Java tutorial
/* * Copyright 2012 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.socks; import io.netty.buffer.ByteBuf; import io.netty.channel.ChannelHandlerContext; import io.netty.handler.codec.ReplayingDecoder; import io.netty.handler.codec.socks.SocksInitRequestDecoder.State; import java.util.ArrayList; import java.util.Collections; import java.util.List; /** * Decodes {@link ByteBuf}s into {@link SocksInitRequest}. * Before returning SocksRequest decoder removes itself from pipeline. */ public class SocksInitRequestDecoder extends ReplayingDecoder<State> { public SocksInitRequestDecoder() { super(State.CHECK_PROTOCOL_VERSION); } @Override protected void decode(ChannelHandlerContext ctx, ByteBuf byteBuf, List<Object> out) throws Exception { switch (state()) { case CHECK_PROTOCOL_VERSION: { if (byteBuf.readByte() != SocksProtocolVersion.SOCKS5.byteValue()) { out.add(SocksCommonUtils.UNKNOWN_SOCKS_REQUEST); break; } checkpoint(State.READ_AUTH_SCHEMES); } case READ_AUTH_SCHEMES: { final byte authSchemeNum = byteBuf.readByte(); final List<SocksAuthScheme> authSchemes; if (authSchemeNum > 0) { authSchemes = new ArrayList<SocksAuthScheme>(authSchemeNum); for (int i = 0; i < authSchemeNum; i++) { authSchemes.add(SocksAuthScheme.valueOf(byteBuf.readByte())); } } else { authSchemes = Collections.emptyList(); } out.add(new SocksInitRequest(authSchemes)); break; } default: { throw new Error(); } } ctx.pipeline().remove(this); } enum State { CHECK_PROTOCOL_VERSION, READ_AUTH_SCHEMES } }