PortMixer.java 文件源码

public void open() throws LineUnavailableException {
    synchronized (mixer) {
        // if the line is not currently open, try to open it with this format and buffer size
        if (!isOpen()) {
            if (Printer.trace) Printer.trace("> PortMixerPort: open");
            // reserve mixer resources for this line
            mixer.open(this);
            try {
                // open the line.  may throw LineUnavailableException.
                implOpen();

                // if we succeeded, set the open state to true and send events
                setOpen(true);
            } catch (LineUnavailableException e) {
                // release mixer resources for this line and then throw the exception
                mixer.close(this);
                throw e;
            }
            if (Printer.trace) Printer.trace("< PortMixerPort: open succeeded");
        }
    }
}