java - 当我调用 bufferedReader.readLine() 时，我的 Android 应用程序卡住了；

Question

我为 Android 手机和 Android Wear 创建了一个新的 Android Studio 项目来测试 ChannelApi .在我的项目中似乎一切正常，除了在 onChannelOpened 方法中我无法在不卡住应用程序的情况下从 InputStream 中读取。

这就是我从可穿戴设备发送消息的方式(这似乎有效):

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);
        }
        // ...

日志打印:D/MainActivity:sendMessageToNode: onResult: onResult: Message sent: hello from your smartwatch

在智能手机端，我尝试按如下方式阅读消息:

@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");
                // ...

日志打印:D/MainActivity:onChannelOpened: onResult 但仅此而已。

我启动了调试器，现在知道错误一定在这一行:line = bufferedReader.readLine();。但是没有抛出异常或其他任何东西。调试器甚至告诉我缓冲区有正确的值:

我正在尝试发送“来自您的智能 watch 的问候”。但是，该应用程序似乎卡住了。有谁知道为什么吗？

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 channel 传输。