How to block with a custom implementation of InputStream

I am trying to mock a connection with an Inputstream:

private static class MockInputStream extends InputStream {

    @Override
    public int read() throws IOException {
        //how do I block here until data is available?
        return someData;
    }
}

The reason I am doing this is to simulate a connection between my device and a microcontroller for testing purposes.

My problem is getting the InputStream to 'block' when read is called. Do I just sleep indefinitely until my thread is interrupted when data is available?

private static class MockInputStream extends InputStream {

    private int someData;
    private Thread blockedThread;

    public void setData(int i) {
        this.someData = i;
        blockedThread.interrupt();
    }

    @Override
    public int read() throws IOException {
        blockThread = Thread.currentThread();
        try {
            Thread.sleep(Long.MAX_VALUE);
        } catch (InterruptedException e) {
            return someData;
        }
    }
}

Obviously, the read() is being called from a separate thread