当我调用bufferedReader.readLine（）时，我的Android应用程序冻结了；

Question

I created a new Android Studio project for an Android phone and an Android Wear to test the ChannelApi . It seems that everything works fine in my project, except that inside the onChannelOpened method I cannot read from InputStream without freezing the app.

This is how I send the message from the Wearable (which seems to work):

Wearable.ChannelApi.openChannel(googleApiClient, node.getId(), channelIdentifier).setResultCallback(new ResultCallback<ChannelApi.OpenChannelResult>() {
    @Override
    public void onResult(ChannelApi.OpenChannelResult openChannelResult) {
        final Channel channel = openChannelResult.getChannel();
        channel.getOutputStream(googleApiClient).setResultCallback(new ResultCallback<Channel.GetOutputStreamResult>() {
        @Override
        public void onResult(final Channel.GetOutputStreamResult getOutputStreamResult) {
        final String message = "hello from your smartwatch";
        try {
            getOutputStreamResult.getOutputStream().write(message.getBytes());
            Log.d(TAG, "sendMessageToNode: onResult: onResult: Message sent: " + message);
        }
        // ...

The log prints: D/MainActivity﹕ sendMessageToNode: onResult: onResult: Message sent: hello from your smartwatch

On the smartphone side I try to read the message as follows:

@Override
public void onChannelOpened(final Channel channel) {
    channel.getInputStream(googleApiClient).setResultCallback(new ResultCallback<Channel.GetInputStreamResult>() {
        @Override
        public void onResult(Channel.GetInputStreamResult getInputStreamResult) {
            Log.d(TAG, "onChannelOpened: onResult");

            String message = "";
            InputStream inputStream = null;
            BufferedReader bufferedReader = null;
            try {
                inputStream = getInputStreamResult.getInputStream();
                bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
                String line = "";
                //while ((line = bufferedReader.readLine()) != null) {
                while (true) {
                    // Next line is freezing the app
                    line = bufferedReader.readLine();
                    Log.d(TAG, "onChannelOpened: onResult: line: " + line);
                    message += line + "\n";
                    if (line == null) break;
                }
                Log.d(TAG, "onChannelOpened: onResult: Received the following message: \" + message");
                // ...

The log prints: D/MainActivity﹕ onChannelOpened: onResult but that's it.

I started the debugger and now know that the error must be in this line: line = bufferedReader.readLine(); . But there is no exception thrown or anything else. The debugger even shows me that the buffer has the right values:

I am trying to send "hello from your smartwatch". However, the app seems to freeze. Does anyone know why?

Answer 1

您需要在发送方关闭流，否则接收方将不知道是否有更多数据通过该通道流失。