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	/*
	* Copyright (c) 1999, 2007, Oracle and/or its affiliates. All rights reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 only, as
	* published by the Free Software Foundation. Oracle designates this
	* particular file as subject to the "Classpath" exception as provided
	* by Oracle in the LICENSE file that accompanied this code.
	*
	* This code is distributed in the hope that it will be useful, but WITHOUT
	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
	* version 2 for more details (a copy is included in the LICENSE file that
	* accompanied this code).
	*
	* You should have received a copy of the GNU General Public License version
	* 2 along with this work; if not, write to the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*/

	package javax.management.monitor;

	import static com.sun.jmx.defaults.JmxProperties.MONITOR_LOGGER;
	import java.util.logging.Level;
	import javax.management.ObjectName;
	import javax.management.MBeanNotificationInfo;
	import static javax.management.monitor.MonitorNotification.*;

	/**
	* Defines a monitor MBean designed to observe the values of a string
	* attribute.
	* <P>
	* A string monitor sends notifications as follows:
	* <UL>
	* <LI> if the attribute value matches the string to compare value,
	* a {@link MonitorNotification#STRING_TO_COMPARE_VALUE_MATCHED
	* match notification} is sent.
	* The notify match flag must be set to <CODE>true</CODE>.
	* <BR>Subsequent matchings of the string to compare values do not
	* cause further notifications unless
	* the attribute value differs from the string to compare value.
	* <LI> if the attribute value differs from the string to compare value,
	* a {@link MonitorNotification#STRING_TO_COMPARE_VALUE_DIFFERED
	* differ notification} is sent.
	* The notify differ flag must be set to <CODE>true</CODE>.
	* <BR>Subsequent differences from the string to compare value do
	* not cause further notifications unless
	* the attribute value matches the string to compare value.
	* </UL>
	*
	*
	* @since 1.5
	*/
	public class StringMonitor extends Monitor implements StringMonitorMBean {

	/*
	* ------------------------------------------
	* PACKAGE CLASSES
	* ------------------------------------------
	*/

	static class StringMonitorObservedObject extends ObservedObject {

	public StringMonitorObservedObject(ObjectName observedObject) {
	super(observedObject);
	}

	public final synchronized int getStatus() {
	return status;
	}
	public final synchronized void setStatus(int status) {
	this.status = status;
	}

	private int status;
	}

	/*
	* ------------------------------------------
	* PRIVATE VARIABLES
	* ------------------------------------------
	*/

	/**
	* String to compare with the observed attribute.
	* <BR>The default value is an empty character sequence.
	*/
	private String stringToCompare = "";

	/**
	* Flag indicating if the string monitor notifies when matching
	* the string to compare.
	* <BR>The default value is set to <CODE>false</CODE>.
	*/
	private boolean notifyMatch = false;

	/**
	* Flag indicating if the string monitor notifies when differing
	* from the string to compare.
	* <BR>The default value is set to <CODE>false</CODE>.
	*/
	private boolean notifyDiffer = false;

	private static final String[] types = {
	RUNTIME_ERROR,
	OBSERVED_OBJECT_ERROR,
	OBSERVED_ATTRIBUTE_ERROR,
	OBSERVED_ATTRIBUTE_TYPE_ERROR,
	STRING_TO_COMPARE_VALUE_MATCHED,
	STRING_TO_COMPARE_VALUE_DIFFERED
	};

	private static final MBeanNotificationInfo[] notifsInfo = {
	new MBeanNotificationInfo(
	types,
	"javax.management.monitor.MonitorNotification",
	"Notifications sent by the StringMonitor MBean")
	};

	// Flags needed to implement the matching/differing mechanism.
	//
	private static final int MATCHING = 0;
	private static final int DIFFERING = 1;
	private static final int MATCHING_OR_DIFFERING = 2;

	/*
	* ------------------------------------------
	* CONSTRUCTORS
	* ------------------------------------------
	*/

	/**
	* Default constructor.
	*/
	public StringMonitor() {
	}

	/*
	* ------------------------------------------
	* PUBLIC METHODS
	* ------------------------------------------
	*/

	/**
	* Starts the string monitor.
	*/
	public synchronized void start() {
	if (isActive()) {
	MONITOR_LOGGER.logp(Level.FINER, StringMonitor.class.getName(),
	"start", "the monitor is already active");
	return;
	}
	// Reset values.
	//
	for (ObservedObject o : observedObjects) {
	final StringMonitorObservedObject smo =
	(StringMonitorObservedObject) o;
	smo.setStatus(MATCHING_OR_DIFFERING);
	}
	doStart();
	}

	/**
	* Stops the string monitor.
	*/
	public synchronized void stop() {
	doStop();
	}

	// GETTERS AND SETTERS
	//--------------------

	/**
	* Gets the derived gauge of the specified object, if this object is
	* contained in the set of observed MBeans, or <code>null</code> otherwise.
	*
	* @param object the name of the MBean whose derived gauge is required.
	*
	* @return The derived gauge of the specified object.
	*
	*/
	@Override
	public synchronized String getDerivedGauge(ObjectName object) {
	return (String) super.getDerivedGauge(object);
	}

	/**
	* Gets the derived gauge timestamp of the specified object, if
	* this object is contained in the set of observed MBeans, or
	* <code>0</code> otherwise.
	*
	* @param object the name of the object whose derived gauge
	* timestamp is to be returned.
	*
	* @return The derived gauge timestamp of the specified object.
	*
	*/
	@Override
	public synchronized long getDerivedGaugeTimeStamp(ObjectName object) {
	return super.getDerivedGaugeTimeStamp(object);
	}

	/**
	* Returns the derived gauge of the first object in the set of
	* observed MBeans.
	*
	* @return The derived gauge.
	*
	* @deprecated As of JMX 1.2, replaced by
	* {@link #getDerivedGauge(ObjectName)}
	*/
	@Deprecated
	public synchronized String getDerivedGauge() {
	if (observedObjects.isEmpty()) {
	return null;
	} else {
	return (String) observedObjects.get(0).getDerivedGauge();
	}
	}

	/**
	* Gets the derived gauge timestamp of the first object in the set
	* of observed MBeans.
	*
	* @return The derived gauge timestamp.
	*
	* @deprecated As of JMX 1.2, replaced by
	* {@link #getDerivedGaugeTimeStamp(ObjectName)}
	*/
	@Deprecated
	public synchronized long getDerivedGaugeTimeStamp() {
	if (observedObjects.isEmpty()) {
	return 0;
	} else {
	return observedObjects.get(0).getDerivedGaugeTimeStamp();
	}
	}

	/**
	* Gets the string to compare with the observed attribute common
	* to all observed MBeans.
	*
	* @return The string value.
	*
	* @see #setStringToCompare
	*/
	public synchronized String getStringToCompare() {
	return stringToCompare;
	}

	/**
	* Sets the string to compare with the observed attribute common
	* to all observed MBeans.
	*
	* @param value The string value.
	*
	* @exception IllegalArgumentException The specified
	* string to compare is null.
	*
	* @see #getStringToCompare
	*/
	public synchronized void setStringToCompare(String value)
	throws IllegalArgumentException {

	if (value == null) {
	throw new IllegalArgumentException("Null string to compare");
	}

	if (stringToCompare.equals(value))
	return;
	stringToCompare = value;

	// Reset values.
	//
	for (ObservedObject o : observedObjects) {
	final StringMonitorObservedObject smo =
	(StringMonitorObservedObject) o;
	smo.setStatus(MATCHING_OR_DIFFERING);
	}
	}

	/**
	* Gets the matching notification's on/off switch value common to
	* all observed MBeans.
	*
	* @return <CODE>true</CODE> if the string monitor notifies when
	* matching the string to compare, <CODE>false</CODE> otherwise.
	*
	* @see #setNotifyMatch
	*/
	public synchronized boolean getNotifyMatch() {
	return notifyMatch;
	}

	/**
	* Sets the matching notification's on/off switch value common to
	* all observed MBeans.
	*
	* @param value The matching notification's on/off switch value.
	*
	* @see #getNotifyMatch
	*/
	public synchronized void setNotifyMatch(boolean value) {
	if (notifyMatch == value)
	return;
	notifyMatch = value;
	}

	/**
	* Gets the differing notification's on/off switch value common to
	* all observed MBeans.
	*
	* @return <CODE>true</CODE> if the string monitor notifies when
	* differing from the string to compare, <CODE>false</CODE> otherwise.
	*
	* @see #setNotifyDiffer
	*/
	public synchronized boolean getNotifyDiffer() {
	return notifyDiffer;
	}

	/**
	* Sets the differing notification's on/off switch value common to
	* all observed MBeans.
	*
	* @param value The differing notification's on/off switch value.
	*
	* @see #getNotifyDiffer
	*/
	public synchronized void setNotifyDiffer(boolean value) {
	if (notifyDiffer == value)
	return;
	notifyDiffer = value;
	}

	/**
	* Returns a <CODE>NotificationInfo</CODE> object containing the name of
	* the Java class of the notification and the notification types sent by
	* the string monitor.
	*/
	@Override
	public MBeanNotificationInfo[] getNotificationInfo() {
	return notifsInfo.clone();
	}

	/*
	* ------------------------------------------
	* PACKAGE METHODS
	* ------------------------------------------
	*/

	/**
	* Factory method for ObservedObject creation.
	*
	* @since 1.6
	*/
	@Override
	ObservedObject createObservedObject(ObjectName object) {
	final StringMonitorObservedObject smo =
	new StringMonitorObservedObject(object);
	smo.setStatus(MATCHING_OR_DIFFERING);
	return smo;
	}

	/**
	* Check that the type of the supplied observed attribute
	* value is one of the value types supported by this monitor.
	*/
	@Override
	synchronized boolean isComparableTypeValid(ObjectName object,
	String attribute,
	Comparable<?> value) {
	// Check that the observed attribute is of type "String".
	//
	if (value instanceof String) {
	return true;
	}
	return false;
	}

	@Override
	synchronized void onErrorNotification(MonitorNotification notification) {
	final StringMonitorObservedObject o = (StringMonitorObservedObject)
	getObservedObject(notification.getObservedObject());
	if (o == null)
	return;

	// Reset values.
	//
	o.setStatus(MATCHING_OR_DIFFERING);
	}

	@Override
	synchronized MonitorNotification buildAlarmNotification(
	ObjectName object,
	String attribute,
	Comparable<?> value) {
	String type = null;
	String msg = null;
	Object trigger = null;

	final StringMonitorObservedObject o =
	(StringMonitorObservedObject) getObservedObject(object);
	if (o == null)
	return null;

	// Send matching notification if notifyMatch is true.
	// Send differing notification if notifyDiffer is true.
	//
	if (o.getStatus() == MATCHING_OR_DIFFERING) {
	if (o.getDerivedGauge().equals(stringToCompare)) {
	if (notifyMatch) {
	type = STRING_TO_COMPARE_VALUE_MATCHED;
	msg = "";
	trigger = stringToCompare;
	}
	o.setStatus(DIFFERING);
	} else {
	if (notifyDiffer) {
	type = STRING_TO_COMPARE_VALUE_DIFFERED;
	msg = "";
	trigger = stringToCompare;
	}
	o.setStatus(MATCHING);
	}
	} else {
	if (o.getStatus() == MATCHING) {
	if (o.getDerivedGauge().equals(stringToCompare)) {
	if (notifyMatch) {
	type = STRING_TO_COMPARE_VALUE_MATCHED;
	msg = "";
	trigger = stringToCompare;
	}
	o.setStatus(DIFFERING);
	}
	} else if (o.getStatus() == DIFFERING) {
	if (!o.getDerivedGauge().equals(stringToCompare)) {
	if (notifyDiffer) {
	type = STRING_TO_COMPARE_VALUE_DIFFERED;
	msg = "";
	trigger = stringToCompare;
	}
	o.setStatus(MATCHING);
	}
	}
	}

	return new MonitorNotification(type,
	this,
	0,
	0,
	msg,
	null,
	null,
	null,
	trigger);
	}
	}

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