蓝牙socket读取数据需读多次才读全

今天上班解决了一个问题：android程序通过蓝牙socket读取数据时，需要读多次才能把完整的响应APDU读全。当前用的方法来自android示例程序：

public void run() {    Log.i(TAG, "BEGIN mConnectedThread");    byte[] buffer = new byte[1024];    int bytes;    // Keep listening to the InputStream while connected    while (true) {        try {            // Read from the InputStream        Log.i(TAG, "Read from the InputStream...");            bytes = mmInStream.read(buffer);                                Log.i(TAG, "Read from the InputStream, length is "+bytes);            // Send the obtained bytes to the UI Activity            mHandler.obtainMessage(BluetoothChat.MESSAGE_READ, bytes, -1, buffer)                    .sendToTarget();        } catch (IOException e) {            Log.e(TAG, "disconnected", e);            connectionLost();            break;        }    }}

响应APDU是

02001580FFFFFFFF00A4040010D15600010180038000000001000000006A03，

接收三次，每次的结果都不一样：

（1）02001580FFFFFFFF00A4040010D1560001018003 8000000001000000006A 03

（2）02 001580FFFFFFFF00A4040010D15600010180038000000001000000006A 03

（3）02001580FFFFFFFF00A4040010D15600010180038000000001000000006A 03

修改示例代码：响应APDU是可以解析的，第3个字节的值加上10就等于响应APDU的长度，其中10是前缀和后缀的长度之和。

public void run() {Log.i(TAG, "BEGIN mConnectedThread");byte[] buffer = new byte[1024];// int bytes;int len = 0;int i = 0;// Keep listening to the InputStream while connectedwhile (true) {try {// Read from the InputStreamLog.i(TAG, "Read from the InputStream...");// bytes = mmInStream.read(buffer);buffer[i++] = (byte) mmInStream.read();if (i == 3) {len = buffer[2] + 10;}Log.i(TAG, "Read from the InputStream, data is "+ buffer[i - 1]);if (i == len) {// Send the obtained bytes to the UI ActivitymHandler.obtainMessage(BluetoothChat.MESSAGE_READ, len,-1, buffer).sendToTarget();len = 0;i = 0;}} catch (IOException e) {Log.e(TAG, "disconnected", e);connectionLost();break;}}}

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