import com.sun.jmx.examples.scandir.ScanManagerMXBean.ScanState; //导入依赖的package包/类
/**
 * Enqueue a state changed notification for the given states.
 **/
private void queueStateChangedNotification(
                long sequence,
                long time,
                ScanState old,
                ScanState current) {
    final AttributeChangeNotification n =
            new AttributeChangeNotification(SCAN_MANAGER_NAME,sequence,time,
            "ScanManager State changed to "+current,"State",
            ScanState.class.getName(),old.toString(),current.toString());
    // Queue the notification. We have created an unlimited queue, so
    // this method should always succeed.
    try {
        if (!pendingNotifs.offer(n,2,TimeUnit.SECONDS)) {
            LOG.fine("Can't queue Notification: "+n);
        }
    } catch (InterruptedException x) {
            LOG.fine("Can't queue Notification: "+x);
    }
}
 

import com.sun.jmx.examples.scandir.ScanManagerMXBean.ScanState; //导入依赖的package包/类
/**
 * Checks that the current state is one of the allowed states,
 * and if so, switch its value to the new desired state.
 * This operation also enqueue the appropriate state changed
 * notification.
 **/
private ScanState switchState(ScanState desired,EnumSet<ScanState> allowed) {
    final ScanState old;
    final long timestamp;
    final long sequence;
    synchronized(this) {
        old = state;
        if (!allowed.contains(state))
           throw new IllegalStateException(state.toString());
        state = desired;
        timestamp = System.currentTimeMillis();
        sequence  = getNextSeqNumber();
    }
    LOG.fine("switched state: "+old+" -> "+desired);
    if (old != desired)
        queueStateChangedNotification(sequence,timestamp,old,desired);
    return old;
}
 

import com.sun.jmx.examples.scandir.ScanManagerMXBean.ScanState; //导入依赖的package包/类
public void schedule(long delay, long interval) {
    if (!sequencer.tryAcquire()) {
        throw new IllegalStateException("Can't acquire lock");
    }
    try {
        LOG.fine("scheduling new task: state="+state);
        final ScanState old = switchState(SCHEDULED,"schedule");
        final boolean scheduled =
            scheduleSession(new SessionTask(interval),delay);
        if (scheduled)
            LOG.fine("new task scheduled: state="+state);
    } finally {
        sequencer.release();
    }
    sendQueuedNotifications();
}
 

import com.sun.jmx.examples.scandir.ScanManagerMXBean.ScanState; //导入依赖的package包/类
/**
 * Test of getState method, of class com.sun.jmx.examples.scandir.DirectoryScanner.
 */
public void testGetState() {
    System.out.println("getState");

    final DirectoryScannerConfig bean =
            new DirectoryScannerConfig("test");
    bean.setRootDirectory(System.getProperty("java.io.tmpdir"));
    final ResultLogManager log = new ResultLogManager();
    DirectoryScanner instance =
            new DirectoryScanner(bean,log);

    ScanState expResult = STOPPED;
    ScanState result = instance.getState();
    assertEquals(STOPPED, result);
    instance.scan();
    result = instance.getState();
    assertEquals(COMPLETED, result);
}
 

import com.sun.jmx.examples.scandir.ScanManagerMXBean.ScanState; //导入依赖的package包/类
/**
 * Test of getState method, of class com.sun.jmx.examples.scandir.ScanManager.
 */
public void testGetState() throws IOException, InstanceNotFoundException {
    System.out.println("getState");

    ScanManager instance = new ScanManager();

    ScanState expResult = ScanState.STOPPED;
    ScanState result = instance.getState();
    assertEquals(expResult, result);
    instance.start();
    final ScanState afterStart = instance.getState();
    assertContained(EnumSet.of(RUNNING,SCHEDULED,COMPLETED),afterStart);
    instance.stop();
    assertEquals(STOPPED,instance.getState());
    instance.schedule(1000000L,1000000L);
    assertEquals(SCHEDULED,instance.getState());
    instance.stop();
    assertEquals(STOPPED,instance.getState());
}