Java MidiDevice.close方法代碼示例

import javax.sound.midi.MidiDevice; //導入方法依賴的package包/類
/**
 * Closes the MIDI device.
 *
 * @param device the MIDI device.
 */
public static void close(MidiDevice device) {
    try {
        if (device != null && device.isOpen()) {
            device.close();
        }
    } catch (Exception e) {
        logger.warn("close", e);
    }
}
 

import javax.sound.midi.MidiDevice; //導入方法依賴的package包/類
public static void main(String[] args) throws Exception {
    MidiDevice/*Synthesizer*/ synth = null;

    try {
        synth = MidiSystem.getSynthesizer();
        //synth = MidiSystem.getMidiDevice(infos[0]);

        System.out.println("Synthesizer: " + synth.getDeviceInfo());
        synth.open();
        MidiMessage msg = new GenericMidiMessage(0x90, 0x3C, 0x40);
        //ShortMessage msg = new ShortMessage();
        //msg.setMessage(0x90, 0x3C, 0x40);

        synth.getReceiver().send(msg, 0);
        Thread.sleep(2000);

    } catch (Exception ex) {
        ex.printStackTrace();
        throw ex;
    } finally {
        if (synth != null && synth.isOpen())
            synth.close();
    }
    System.out.print("Did you heard a note? (enter 'y' or 'n') ");
    int result = System.in.read();
    System.in.skip(1000);
    if (result == 'y' || result == 'Y')
    {
        System.out.println("Test passed sucessfully.");
    }
    else
    {
        System.out.println("Test FAILED.");
        throw new RuntimeException("Test failed.");
    }
}
 

import javax.sound.midi.MidiDevice; //導入方法依賴的package包/類
private static boolean doTest(int numIterations, boolean input) throws Exception {
    MidiDevice.Info[] infos = MidiSystem.getMidiDeviceInfo();
    MidiDevice outDevice = null;
    MidiDevice inDevice = null;
    for (int i = 0; i < infos.length; i++) {
        MidiDevice device = MidiSystem.getMidiDevice(infos[i]);
        if (! (device instanceof Sequencer) &&
            ! (device instanceof Synthesizer)) {
            if (device.getMaxReceivers() != 0) {
                outDevice = device;
            }
            if (device.getMaxTransmitters() != 0) {
                inDevice = device;
            }
        }
    }
    MidiDevice testDevice = null;
    if (input) {
        testDevice = inDevice;
    } else {
        testDevice = outDevice;
    }
    if (testDevice == null) {
        out("Cannot test: device not available.");
        return true;
    }
    out("Using Device: " + testDevice);

    for (int i = 0; i < numIterations; i++) {
        out("@@@ ITERATION: " + i);
        testDevice.open();
        // This sleep ensures that the thread of MidiInDevice is started.
        sleep(50);
        testDevice.close();
    }
    return true;
}
 

import javax.sound.midi.MidiDevice; //導入方法依賴的package包/類
private static void unuseDevice(MidiDevice device)
{
    Integer i = deviceUsage.get(device);
    if (i == null) return;
    else if (i <= 1)
    {
        device.close();
        deviceUsage.remove(device);
    }
    else deviceUsage.put(device, i - 1);
}
 

import javax.sound.midi.MidiDevice; //導入方法依賴的package包/類
private static void unuseDevice(MidiDevice device)
{
    Integer i = USAGE.get(device);
    if (i == null) return;
    else if (i <= 1)
    {
        device.close();
        TIME.remove(device);
        USAGE.remove(device);
    }
    else USAGE.put(device, i - 1);
}
 

import javax.sound.midi.MidiDevice; //導入方法依賴的package包/類
private static void testDevice(MidiDevice device) throws Exception {
    boolean timestampsAvailable = false;
    boolean timestampPrecisionOk = false;
    try {
        // expected behaviour if not opened?
        device.open();
        /* First, we're testing if timestamps are provided at all.
           Returning -1 (unsupported), while allowed by the API
           specification, is not sufficient to pass this test. */
        long timestamp = device.getMicrosecondPosition();
        timestampsAvailable = (timestamp != -1);

        /* Then, we're testing the precision. Note that the system time
           is measured in milliseconds, while the device time is measured
           in microseconds. */

        long systemTime1 = System.currentTimeMillis();
        long deviceTime1 = device.getMicrosecondPosition();
        // rest for 5 seconds
        Thread.sleep(5000);
        long systemTime2 = System.currentTimeMillis();
        long deviceTime2 = device.getMicrosecondPosition();

        // now both period measurements are calculated in milliseconds.
        long systemDuration = systemTime2 - systemTime1;
        long deviceDuration = (deviceTime2 - deviceTime1) / 1000;
        long delta = Math.abs(systemDuration - deviceDuration);
        // a deviation of 0.5 seconds (= 500 ms) is allowed.
        timestampPrecisionOk = (delta <= 500);
    } catch (Throwable t) {
        System.out.println("  - Caught exception. Not failed.");
        System.out.println("  - " + t.toString());
        return;
    } finally {
        device.close();
    }
    if (! timestampsAvailable) {
        throw new Exception("timestamps are not supported");
    }
    if (! timestampPrecisionOk) {
        throw new Exception("device timer not precise enough");
    }
    successfulTests++;
}