Java tutorial
/* * Copyright 2014 The Netty Project * * The Netty Project licenses this file to you under the Apache License, * version 2.0 (the "License"); you may not use this file except in compliance * with the License. You may obtain a copy of the License at: * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the * License for the specific language governing permissions and limitations * under the License. */ package io.netty.handler.codec.socksx.v5; import io.netty.buffer.ByteBuf; import io.netty.channel.ChannelHandler.Sharable; import io.netty.channel.ChannelHandlerContext; import io.netty.handler.codec.EncoderException; import io.netty.handler.codec.MessageToByteEncoder; import io.netty.util.internal.ObjectUtil; import io.netty.util.internal.StringUtil; /** * Encodes a server-side {@link Socks5Message} into a {@link ByteBuf}. */ @Sharable public class Socks5ServerEncoder extends MessageToByteEncoder<Socks5Message> { public static final Socks5ServerEncoder DEFAULT = new Socks5ServerEncoder(Socks5AddressEncoder.DEFAULT); private final Socks5AddressEncoder addressEncoder; /** * Creates a new instance with the default {@link Socks5AddressEncoder}. */ protected Socks5ServerEncoder() { this(Socks5AddressEncoder.DEFAULT); } /** * Creates a new instance with the specified {@link Socks5AddressEncoder}. */ public Socks5ServerEncoder(Socks5AddressEncoder addressEncoder) { this.addressEncoder = ObjectUtil.checkNotNull(addressEncoder, "addressEncoder"); } /** * Returns the {@link Socks5AddressEncoder} of this encoder. */ protected final Socks5AddressEncoder addressEncoder() { return addressEncoder; } @Override protected void encode(ChannelHandlerContext ctx, Socks5Message msg, ByteBuf out) throws Exception { if (msg instanceof Socks5InitialResponse) { encodeAuthMethodResponse((Socks5InitialResponse) msg, out); } else if (msg instanceof Socks5PasswordAuthResponse) { encodePasswordAuthResponse((Socks5PasswordAuthResponse) msg, out); } else if (msg instanceof Socks5CommandResponse) { encodeCommandResponse((Socks5CommandResponse) msg, out); } else { throw new EncoderException("unsupported message type: " + StringUtil.simpleClassName(msg)); } } private static void encodeAuthMethodResponse(Socks5InitialResponse msg, ByteBuf out) { out.writeByte(msg.version().byteValue()); out.writeByte(msg.authMethod().byteValue()); } private static void encodePasswordAuthResponse(Socks5PasswordAuthResponse msg, ByteBuf out) { out.writeByte(0x01); out.writeByte(msg.status().byteValue()); } private void encodeCommandResponse(Socks5CommandResponse msg, ByteBuf out) throws Exception { out.writeByte(msg.version().byteValue()); out.writeByte(msg.status().byteValue()); out.writeByte(0x00); final Socks5AddressType bndAddrType = msg.bndAddrType(); out.writeByte(bndAddrType.byteValue()); addressEncoder.encodeAddress(bndAddrType, msg.bndAddr(), out); out.writeShort(msg.bndPort()); } }