ProtocolVersionDecoder.java

/*******************************************************************************
 * Copyright (c) 2016 comtel inc.
 *
 * Licensed 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 org.jfxvnc.net.rfb.codec.decoder;

import java.nio.charset.Charset;
import java.nio.charset.StandardCharsets;
import java.util.List;

import org.jfxvnc.net.rfb.codec.ProtocolVersion;

import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelHandlerContext;
import io.netty.handler.codec.ByteToMessageDecoder;

public class ProtocolVersionDecoder extends ByteToMessageDecoder {

  protected final Charset ASCII = StandardCharsets.US_ASCII;

  private final int length = 12;

  public ProtocolVersionDecoder() {
    setSingleDecode(true);
  }

  @Override
  protected void decode(ChannelHandlerContext ctx, ByteBuf in, List<Object> out) throws Exception {
    if (!in.isReadable(length)) {
      return;
    }
    byte[] rfb = new byte[length];
    in.readBytes(rfb);
    String rfbVersion = new String(rfb, ASCII);
    out.add(new ProtocolVersion(rfbVersion));
    ctx.pipeline().remove(this);
  }

}