等到 Java for 循环中出现状态

Question

UPDATE:

I made a new and more specific question here: Implementing wait() and notify() between multiple sensor connections

OLD QUESTION:

I am trying to connect to multiple devices through Bluetooth in my Android app using a single button. It works fairly ok, but sometimes the devices doesn't finish connecting before continuing to the next device in the for loop.

Every sensor connection state can have four states. I would like to have my for loop wait until state 2 has been reached before continuing to the next sensor. Is that possible? I Tried implementing a while loop, but it doesn't work.

public void onConnectSensors() {

    for (int i = 0; i < 10; i++) { // Connect to sensors 0-9

        int state = mScanAdapter.getConnectionState(i);
        BluetoothDevice device = mScanAdapter.getDevice(i);

        switch (state) {

            case CONN_STATE_DISCONNECTED:

                ...

            case CONN_STATE_CONNECTING:

                ...

            case CONN_STATE_CONNECTED:

                ...

            case CONN_STATE_RECONNECTING:

                ...
        }
        while (mScanAdapter.getConnectionState(i) != 2) {
            try {
                wait();          // waits until state 2 has been reached
            } catch (InterruptedException e) {
            }
        }
    }
}

Answer 1

You can try something like this:

public void onConnectSensors() {
    for (int i = 0; i < 10; i++) { // Connect to sensors 0-9

        int state = mScanAdapter.getConnectionState(i);
        BluetoothDevice device = mScanAdapter.getDevice(i);

        while (state != 2) {
            // handle other states here if you want

            try {
                Thread.sleep(1000); //sleep a second before retry
            } catch (Exception e) {
                // handle errors
            }

            state = mScanAdapter.getConnectionState(i);
        }

        // handle state 2 here
    }
}

If state != 2 than code execution will be paused for a sec, than it retries (asks for the state again). I'm sure it can be done without a blocking sleep too if it's a problem.