com.litongjava.tio.websocket.common.WebSocketServerDecoder Maven / Gradle / Ivy

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package com.litongjava.tio.websocket.common;

import java.nio.ByteBuffer;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.litongjava.tio.core.ChannelContext;
import com.litongjava.tio.core.exception.TioDecodeException;
import com.litongjava.tio.core.utils.ByteBufferUtils;

/**
 *
 * @author tanyaowu
 * 2017年7月30日 上午10:10:50
 */
public class WebSocketServerDecoder {
  public static enum Step {
    header, remain_header, data,
  }

  private static Logger log = LoggerFactory.getLogger(WebSocketServerDecoder.class);

  public static WebSocketRequest decode(ByteBuffer buf, ChannelContext channelContext) throws TioDecodeException {
    // WsSessionContext imSessionContext = (WsSessionContext) channelContext.get();
    // List lastParts = imSessionContext.getLastParts();

    // 第一阶段解析
    int initPosition = buf.position();
    int readableLength = buf.limit() - initPosition;

    int headLength = WebSocketPacket.MINIMUM_HEADER_LENGTH;

    if (readableLength < headLength) {
      return null;
    }

    byte first = buf.get();
    // int b = first & 0xFF; //转换成32位
    boolean fin = (first & 0x80) > 0; // 得到第8位 10000000>0
    @SuppressWarnings("unused")
    int rsv = (first & 0x70) >>> 4; // 得到5、6、7 为01110000 然后右移四位为00000111
    byte opCodeByte = (byte) (first & 0x0F); // 后四位为opCode 00001111
    Opcode opcode = Opcode.valueOf(opCodeByte);
    if (opcode == Opcode.CLOSE) {
      // Tio.remove(channelContext, "收到opcode:" + opcode);
      // return null;
    }
    // if (!fin) {
    // log.error("{} 暂时不支持fin为false的请求", channelContext);
    // Tio.remove(channelContext, "暂时不支持fin为false的请求");
    // return null;
    // //下面这段代码不要删除，以后若支持fin，则需要的
    // // if (lastParts == null) {
    // // lastParts = new ArrayList<>();
    // // imSessionContext.setLastParts(lastParts);
    // // }
    // } else {
    // imSessionContext.setLastParts(null);
    // }

    byte second = buf.get(); // 向后读取一个字节
    boolean hasMask = (second & 0xFF) >> 7 == 1; // 用于标识PayloadData是否经过掩码处理。如果是1，Masking-key域的数据即是掩码密钥，用于解码PayloadData。客户端发出的数据帧需要进行掩码处理，所以此位是1。

    // Client data must be masked
    if (!hasMask) { // 第9为为mask,必须为1
      // throw new TioDecodeException("websocket client data must be masked");
    } else {
      headLength += 4;
    }
    int payloadLength = second & 0x7F; // 读取后7位 Payload legth，如果<126则payloadLength

    byte[] mask = null;
    if (payloadLength == 126) { // 为126读2个字节，后两个字节为payloadLength
      headLength += 2;
      if (readableLength < headLength) {
        return null;
      }
      payloadLength = ByteBufferUtils.readUB2WithBigEdian(buf);
      log.info("{} payloadLengthFlag: 126，payloadLength {}", channelContext, payloadLength);

    } else if (payloadLength == 127) { // 127读8个字节,后8个字节为payloadLength
      headLength += 8;
      if (readableLength < headLength) {
        return null;
      }

      payloadLength = (int) buf.getLong();
      log.info("{} payloadLengthFlag: 127，payloadLength {}", channelContext, payloadLength);
    }

    if (payloadLength < 0 || payloadLength > WebSocketPacket.MAX_BODY_LENGTH) {
      throw new TioDecodeException("body length(" + payloadLength + ") is not right");
    }

    if (readableLength < headLength + payloadLength) {
      return null;
    }

    if (hasMask) {
      mask = ByteBufferUtils.readBytes(buf, 4);
    }

    // 第二阶段解析
    WebSocketRequest websocketPacket = new WebSocketRequest();
    websocketPacket.setWsEof(fin);
    websocketPacket.setWsHasMask(hasMask);
    websocketPacket.setWsMask(mask);
    websocketPacket.setWsOpcode(opcode);
    websocketPacket.setWsBodyLength(payloadLength);

    if (payloadLength == 0) {
      return websocketPacket;
    }

    byte[] array = ByteBufferUtils.readBytes(buf, payloadLength);
    if (hasMask) {
      for (int i = 0; i < array.length; i++) {
        array[i] = (byte) (array[i] ^ mask[i % 4]);
      }
    }

    websocketPacket.setBody(array);

    // if (!fin) {
    // //lastParts.add(array);
    // log.error("payloadLength {}, lastParts size {}, array length {}", payloadLength,
    // lastParts.size(), array.length);
    // return websocketPacket;
    // } else {
    // int allLength = array.length;
    // if (lastParts != null) {
    // for (byte[] part : lastParts) {
    // allLength += part.length;
    // }
    // byte[] allByte = new byte[allLength];
    //
    // int offset = 0;
    // for (byte[] part : lastParts) {
    // System.arraycopy(part, 0, allByte, offset, part.length);
    // offset += part.length;
    // }
    // System.arraycopy(array, 0, allByte, offset, array.length);
    // array = allByte;
    // }
    //
    // websocketPacket.setBody(array);
    //
    // if (opcode == Opcode.BINARY) {
    //
    // } else {
    // try {
    // String text = null;
    // text = new String(array, WsPacket.CHARSET_NAME);
    // websocketPacket.setWsBodyText(text);
    // } catch (UnsupportedEncodingException e) {
    // log.error(e.toString(), e);
    // }
    // }
    // }

//		if (fin && opcode != null) {
//			if (opcode == Opcode.BINARY) {
//
//			} else {
//				try {
//					String text = new String(array, WsPacket.CHARSET_NAME);
//					websocketPacket.setWsBodyText(text);
//				} catch (UnsupportedEncodingException e) {
//					log.error(e.toString(), e);
//				}
//			}
//		}
    return websocketPacket;
  }

  /** @author tanyaowu 2017年2月22日 下午4:06:42 */
  public WebSocketServerDecoder() {
  }
}