Question

我想从设备读取后写（通过蓝牙插座）问题是当套接字关闭时while（true）完成，所以我不能再写了。

这是代码：

        try {
            // This will block until it succeeds in connecting to the device
            // through the bluetoothSocket or throws an exception
            bluetoothSocket.connect();
            try {
                connectingThread.sleep(1000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            outstream = bluetoothSocket.getOutputStream();
            outstream.write("P".getBytes());
            instream = bluetoothSocket.getInputStream();
            byte[] buffer = new byte[128];  // buffer store for the stream
            int bytes; // bytes returned from read()
            String readMessage = "";

             // Keep listening to the InputStream until an exception occurs
            while (true) {
                try {
                    // Read from the InputStream
                    bytes = instream.read(buffer);
                    if(bytes!= -1){
                    // Send the obtained bytes to the UI activity
                    readMessage = new String(buffer, 0, bytes);

                    arrayList.add(readMessage);
                    biodyMsg = TextUtils.join("", arrayList);
                    }

                } catch (Exception e) {

                    Log.d("Read Error", e.toString());

                }finally {
                    outstream = bluetoothSocket.getOutputStream();
                    outstream.write("F".getBytes());
                }
                break;
            }

        } catch (IOException connectException) {
            connectException.printStackTrace();
            try {    
                bluetoothSocket.close();
            } catch (IOException closeException) {
                closeException.printStackTrace();
            }
        }

Logcat

你能帮助我吗

Answer 1

while (true)循环可以终止的唯一方法是通过break语句，或通过获取未捕获的异常，并且您没有提到获得一个。此代码中有两种可能的例外情况：

IOException：但是使用此代码获取IOException的唯一方法是对等重置连接。
ArrayIndexOutOfBoundsException在构建String时，如果bytes是否定的，则可以是：见下文;但你也没有提到这一点。

你的实际问题是你没有检查bytes是否为-1，这表示流的结束，这反过来表明对等方已关闭连接，这反过来表明你应该关闭套接字和跳出读循环。

读完蓝牙插座android之后写一个输出流

1 个答案: