Java Code Examples for org.apache.mina.core.buffer.IoBuffer#position()

@Test
public void testDecodeBuffer() {
    log.debug("\ntestDecodeBuffer");
    RTMPProtocolDecoder dec = new RTMPProtocolDecoder();
    List<Object> objs;
    RTMPConnection conn = new RTMPMinaConnection();
    conn.getState().setState(RTMP.STATE_CONNECTED);
    conn.setHandler(this);
    IoBuffer p00 = IoBuffer.wrap(IOUtils.hexStringToByteArray(
            "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"));
    p00.position(1536);
    objs = dec.decodeBuffer(conn, p00);
    log.debug("Objects #00: {}", objs);
    assertNotNull("Objects should not be null", objs);
    assertFalse("Objects should not be empty", objs.isEmpty());
    assertEquals("Method should be 'connect'", "connect", ((Invoke) ((Packet) objs.get(0)).getMessage()).getCall().getServiceMethodName());

    IoBuffer p01 = IoBuffer.wrap(IOUtils.hexStringToByteArray(
            "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"));
    objs = dec.decodeBuffer(conn, p01);
    log.debug("Objects #01: {}", objs);
}
 

/** {@inheritDoc} */
@Override
public void writeByteArray(ByteArray array) {
    writeAMF3();
    buf.put(AMF3.TYPE_BYTEARRAY);
    if (hasReference(array)) {
        putInteger(getReferenceId(array) << 1);
        return;
    }
    storeReference(array);
    IoBuffer data = array.getData();
    putInteger(data.limit() << 1 | 1);
    byte[] tmp = new byte[data.limit()];
    int old = data.position();
    try {
        data.position(0);
        data.get(tmp);
        buf.put(tmp);
    } finally {
        data.position(old);
    }
}
 

public void encode(IoSession session, Object message, ProtocolEncoderOutput out) throws Exception {
    CharsetEncoder encoder = (CharsetEncoder) session.getAttribute(ENCODER);

    if (encoder == null) {
        encoder = charset.newEncoder();
        session.setAttribute(ENCODER, encoder);
    }

    String value = (message == null ? "" : message.toString());
    IoBuffer buf = IoBuffer.allocate(value.length()).setAutoExpand(true);
    buf.putString(value, encoder);

    if (buf.position() > maxLineLength) {
        throw new IllegalArgumentException("Line length: " + buf.position());
    }

    buf.putString(delimiter.getValue(), encoder);
    buf.flip();
    out.write(buf);
}
 

@Override
protected boolean doDecode(
		IoSession session,
		IoBuffer in,
		ProtocolDecoderOutput out) throws Exception {
	if (!in.hasRemaining()) {
		return false;
	}
	int position = in.position();
	try {
		if (doRealDecode(session, in, out)) {
			return true;
		}
	} catch (Exception e) {
		logger.error("Can not decode message", e);
	}
	in.position(position);
	return false;
}
 

public void writeObject(Object obj) throws IOException {
    IoBuffer buf = IoBuffer.allocate(64, false);
    buf.setAutoExpand(true);
    buf.putObject(obj);

    int objectSize = buf.position() - 4;
    if (objectSize > maxObjectSize) {
        throw new IllegalArgumentException("The encoded object is too big: " + objectSize + " (> " + maxObjectSize
                + ')');
    }

    out.write(buf.array(), 0, buf.position());
}
 

private void discard(IoBuffer in) {
    if (Integer.MAX_VALUE - in.remaining() < overflowPosition) {
        overflowPosition = Integer.MAX_VALUE;
    } else {
        overflowPosition += in.remaining();
    }

    in.position(in.limit());
}
 

public void encode(IoSession session, Object message, ProtocolEncoderOutput out) throws Exception {
    String value = (String) message;
    IoBuffer buffer = IoBuffer.allocate(value.length()).setAutoExpand(true);
    buffer.putPrefixedString(value, prefixLength, charset.newEncoder());
    if (buffer.position() > maxDataLength) {
        throw new IllegalArgumentException("Data length: " + buffer.position());
    }
    buffer.flip();
    out.write(buffer);
}
 

public static byte[] ByteBufferToByteArray(IoBuffer buf) {
    byte[] byteBuf = new byte[buf.limit()];
    int pos = buf.position();
    buf.rewind();
    buf.get(byteBuf);
    buf.position(pos);
    return byteBuf;
}
 

public static ImmutableTag build(byte dataType, int timestamp, IoBuffer data) {
    if (data != null) {
        byte[] body = new byte[data.limit()];
        int pos = data.position();
        data.get(body);
        data.position(pos);
        return new ImmutableTag(dataType, timestamp, body);
    } else {
        return new ImmutableTag(dataType, timestamp, null);
    }
}
 

/**
 * Test decode message testString from bytes and check Alpha_notrim
 */
@Test
public void testStringAlphaNotrimDecode(){
       byte[] array = { 58, 0, 1, 48, 0, 0, 0, 0,
               46, 13, 102, 102, 115, 116, 49, 32,
               32, 32, 49, 48, 58, 52, 57, 58,
               48, 48, 77, 111, 110, 32, 74, 117,
               108, 32, 48, 52, 32, 49, 52, 58,
               48, 50, 58, 51, 48, 32, 77, 83,
               75, 32, 50, 48, 49, 54, 0, 0,
               0, 0, 0, 0, 0, 0, 0, 0, };
  		IoBuffer toDecode = IoBuffer.wrap( array );
	toDecode.order(ByteOrder.LITTLE_ENDIAN);
	toDecode.position(0);

	IoSession decodeSession = new DummySession();
	MockProtocolDecoderOutput decoderOutput = new MockProtocolDecoderOutput();
	try{
		boolean decodableResult = codec.doDecode( decodeSession, toDecode, decoderOutput );
		Assert.assertTrue( "Decoding error.", decodableResult);
		IMessage message=(IMessage) decoderOutput.getMessageQueue().element();
		@SuppressWarnings("unchecked")
           List<IMessage> result = message.getField(ITCHMessageHelper.SUBMESSAGES_FIELD_NAME);
		Assert.assertEquals(2, result.size());
		Assert.assertEquals(1, (int)Integer.valueOf(result.get(1).getField("Alpha_notrim").toString().trim()));
	}catch(Exception e){
		e.printStackTrace(System.err);
		logger.error(e.getMessage(),e);
		Assert.fail(e.getMessage());
	}
}
 

@Override
protected boolean doDecode(IoSession session, IoBuffer in, ProtocolDecoderOutput out)
		throws ProtocolDecoderException, CharacterCodingException {
	if (in.remaining() < 5) {
		return false;
	}
	final int pos = in.position();
	if (!this.innerDecode(session, in, out)) {
		in.position(pos);
		return false;
	}
	return true;
}
 

public static String getFixString(IoBuffer in) throws MessageParseException {
 int offset = in.position();
    byte[] buffer = new byte[in.remaining()];

    in.get(buffer);

    String out = new String(buffer, 0, buffer.length, Charset.forName(CharsetSupport.getCharset()));

    int beginStringIdx = out.indexOf("8=FIX");

    if(beginStringIdx == -1) {
        in.position(offset);
        return null;
    }

    if(beginStringIdx > 0) {
        in.position(offset + beginStringIdx);
        throw new MessageParseException("BeginString index is higher than 0", out);
    }

    int nextBeginStringIdx = out.indexOf("8=FIX", beginStringIdx + 1);

    if(nextBeginStringIdx != -1) {
        out = out.substring(0, nextBeginStringIdx);
    }

    int checkSumIdx = out.indexOf(SOH + "10=");
    int sohIdx = out.indexOf(SOH, checkSumIdx + 1);

    if(checkSumIdx == -1 || sohIdx == -1) {
        if(nextBeginStringIdx != -1) {
            in.position(nextBeginStringIdx);
            throw new MessageParseException("CheckSum is absent or invalid", out);
        }

        in.position(offset);
        return null;
    }

    sohIdx++;

    in.position(offset + sohIdx);

    if(sohIdx < out.length()) {
        out = out.substring(0, sohIdx);
    }

    sohIdx = out.indexOf(SOH);
    int lengthIdx = out.indexOf("9=");

    if(lengthIdx != sohIdx + 1) {
        throw new MessageParseException("BodyLength is absent or not a second tag", out);
    }

    sohIdx = out.indexOf(SOH, lengthIdx);

    try {
        int bodyLength = Integer.parseInt(out.substring(lengthIdx + 2, sohIdx));

        if(bodyLength != checkSumIdx - sohIdx) {
            throw new MessageParseException("BodyLength value differs from actual message length", out);
        }
    } catch(Exception e) {
        throw new MessageParseException("BodyLength value is invalid", out);
    }

    return out;
}
 

/**
 * Decode a line using the delimiter defined by the caller
 */
private void decodeNormal(Context ctx, IoSession session, IoBuffer in, ProtocolDecoderOutput out)
        throws CharacterCodingException, ProtocolDecoderException {
    int matchCount = ctx.getMatchCount();

    // Try to find a match
    int oldPos = in.position();
    int oldLimit = in.limit();

    while (in.hasRemaining()) {
        byte b = in.get();

        if (delimBuf.get(matchCount) == b) {
            matchCount++;

            if (matchCount == delimBuf.limit()) {
                // Found a match.
                int pos = in.position();
                in.limit(pos);
                in.position(oldPos);

                ctx.append(in);

                in.limit(oldLimit);
                in.position(pos);

                if (ctx.getOverflowPosition() == 0) {
                    IoBuffer buf = ctx.getBuffer();
                    buf.flip();
                    buf.limit(buf.limit() - matchCount);

                    try {
                        writeText(session, buf.getString(ctx.getDecoder()), out);
                    } finally {
                        buf.clear();
                    }
                } else {
                    int overflowPosition = ctx.getOverflowPosition();
                    ctx.reset();
                    throw new RecoverableProtocolDecoderException("Line is too long: " + overflowPosition);
                }

                oldPos = pos;
                matchCount = 0;
            }
        } else {
            // fix for DIRMINA-506 & DIRMINA-536
            in.position(Math.max(0, in.position() - matchCount));
            matchCount = 0;
        }
    }

    // Put remainder to buf.
    in.position(oldPos);
    ctx.append(in);

    ctx.setMatchCount(matchCount);
}
 

public DecodingState decode(IoBuffer in, ProtocolDecoderOutput out) throws Exception {
    int beginPos = in.position();
    int limit = in.limit();
    int terminatorPos = -1;

    for (int i = beginPos; i < limit; i++) {
        byte b = in.get(i);
        if (b == CR) {
            lastIsCR = true;
        } else {
            if (b == LF && lastIsCR) {
                terminatorPos = i;
                break;
            }
            lastIsCR = false;
        }
    }

    if (terminatorPos >= 0) {
        IoBuffer product;

        int endPos = terminatorPos - 1;

        if (beginPos < endPos) {
            in.limit(endPos);

            if (buffer == null) {
                product = in.slice();
            } else {
                buffer.put(in);
                product = buffer.flip();
                buffer = null;
            }

            in.limit(limit);
        } else {
            // When input contained only CR or LF rather than actual data...
            if (buffer == null) {
                product = IoBuffer.allocate(0);
            } else {
                product = buffer.flip();
                buffer = null;
            }
        }
        in.position(terminatorPos + 1);
        return finishDecode(product, out);
    }

    in.position(beginPos);

    if (buffer == null) {
        buffer = IoBuffer.allocate(in.remaining());
        buffer.setAutoExpand(true);
    }

    buffer.put(in);

    if (lastIsCR) {
        buffer.position(buffer.position() - 1);
    }

    return this;
}
 

@Override
protected boolean doDecode ( final IoSession session, final IoBuffer data, final ProtocolDecoderOutput output ) throws Exception
{
    logger.trace ( "decode data - session: {}, data: {}", session, data );

    if ( data.remaining () < HEADER_SIZE )
    {
        return false;
    }

    final int position = data.position ();

    final byte version = data.get ( position ); // peek at version
    if ( version != 0x01 )
    {
        throw new IllegalStateException ( String.format ( "Version 0x%02x is not supported.", version ) );
    }

    final int frameTypeOrdinal = data.get ( position + 1 ); // peek at frame type
    final FrameType frameType = FrameType.values ()[frameTypeOrdinal]; // may case an exception, that is ok then

    final int dataLength = data.getInt ( position + 2 ); // we need to look at "here" + 2

    logger.trace ( "Data length: {}, remainingData: {}", dataLength, data.remaining () - 6 );

    if ( data.remaining () < HEADER_SIZE + dataLength )
    {
        return false;
    }

    // consume fields
    data.get (); // version - #0
    data.get (); // frame type - #1
    data.getInt (); // dataLength - #2

    // data - #6
    final IoBuffer frameData = data.getSlice ( dataLength ); // this also consumes the buffer 'data'

    final Frame frame = new Frame ( frameType, frameData );

    logger.trace ( "Decoded frame: {} ... {} bytes remaining", frame, data.remaining () );
    output.write ( frame );

    return true;
}
 

private void sendAVCDecoderConfig(int timecode) {

		IoBuffer buffV = IoBuffer.allocate(_pCodecSetup.length);
		buffV.setAutoExpand(true);
		for (int p = 0; p < _pCodecSetup.length; p++)
			buffV.put((byte) _pCodecSetup[p]);
		buffV.flip();

		buffV.position(0);

		IRTMPEvent video = new VideoData(buffV);

		video.setTimestamp(timecode);

		video.setHeader(new Header());

		if (output != null)
			output.dispatchEvent(video);

	}
 

@Override
public void decode(IoSession session, IoBuffer in, ProtocolDecoderOutput out) throws DhcpException, IOException {
    out.write(decoder.decode(in.buf()));
    in.position(in.limit());    // Consume the remaining bytes, as they will be handed back to us.
}
 

/** {@inheritDoc} */
    @Override
    protected boolean doDecode(IoSession session, IoBuffer in, ProtocolDecoderOutput out) throws Exception {        
        IoBuffer resultBuffer;
        if(!session.containsAttribute(WebSocketUtils.SessionAttribute)){
            // first message on a new connection. see if its from a websocket or a 
            // native socket.
            if(tryWebSockeHandShake(session, in, out)){
                // websocket handshake was successful. Don't write anything to output
                // as we want to abstract the handshake request message from the handler.
                in.position(in.limit());
                return true;
            }
            else{
                // message is from a native socket. Simply wrap and pass through.
                resultBuffer = IoBuffer.wrap(in.array(), 0, in.limit());
                in.position(in.limit());
                session.setAttribute(WebSocketUtils.SessionAttribute, false);
            }
            out.write(resultBuffer);
        }
        else if(session.containsAttribute(WebSocketUtils.SessionAttribute) && true==(Boolean)session.getAttribute(WebSocketUtils.SessionAttribute)){            
            // there is incoming data from the websocket. Decode and send to handler or next filter.     
            int startPos = in.position();
            resultBuffer = buildWSDataBuffer(in, session);
            if(resultBuffer == null){
                // There was not enough data in the buffer to parse. Reset the in buffer
                // position and wait for more data before trying again.
                in.position(startPos);
                return false;
            }
            //转换为byte数组
//            int int1 = resultBuffer.getInt();
           out.write(resultBuffer.array());
        }
        else{
            // session is known to be from a native socket. So
            // simply wrap and pass through.
            resultBuffer = IoBuffer.wrap(in.array(), 0, in.limit());    
            in.position(in.limit());
            out.write(resultBuffer);
        }                        
        return true;
    }
 

@Override
protected boolean doDecode(IoSession session, IoBuffer in, ProtocolDecoderOutput out) throws Exception {
    IoBuffer resultBuffer;
    WebSocketConnection conn = (WebSocketConnection) session.getAttribute(Constants.CONNECTION);
    if (conn == null) {
        log.debug("Decode start pos: {}", in.position());
        // first message on a new connection, check if its from a websocket or a native socket
        if (doHandShake(session, in)) {
            log.debug("Decode end pos: {} limit: {}", in.position(), in.limit());
            // websocket handshake was successful. Don't write anything to output as we want to abstract the handshake request message from the handler
            if (in.position() != in.limit()) {
                in.position(in.limit());
            }
            return true;
        } else if (session.containsAttribute(Constants.WS_HANDSHAKE)) {
            // more still expected to come in before HS is completed
            return false;
        } else {
            // message is from a native socket. Simply wrap and pass through
            resultBuffer = IoBuffer.wrap(in.array(), 0, in.limit());
            in.position(in.limit());
            out.write(resultBuffer);
        }
    } else if (conn.isWebConnection()) {
        // grab decoding state
        DecoderState decoderState = (DecoderState) session.getAttribute(DECODER_STATE_KEY);
        if (decoderState == null) {
            decoderState = new DecoderState();
            session.setAttribute(DECODER_STATE_KEY, decoderState);
        }
        // there is incoming data from the websocket, decode it
        decodeIncommingData(in, session);
        // this will be null until all the fragments are collected
        WSMessage message = (WSMessage) session.getAttribute(DECODED_MESSAGE_KEY);
        if (log.isDebugEnabled()) {
            log.debug("State: {} message: {}", decoderState, message);
        }
        if (message != null) {
            // set the originating connection on the message
            message.setConnection(conn);
            // write the message
            out.write(message);
            // remove decoded message
            session.removeAttribute(DECODED_MESSAGE_KEY);
        } else {
            // there was not enough data in the buffer to parse
            return false;
        }
    } else {
        // session is known to be from a native socket. So simply wrap and pass through
        byte[] arr = new byte[in.remaining()];
        in.get(arr);
        out.write(IoBuffer.wrap(arr));
    }
    return true;
}
 

@Override
public void messageReceived ( final NextFilter nextFilter, final IoSession session, final Object message ) throws Exception
{
    if ( ! ( message instanceof IoBuffer ) )
    {
        nextFilter.messageReceived ( session, message );
        return;
    }

    final IoBuffer in = (IoBuffer)message;
    final IoBuffer sessionBuffer = getSessionBuffer ( session );

    // first add to the session buffer (may be optimized later)
    sessionBuffer.position ( sessionBuffer.limit () );
    sessionBuffer.put ( in );
    sessionBuffer.flip ();

    while ( sessionBuffer.remaining () >= 4 )
    {
        final int len = sessionBuffer.getUnsignedShort ( 2 );
        if ( sessionBuffer.remaining () < len )
        {
            logger.debug ( "Next packet requires {} bytes", new Object[] { len } );
            // not enough data for body
            return;
        }

        // convert
        final IoBuffer data = IoBuffer.allocate ( len - 4 );
        sessionBuffer.get (); // version
        sessionBuffer.get (); // reserved
        sessionBuffer.getUnsignedShort (); // length

        sessionBuffer.get ( data.array () );

        nextFilter.messageReceived ( session, data );

        logger.debug ( "{} bytes left in session buffer", sessionBuffer.remaining () );
    }

    if ( sessionBuffer.hasRemaining () )
    {
        sessionBuffer.compact ();
    }
    else
    {
        sessionBuffer.clear ().flip ();
    }
}