一、概述
利用WebRTC的DataChannel发送文本数据以及传输文件
二、实例代码演示
1.初始化DataChannel以及注册DataChannel的回调函数
/** * 创建DataChannel * * @param socketId 用户id * @return 数据通道 */ public DataChannel createDataChannel(String socketId, PeerConnection peerConnection) { if (dataChannelInit == null) { /** DataChannel.Init 可配参数说明： ordered：是否保证顺序传输； maxRetransmitTimeMs：重传允许的最长时间； maxRetransmits：重传允许的最大次数； */ dataChannelInit = new DataChannel.Init(); dataChannelInit.ordered = true; // 消息的传递是否有序 true代表有序 dataChannelInit.negotiated = true; // 协商方式 dataChannelInit.id = 0; // 通道ID } if (dataChannel == null) { dataChannel = peerConnection.createDataChannel("dataChannel", dataChannelInit); //注册DataChannel的回调函数 dataChannel.registerObserver(new DataChannel.Observer() { boolean isHeader = true; String suffix = null; int fileLength = 0; long currentLength = 0; boolean isFinish = false; List<byte[]> queue = new ArrayList<>(); // @Override public void onBufferedAmountChange(long l) { } //状态发生改变 @Override public void onStateChange() { } /** * 接收二进制消息时需要定义一个简单的header用于存放文件信息 * 1.filename 文件名 * 2.suffix 后缀名 * 3.totalLength 文件总大小 * @param buffer */ //接收消息 @Override public void onMessage(DataChannel.Buffer buffer) { try { ByteBuffer data = buffer.data; byte[] bytes = new byte[data.capacity()]; Log.e(TAG, "initDataChannel----->onMessage--->" + bytes.length); data.get(bytes); if (dataChannelListener != null) { if (buffer.binary) {//是二进制数据 if (isHeader) { isHeader = false;//为false时就不是第一次，只有第一次需要检测文件后缀 //检测文件后缀 byte[] headerPayload = new byte[200]; System.arraycopy(bytes, 0, headerPayload, 0, 200); String filePath = ByteUtil.getInstance().getStringFromByteArray(headerPayload); byte[] lengthPayload = new byte[200]; System.arraycopy(bytes, 200, lengthPayload, 0, 20); String length = ByteUtil.getInstance().getStringFromByteArray(lengthPayload); Log.e(TAG, "initDataChannel----->onMessage--->filePath---->" + filePath); Log.e(TAG, "initDataChannel----->onMessage--->length---->" + length); suffix = FileUtils.getInstance().getFileSuffix(filePath); fileLength = Integer.parseInt(length) - 220; Log.e(TAG, "initDataChannel----->onMessage--->suffix---->" + suffix); } if (!isHeader) { currentLength += bytes.length; if ((currentLength - 220) >= fileLength) { isFinish = true; } queue.add(bytes); float progress = (currentLength / (float) fileLength) * 100; dataChannelListener.onReceiveFileProgress(progress); } if (isFinish) { String realPath = null; // for (int i = 0; i < queue.size(); i++) { // isFinish = false; // if (i == queue.size() - 1) { // isFinish = true; // } // //// // } queue.remove(0); realPath = FileUtils.getInstance().writeBytesToFile(context, suffix, queue); if (realPath != null) { Log.e(TAG, "initDataChannel----->onMessage--->realPath----> 执行了多少次"); dataChannelListener.onReceiveBinaryMessage(socketId, realPath); } } } else {//不是二进制数据 //此处接收的是非二进制数据 String msg = new String(bytes); dataChannelListener.onReceiveMessage(socketId, msg); } } } catch (Exception e) { e.printStackTrace(); } } }); } return dataChannel; }
2.接收及发送文本消息
/** * 使用DataChannel发送普通消息 * * @param message */ public void sendMsg(String message) { if (dataChannel != null) { if (message != null) { byte[] msg = message.getBytes(); DataChannel.Buffer buffer = new DataChannel.Buffer(ByteBuffer.wrap(msg), false); dataChannel.send(buffer); } } }
//接收普通文本消息 client.setDataChannelListener(new DataChannelListenerImpl() { @Override public void onReceiveMessage(String userId, String message) { mainHandler.post(() -> { sb.append(userId).append(":").append(message).append("\n"); tvContent.setText(sb.toString()); }); } });
3.接收及发送文件
/** * 使用DataChannel发送二进制消息 * * @param bytes */ public void sendBinary(byte[] bytes) { if (dataChannel != null) { DataChannel.Buffer buffer = new DataChannel.Buffer(ByteBuffer.wrap(bytes), true); dataChannel.send(buffer); } }
client.setDataChannelListener(new DataChannelListenerImpl() { //接收文件消息成功回调以及，显示文件接收的进度 @Override public void onReceiveBinaryMessage(String userId, String realPath) { handler.post(() -> { tvReceiveFileName.setText(realPath); }); } @Override public void onReceiveFileProgress(float progress) { handler.post(() -> { tvReceiveFileName.setText(progress+"%"); }); } });