jdk/src/share/classes/sun/management/DiagnosticCommandImpl.java - edge/openjdk - Git at Google

 /*
  * Copyright (c) 2013, 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 sun.management;

 import com.sun.management.DiagnosticCommandMBean;
 import java.lang.reflect.Constructor;
 import java.lang.reflect.InvocationTargetException;
 import java.security.Permission;
 import java.util.*;
 import javax.management.*;

 /**
  * Implementation class for the diagnostic commands subsystem.
  *
  * @since 8
  */
 class DiagnosticCommandImpl extends NotificationEmitterSupport
     implements DiagnosticCommandMBean {

     private final VMManagement jvm;
     private volatile Map<String, Wrapper> wrappers = null;
     private static final String strClassName = "".getClass().getName();
     private static final String strArrayClassName = String[].class.getName();
     private final boolean isSupported;

     @Override
     public Object getAttribute(String attribute) throws AttributeNotFoundException,
         MBeanException, ReflectionException {
         throw new AttributeNotFoundException(attribute);
     }

     @Override
     public void setAttribute(Attribute attribute) throws AttributeNotFoundException,
         InvalidAttributeValueException, MBeanException, ReflectionException {
         throw new AttributeNotFoundException(attribute.getName());
     }

     @Override
     public AttributeList getAttributes(String[] attributes) {
         return new AttributeList();
     }

     @Override
     public AttributeList setAttributes(AttributeList attributes) {
         return new AttributeList();
     }

     private class Wrapper {

         String name;
         String cmd;
         DiagnosticCommandInfo info;
         Permission permission;

         Wrapper(String name, String cmd, DiagnosticCommandInfo info)
                 throws InstantiationException {
             this.name = name;
             this.cmd = cmd;
             this.info = info;
             this.permission = null;
             Exception cause = null;
             if (info.getPermissionClass() != null) {
                 try {
                     Class c = Class.forName(info.getPermissionClass());
                     if (info.getPermissionAction() == null) {
                         try {
                             Constructor constructor = c.getConstructor(String.class);
                             permission = (Permission) constructor.newInstance(info.getPermissionName());

                         } catch (InstantiationException | IllegalAccessException
                                 | IllegalArgumentException | InvocationTargetException
                                 | NoSuchMethodException | SecurityException ex) {
                             cause = ex;
                         }
                     }
                     if (permission == null) {
                         try {
                             Constructor constructor = c.getConstructor(String.class, String.class);
                             permission = (Permission) constructor.newInstance(
                                     info.getPermissionName(),
                                     info.getPermissionAction());
                         } catch (InstantiationException | IllegalAccessException
                                 | IllegalArgumentException | InvocationTargetException
                                 | NoSuchMethodException | SecurityException ex) {
                             cause = ex;
                         }
                     }
                 } catch (ClassNotFoundException ex) { }
                 if (permission == null) {
                     InstantiationException iex =
                             new InstantiationException("Unable to instantiate required permission");
                     iex.initCause(cause);
                 }
             }
         }

         public String execute(String[] args) {
             if (permission != null) {
                 SecurityManager sm = System.getSecurityManager();
                 if (sm != null) {
                     sm.checkPermission(permission);
                 }
             }
             if(args == null) {
                 return executeDiagnosticCommand(cmd);
             } else {
                 StringBuilder sb = new StringBuilder();
                 sb.append(cmd);
                 for(int i=0; i<args.length; i++) {
                     if(args[i] == null) {
                         throw new IllegalArgumentException("Invalid null argument");
                     }
                     sb.append(" ");
                     sb.append(args[i]);
                 }
                 return executeDiagnosticCommand(sb.toString());
             }
         }
     }

     DiagnosticCommandImpl(VMManagement jvm) {
         this.jvm = jvm;
         isSupported = jvm.isRemoteDiagnosticCommandsSupported();
     }

     private static class OperationInfoComparator implements Comparator<MBeanOperationInfo> {
         @Override
         public int compare(MBeanOperationInfo o1, MBeanOperationInfo o2) {
             return o1.getName().compareTo(o2.getName());
         }
     }

     @Override
     public MBeanInfo getMBeanInfo() {
         SortedSet<MBeanOperationInfo> operations = new TreeSet<>(new OperationInfoComparator());
         Map<String, Wrapper> wrappersmap;
         if (!isSupported) {
             wrappersmap = (Map<String, Wrapper>) Collections.EMPTY_MAP;
         } else {
             try {
                 String[] command = getDiagnosticCommands();
                 DiagnosticCommandInfo[] info = getDiagnosticCommandInfo(command);
                 MBeanParameterInfo stringArgInfo[] = new MBeanParameterInfo[]{
                     new MBeanParameterInfo("arguments", strArrayClassName,
                     "Array of Diagnostic Commands Arguments and Options")
                 };
                 wrappersmap = new HashMap<>();
                 for (int i = 0; i < command.length; i++) {
                     String name = transform(command[i]);
                     try {
                         Wrapper w = new Wrapper(name, command[i], info[i]);
                         wrappersmap.put(name, w);
                         operations.add(new MBeanOperationInfo(
                                 w.name,
                                 w.info.getDescription(),
                                 (w.info.getArgumentsInfo() == null
                                     || w.info.getArgumentsInfo().isEmpty())
                                     ? null : stringArgInfo,
                                 strClassName,
                                 MBeanOperationInfo.ACTION_INFO,
                                 commandDescriptor(w)));
                     } catch (InstantiationException ex) {
                         // If for some reasons the creation of a diagnostic command
                         // wrappers fails, the diagnostic command is just ignored
                         // and won't appear in the DynamicMBean
                     }
                 }
             } catch (IllegalArgumentException | UnsupportedOperationException e) {
                 wrappersmap = (Map<String, Wrapper>) Collections.EMPTY_MAP;
             }
         }
         wrappers =  Collections.unmodifiableMap(wrappersmap);
         HashMap<String, Object> map = new HashMap<>();
         map.put("immutableInfo", "false");
         map.put("interfaceClassName","com.sun.management.DiagnosticCommandMBean");
         map.put("mxbean", "false");
         Descriptor desc = new ImmutableDescriptor(map);
         return new MBeanInfo(
                 this.getClass().getName(),
                 "Diagnostic Commands",
                 null, // attributes
                 null, // constructors
                 operations.toArray(new MBeanOperationInfo[operations.size()]), // operations
                 getNotificationInfo(), // notifications
                 desc);
     }

     @Override
     public Object invoke(String actionName, Object[] params, String[] signature)
             throws MBeanException, ReflectionException {
         if (!isSupported) {
             throw new UnsupportedOperationException();
         }
         if (wrappers == null) {
             getMBeanInfo();
         }
         Wrapper w = wrappers.get(actionName);
         if (w != null) {
             if (w.info.getArgumentsInfo().isEmpty()
                     && (params == null || params.length == 0)
                     && (signature == null || signature.length == 0)) {
                 return w.execute(null);
             } else if((params != null && params.length == 1)
                     && (signature != null && signature.length == 1
                     && signature[0] != null
                     && signature[0].compareTo(strArrayClassName) == 0)) {
                 return w.execute((String[]) params[0]);
             }
         }
         throw new ReflectionException(new NoSuchMethodException(actionName));
     }

     private static String transform(String name) {
         StringBuilder sb = new StringBuilder();
         boolean toLower = true;
         boolean toUpper = false;
         for (int i = 0; i < name.length(); i++) {
             char c = name.charAt(i);
             if (c == '.' || c == '_') {
                 toLower = false;
                 toUpper = true;
             } else {
                 if (toUpper) {
                     toUpper = false;
                     sb.append(Character.toUpperCase(c));
                 } else if(toLower) {
                     sb.append(Character.toLowerCase(c));
                 } else {
                     sb.append(c);
                 }
             }
         }
         return sb.toString();
     }

     private Descriptor commandDescriptor(Wrapper w) throws IllegalArgumentException {
         HashMap<String, Object> map = new HashMap<>();
         map.put("dcmd.name", w.info.getName());
         map.put("dcmd.description", w.info.getDescription());
         map.put("dcmd.vmImpact", w.info.getImpact());
         map.put("dcmd.permissionClass", w.info.getPermissionClass());
         map.put("dcmd.permissionName", w.info.getPermissionName());
         map.put("dcmd.permissionAction", w.info.getPermissionAction());
         map.put("dcmd.enabled", w.info.isEnabled());
         StringBuilder sb = new StringBuilder();
         sb.append("help ");
         sb.append(w.info.getName());
         map.put("dcmd.help", executeDiagnosticCommand(sb.toString()));
         if (w.info.getArgumentsInfo() != null && !w.info.getArgumentsInfo().isEmpty()) {
             HashMap<String, Object> allargmap = new HashMap<>();
             for (DiagnosticCommandArgumentInfo arginfo : w.info.getArgumentsInfo()) {
                 HashMap<String, Object> argmap = new HashMap<>();
                 argmap.put("dcmd.arg.name", arginfo.getName());
                 argmap.put("dcmd.arg.type", arginfo.getType());
                 argmap.put("dcmd.arg.description", arginfo.getDescription());
                 argmap.put("dcmd.arg.isMandatory", arginfo.isMandatory());
                 argmap.put("dcmd.arg.isMultiple", arginfo.isMultiple());
                 boolean isOption = arginfo.isOption();
                 argmap.put("dcmd.arg.isOption", isOption);
                 if(!isOption) {
                     argmap.put("dcmd.arg.position", arginfo.getPosition());
                 } else {
                     argmap.put("dcmd.arg.position", -1);
                 }
                 allargmap.put(arginfo.getName(), new ImmutableDescriptor(argmap));
             }
             map.put("dcmd.arguments", new ImmutableDescriptor(allargmap));
         }
         return new ImmutableDescriptor(map);
     }

     private final static String notifName =
         "javax.management.Notification";

     private final static String[] diagFramNotifTypes = {
         "jmx.mbean.info.changed"
     };

     private MBeanNotificationInfo[] notifInfo = null;

     @Override
     public MBeanNotificationInfo[] getNotificationInfo() {
         synchronized (this) {
             if (notifInfo == null) {
                  notifInfo = new MBeanNotificationInfo[1];
                  notifInfo[0] =
                          new MBeanNotificationInfo(diagFramNotifTypes,
                                                    notifName,
                                                    "Diagnostic Framework Notification");
             }
         }
         return notifInfo;
     }

     private static long seqNumber = 0;
     private static long getNextSeqNumber() {
         return ++seqNumber;
     }

     private void createDiagnosticFrameworkNotification() {

         if (!hasListeners()) {
             return;
         }
         ObjectName on = null;
         try {
             on = ObjectName.getInstance(ManagementFactoryHelper.HOTSPOT_DIAGNOSTIC_COMMAND_MBEAN_NAME);
         } catch (MalformedObjectNameException e) { }
         Notification notif = new Notification("jmx.mbean.info.changed",
                                               on,
                                               getNextSeqNumber());
         notif.setUserData(getMBeanInfo());
         sendNotification(notif);
     }

     @Override
     public synchronized void addNotificationListener(NotificationListener listener,
             NotificationFilter filter,
             Object handback) {
         boolean before = hasListeners();
         super.addNotificationListener(listener, filter, handback);
         boolean after = hasListeners();
         if (!before && after) {
             setNotificationEnabled(true);
         }
     }

     @Override
     public synchronized void removeNotificationListener(NotificationListener listener)
             throws ListenerNotFoundException {
         boolean before = hasListeners();
         super.removeNotificationListener(listener);
         boolean after = hasListeners();
         if (before && !after) {
             setNotificationEnabled(false);
         }
     }

     @Override
     public synchronized void removeNotificationListener(NotificationListener listener,
             NotificationFilter filter,
             Object handback)
             throws ListenerNotFoundException {
         boolean before = hasListeners();
         super.removeNotificationListener(listener, filter, handback);
         boolean after = hasListeners();
         if (before && !after) {
             setNotificationEnabled(false);
         }
     }

     private native void setNotificationEnabled(boolean enabled);
     private native String[] getDiagnosticCommands();
     private native DiagnosticCommandInfo[] getDiagnosticCommandInfo(String[] commands);
     private native String executeDiagnosticCommand(String command);

 }
	/*
	* Copyright (c) 2013, 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 sun.management;

	import com.sun.management.DiagnosticCommandMBean;
	import java.lang.reflect.Constructor;
	import java.lang.reflect.InvocationTargetException;
	import java.security.Permission;
	import java.util.*;
	import javax.management.*;

	/**
	* Implementation class for the diagnostic commands subsystem.
	*
	* @since 8
	*/
	class DiagnosticCommandImpl extends NotificationEmitterSupport
	implements DiagnosticCommandMBean {

	private final VMManagement jvm;
	private volatile Map<String, Wrapper> wrappers = null;
	private static final String strClassName = "".getClass().getName();
	private static final String strArrayClassName = String[].class.getName();
	private final boolean isSupported;

	@Override
	public Object getAttribute(String attribute) throws AttributeNotFoundException,
	MBeanException, ReflectionException {
	throw new AttributeNotFoundException(attribute);
	}

	@Override
	public void setAttribute(Attribute attribute) throws AttributeNotFoundException,
	InvalidAttributeValueException, MBeanException, ReflectionException {
	throw new AttributeNotFoundException(attribute.getName());
	}

	@Override
	public AttributeList getAttributes(String[] attributes) {
	return new AttributeList();
	}

	@Override
	public AttributeList setAttributes(AttributeList attributes) {
	return new AttributeList();
	}

	private class Wrapper {

	String name;
	String cmd;
	DiagnosticCommandInfo info;
	Permission permission;

	Wrapper(String name, String cmd, DiagnosticCommandInfo info)
	throws InstantiationException {
	this.name = name;
	this.cmd = cmd;
	this.info = info;
	this.permission = null;
	Exception cause = null;
	if (info.getPermissionClass() != null) {
	try {
	Class c = Class.forName(info.getPermissionClass());
	if (info.getPermissionAction() == null) {
	try {
	Constructor constructor = c.getConstructor(String.class);
	permission = (Permission) constructor.newInstance(info.getPermissionName());

	} catch (InstantiationException \| IllegalAccessException
	\| IllegalArgumentException \| InvocationTargetException
	\| NoSuchMethodException \| SecurityException ex) {
	cause = ex;
	}
	}
	if (permission == null) {
	try {
	Constructor constructor = c.getConstructor(String.class, String.class);
	permission = (Permission) constructor.newInstance(
	info.getPermissionName(),
	info.getPermissionAction());
	} catch (InstantiationException \| IllegalAccessException
	\| IllegalArgumentException \| InvocationTargetException
	\| NoSuchMethodException \| SecurityException ex) {
	cause = ex;
	}
	}
	} catch (ClassNotFoundException ex) { }
	if (permission == null) {
	InstantiationException iex =
	new InstantiationException("Unable to instantiate required permission");
	iex.initCause(cause);
	}
	}
	}

	public String execute(String[] args) {
	if (permission != null) {
	SecurityManager sm = System.getSecurityManager();
	if (sm != null) {
	sm.checkPermission(permission);
	}
	}
	if(args == null) {
	return executeDiagnosticCommand(cmd);
	} else {
	StringBuilder sb = new StringBuilder();
	sb.append(cmd);
	for(int i=0; i<args.length; i++) {
	if(args[i] == null) {
	throw new IllegalArgumentException("Invalid null argument");
	}
	sb.append(" ");
	sb.append(args[i]);
	}
	return executeDiagnosticCommand(sb.toString());
	}
	}
	}

	DiagnosticCommandImpl(VMManagement jvm) {
	this.jvm = jvm;
	isSupported = jvm.isRemoteDiagnosticCommandsSupported();
	}

	private static class OperationInfoComparator implements Comparator<MBeanOperationInfo> {
	@Override
	public int compare(MBeanOperationInfo o1, MBeanOperationInfo o2) {
	return o1.getName().compareTo(o2.getName());
	}
	}

	@Override
	public MBeanInfo getMBeanInfo() {
	SortedSet<MBeanOperationInfo> operations = new TreeSet<>(new OperationInfoComparator());
	Map<String, Wrapper> wrappersmap;
	if (!isSupported) {
	wrappersmap = (Map<String, Wrapper>) Collections.EMPTY_MAP;
	} else {
	try {
	String[] command = getDiagnosticCommands();
	DiagnosticCommandInfo[] info = getDiagnosticCommandInfo(command);
	MBeanParameterInfo stringArgInfo[] = new MBeanParameterInfo[]{
	new MBeanParameterInfo("arguments", strArrayClassName,
	"Array of Diagnostic Commands Arguments and Options")
	};
	wrappersmap = new HashMap<>();
	for (int i = 0; i < command.length; i++) {
	String name = transform(command[i]);
	try {
	Wrapper w = new Wrapper(name, command[i], info[i]);
	wrappersmap.put(name, w);
	operations.add(new MBeanOperationInfo(
	w.name,
	w.info.getDescription(),
	(w.info.getArgumentsInfo() == null
	\|\| w.info.getArgumentsInfo().isEmpty())
	? null : stringArgInfo,
	strClassName,
	MBeanOperationInfo.ACTION_INFO,
	commandDescriptor(w)));
	} catch (InstantiationException ex) {
	// If for some reasons the creation of a diagnostic command
	// wrappers fails, the diagnostic command is just ignored
	// and won't appear in the DynamicMBean
	}
	}
	} catch (IllegalArgumentException \| UnsupportedOperationException e) {
	wrappersmap = (Map<String, Wrapper>) Collections.EMPTY_MAP;
	}
	}
	wrappers = Collections.unmodifiableMap(wrappersmap);
	HashMap<String, Object> map = new HashMap<>();
	map.put("immutableInfo", "false");
	map.put("interfaceClassName","com.sun.management.DiagnosticCommandMBean");
	map.put("mxbean", "false");
	Descriptor desc = new ImmutableDescriptor(map);
	return new MBeanInfo(
	this.getClass().getName(),
	"Diagnostic Commands",
	null, // attributes
	null, // constructors
	operations.toArray(new MBeanOperationInfo[operations.size()]), // operations
	getNotificationInfo(), // notifications
	desc);
	}

	@Override
	public Object invoke(String actionName, Object[] params, String[] signature)
	throws MBeanException, ReflectionException {
	if (!isSupported) {
	throw new UnsupportedOperationException();
	}
	if (wrappers == null) {
	getMBeanInfo();
	}
	Wrapper w = wrappers.get(actionName);
	if (w != null) {
	if (w.info.getArgumentsInfo().isEmpty()
	&& (params == null \|\| params.length == 0)
	&& (signature == null \|\| signature.length == 0)) {
	return w.execute(null);
	} else if((params != null && params.length == 1)
	&& (signature != null && signature.length == 1
	&& signature[0] != null
	&& signature[0].compareTo(strArrayClassName) == 0)) {
	return w.execute((String[]) params[0]);
	}
	}
	throw new ReflectionException(new NoSuchMethodException(actionName));
	}

	private static String transform(String name) {
	StringBuilder sb = new StringBuilder();
	boolean toLower = true;
	boolean toUpper = false;
	for (int i = 0; i < name.length(); i++) {
	char c = name.charAt(i);
	if (c == '.' \|\| c == '_') {
	toLower = false;
	toUpper = true;
	} else {
	if (toUpper) {
	toUpper = false;
	sb.append(Character.toUpperCase(c));
	} else if(toLower) {
	sb.append(Character.toLowerCase(c));
	} else {
	sb.append(c);
	}
	}
	}
	return sb.toString();
	}

	private Descriptor commandDescriptor(Wrapper w) throws IllegalArgumentException {
	HashMap<String, Object> map = new HashMap<>();
	map.put("dcmd.name", w.info.getName());
	map.put("dcmd.description", w.info.getDescription());
	map.put("dcmd.vmImpact", w.info.getImpact());
	map.put("dcmd.permissionClass", w.info.getPermissionClass());
	map.put("dcmd.permissionName", w.info.getPermissionName());
	map.put("dcmd.permissionAction", w.info.getPermissionAction());
	map.put("dcmd.enabled", w.info.isEnabled());
	StringBuilder sb = new StringBuilder();
	sb.append("help ");
	sb.append(w.info.getName());
	map.put("dcmd.help", executeDiagnosticCommand(sb.toString()));
	if (w.info.getArgumentsInfo() != null && !w.info.getArgumentsInfo().isEmpty()) {
	HashMap<String, Object> allargmap = new HashMap<>();
	for (DiagnosticCommandArgumentInfo arginfo : w.info.getArgumentsInfo()) {
	HashMap<String, Object> argmap = new HashMap<>();
	argmap.put("dcmd.arg.name", arginfo.getName());
	argmap.put("dcmd.arg.type", arginfo.getType());
	argmap.put("dcmd.arg.description", arginfo.getDescription());
	argmap.put("dcmd.arg.isMandatory", arginfo.isMandatory());
	argmap.put("dcmd.arg.isMultiple", arginfo.isMultiple());
	boolean isOption = arginfo.isOption();
	argmap.put("dcmd.arg.isOption", isOption);
	if(!isOption) {
	argmap.put("dcmd.arg.position", arginfo.getPosition());
	} else {
	argmap.put("dcmd.arg.position", -1);
	}
	allargmap.put(arginfo.getName(), new ImmutableDescriptor(argmap));
	}
	map.put("dcmd.arguments", new ImmutableDescriptor(allargmap));
	}
	return new ImmutableDescriptor(map);
	}

	private final static String notifName =
	"javax.management.Notification";

	private final static String[] diagFramNotifTypes = {
	"jmx.mbean.info.changed"
	};

	private MBeanNotificationInfo[] notifInfo = null;

	@Override
	public MBeanNotificationInfo[] getNotificationInfo() {
	synchronized (this) {
	if (notifInfo == null) {
	notifInfo = new MBeanNotificationInfo[1];
	notifInfo[0] =
	new MBeanNotificationInfo(diagFramNotifTypes,
	notifName,
	"Diagnostic Framework Notification");
	}
	}
	return notifInfo;
	}

	private static long seqNumber = 0;
	private static long getNextSeqNumber() {
	return ++seqNumber;
	}

	private void createDiagnosticFrameworkNotification() {

	if (!hasListeners()) {
	return;
	}
	ObjectName on = null;
	try {
	on = ObjectName.getInstance(ManagementFactoryHelper.HOTSPOT_DIAGNOSTIC_COMMAND_MBEAN_NAME);
	} catch (MalformedObjectNameException e) { }
	Notification notif = new Notification("jmx.mbean.info.changed",
	on,
	getNextSeqNumber());
	notif.setUserData(getMBeanInfo());
	sendNotification(notif);
	}

	@Override
	public synchronized void addNotificationListener(NotificationListener listener,
	NotificationFilter filter,
	Object handback) {
	boolean before = hasListeners();
	super.addNotificationListener(listener, filter, handback);
	boolean after = hasListeners();
	if (!before && after) {
	setNotificationEnabled(true);
	}
	}

	@Override
	public synchronized void removeNotificationListener(NotificationListener listener)
	throws ListenerNotFoundException {
	boolean before = hasListeners();
	super.removeNotificationListener(listener);
	boolean after = hasListeners();
	if (before && !after) {
	setNotificationEnabled(false);
	}
	}

	@Override
	public synchronized void removeNotificationListener(NotificationListener listener,
	NotificationFilter filter,
	Object handback)
	throws ListenerNotFoundException {
	boolean before = hasListeners();
	super.removeNotificationListener(listener, filter, handback);
	boolean after = hasListeners();
	if (before && !after) {
	setNotificationEnabled(false);
	}
	}

	private native void setNotificationEnabled(boolean enabled);
	private native String[] getDiagnosticCommands();
	private native DiagnosticCommandInfo[] getDiagnosticCommandInfo(String[] commands);
	private native String executeDiagnosticCommand(String command);

	}