into ByteBuf. * * @param cnextHop next hop to be serialized * @param byteAggregator where the next hop will be written */ public static void serializeNextHop(final CNextHop cnextHop, final ByteBuf byteAggregator) { if (cnextHop instanceof Ipv4NextHopCase) { byteAggregator.writeBytes( Ipv4Util.bytesForAddress(((Ipv4NextHopCase) cnextHop).getIpv4NextHop().getGlobal())); } else if (cnextHop instanceof Ipv6NextHopCase) { final Ipv6NextHop nextHop = ((Ipv6NextHopCase) cnextHop).getIpv6NextHop(); Preconditions.checkArgument(nextHop.getGlobal() != null, "Ipv6 Next Hop is missing Global address."); byteAggregator.writeBytes(Ipv6Util.bytesForAddress(nextHop.getGlobal())); if (nextHop.getLinkLocal() != null) { byteAggregator.writeBytes(Ipv6Util.bytesForAddress(nextHop.getLinkLocal())); } } else if (!(cnextHop instanceof EmptyNextHopCase)) { throw new IllegalArgumentException("Cannot serialize NEXT_HOP. Class not supported: " + cnextHop); } } /** * Parses CNextHop IP address from given ByteBuf. * * @param buffer contains byte array representation of CNextHop * @return CNexthop object */ public static CNextHop parseNextHop(final ByteBuf buffer) { switch (buffer.writerIndex()) { case Ipv4Util.IP4_LENGTH: return new Ipv4NextHopCaseBuilder() .setIpv4NextHop(new Ipv4NextHopBuilder().setGlobal(Ipv4Util.addressForByteBuf(buffer)).build()) .build(); case Ipv6Util.IPV6_LENGTH: return new Ipv6NextHopCaseBuilder() .setIpv6NextHop(new Ipv6NextHopBuilder().setGlobal(Ipv6Util.addressForByteBuf(buffer)).build()) .build(); case Ipv6Util.IPV6_LENGTH * 2: return new Ipv6NextHopCaseBuilder() .setIpv6NextHop(new Ipv6NextHopBuilder().setGlobal(Ipv6Util.addressForByteBuf(buffer)) .setLinkLocal(Ipv6Util.addressForByteBuf(buffer)).build()) .build(); default: throw new IllegalArgumentException( "Cannot parse NEXT_HOP attribute. Wrong bytes length: " + buffer.writerIndex()); } } }