18 JMX Connectors
This example provides a sample implementation of how to connect to MBeans and perform
operations on them remotely. The source code contained in this section is used to create
corresponding files in the examples/ directory specified in the
appropriate setup procedure and includes:
-
README file
-
Server
-
SimpleStandardMBean
-
SimpleStandard
-
SimpleDynamic
-
ClientListener
-
Client
examples/Basic/README
#
# Copyright (c) 2004, Oracle and/or its affiliates. All rights reserved.
# ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
#
# ==============================================================================
#
# JMX Tutorial Example
#
# The aim of this example is to show the basic use of the JMX technology. It
# shows the use of standard and dynamic MBeans, and how to perform operations
# locally and remotely, through the RMI connector. In this example both the
# SimpleStandard MBean and the SimpleDynamic MBean expose the same management
# interface.
#
# ==============================================================================
#
# In order to compile and run the example, make a copy of this README file, and
# then simply cut and paste all the commands as needed into a terminal window.
#
# This README makes the assumption that you are running under Java SE 6 on Unix,
# you are familiar with the JMX technology, and with the bourne shell or korn
# shell syntax.
#
# All the commands below are defined using Unix korn shell syntax.
#
# If you are not running Unix and korn shell you are expected to be able to
# adapt these commands to your favorite OS and shell environment.
#
# Compile Java classes
#
# * Server.java: creates an MBeanServer,
# registers a SimpleStandard MBean on the local MBeanServer,
# registers a SimpleDynamic MBean on the local MBeanServer,
# performs local operations on both MBeans,
# creates and starts an RMI connector server (JRMP).
#
# * Client.java: creates an RMI connector (JRMP),
# registers a SimpleStandard MBean on the remote MBeanServer,
# registers a SimpleDynamic MBean on the remote MBeanServer,
# performs remote operations on both MBeans,
# closes the RMI connector.
#
# * ClientListener.java: implements a generic notification listener.
#
# * SimpleStandard.java: implements the Simple standard MBean.
#
# * SimpleStandardMBean.java: the management interface exposed
# by the Simple standard MBean.
#
# * SimpleDynamic.java: implements the Simple dynamic MBean.
#
javac *.java
# Start the RMI registry:
#
rmiregistry 9999 &
# Start the Server (follow the server's execution steps
# until it prompts you to start the
# client on a different shell window)
#
java -classpath . Server
# Start the Client (on a different shell window)
#
java -classpath . Client
# ==============================================================================
examples/Basic/Server.java
/*
* Copyright (c) 2004, Oracle and/or its affiliates. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* - Neither the name of Oracle or the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
* IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
import java.io.IOException;
import javax.management.Attribute;
import javax.management.MBeanAttributeInfo;
import javax.management.MBeanConstructorInfo;
import javax.management.MBeanInfo;
import javax.management.MBeanNotificationInfo;
import javax.management.MBeanOperationInfo;
import javax.management.MBeanServer;
import javax.management.MBeanServerFactory;
import javax.management.ObjectName;
import javax.management.remote.JMXConnectorServer;
import javax.management.remote.JMXConnectorServerFactory;
import javax.management.remote.JMXServiceURL;
public class Server {
public static void main(String[] args) {
try {
// Instantiate the MBean server
//
echo("\n>>> Create the MBean server");
MBeanServer mbs = MBeanServerFactory.createMBeanServer();
waitForEnterPressed();
// Get default domain
//
echo("\n>>> Get the MBean server's default domain");
String domain = mbs.getDefaultDomain();
echo("\tDefault Domain = " + domain);
waitForEnterPressed();
// Create and register the SimpleStandard MBean
//
String mbeanClassName = "SimpleStandard";
String mbeanObjectNameStr =
domain + ":type=" + mbeanClassName + ",name=1";
ObjectName mbeanObjectName =
createSimpleMBean(mbs, mbeanClassName, mbeanObjectNameStr);
waitForEnterPressed();
// Get and display the management information exposed by the
// SimpleStandard MBean
//
printMBeanInfo(mbs, mbeanObjectName, mbeanClassName);
waitForEnterPressed();
// Manage the SimpleStandard MBean
//
manageSimpleMBean(mbs, mbeanObjectName, mbeanClassName);
waitForEnterPressed();
// Create and register the SimpleDynamic MBean
//
mbeanClassName = "SimpleDynamic";
mbeanObjectNameStr =
domain + ":type=" + mbeanClassName + ",name=1";
mbeanObjectName =
createSimpleMBean(mbs, mbeanClassName, mbeanObjectNameStr);
waitForEnterPressed();
// Get and display the management information exposed by the
// SimpleDynamic MBean
//
printMBeanInfo(mbs, mbeanObjectName, mbeanClassName);
waitForEnterPressed();
// Manage the SimpleDynamic MBean
//
manageSimpleMBean(mbs, mbeanObjectName, mbeanClassName);
waitForEnterPressed();
// Create an RMI connector server
//
echo("\nCreate an RMI connector server");
JMXServiceURL url = new JMXServiceURL(
"service:jmx:rmi:///jndi/rmi://localhost:9999/server");
JMXConnectorServer cs =
JMXConnectorServerFactory.newJMXConnectorServer(url, null, mbs);
// Start the RMI connector server
//
echo("\nStart the RMI connector server");
cs.start();
echo("\nThe RMI connector server successfully started");
echo("and is ready to handle incoming connections");
echo("\nStart the client on a different window and");
echo("press <Enter> once the client has finished");
waitForEnterPressed();
// Stop the RMI connector server
//
echo("\nStop the RMI connector server");
cs.stop();
System.out.println("\nBye! Bye!");
} catch (Exception e) {
e.printStackTrace();
}
}
private static ObjectName createSimpleMBean(MBeanServer mbs,
String mbeanClassName,
String mbeanObjectNameStr) {
echo("\n>>> Create the " + mbeanClassName +
" MBean within the MBeanServer");
echo("\tObjectName = " + mbeanObjectNameStr);
try {
ObjectName mbeanObjectName =
ObjectName.getInstance(mbeanObjectNameStr);
mbs.createMBean(mbeanClassName, mbeanObjectName);
return mbeanObjectName;
} catch (Exception e) {
echo("\t!!! Could not create the " + mbeanClassName + " MBean !!!");
e.printStackTrace();
echo("\nEXITING...\n");
System.exit(1);
}
return null;
}
private static void printMBeanInfo(MBeanServer mbs,
ObjectName mbeanObjectName,
String mbeanClassName) {
echo("\n>>> Retrieve the management information for the " +
mbeanClassName);
echo(" MBean using the getMBeanInfo() method of the MBeanServer");
MBeanInfo info = null;
try {
info = mbs.getMBeanInfo(mbeanObjectName);
} catch (Exception e) {
echo("\t!!! Could not get MBeanInfo object for " +
mbeanClassName +" !!!");
e.printStackTrace();
return;
}
echo("\nCLASSNAME: \t" + info.getClassName());
echo("\nDESCRIPTION: \t" + info.getDescription());
echo("\nATTRIBUTES");
MBeanAttributeInfo[] attrInfo = info.getAttributes();
if (attrInfo.length > 0) {
for (int i = 0; i < attrInfo.length; i++) {
echo(" ** NAME: \t" + attrInfo[i].getName());
echo(" DESCR: \t" + attrInfo[i].getDescription());
echo(" TYPE: \t" + attrInfo[i].getType() +
"\tREAD: "+ attrInfo[i].isReadable() +
"\tWRITE: "+ attrInfo[i].isWritable());
}
} else echo(" ** No attributes **");
echo("\nCONSTRUCTORS");
MBeanConstructorInfo[] constrInfo = info.getConstructors();
for (int i=0; i<constrInfo.length; i++) {
echo(" ** NAME: \t" + constrInfo[i].getName());
echo(" DESCR: \t" + constrInfo[i].getDescription());
echo(" PARAM: \t" + constrInfo[i].getSignature().length +
" parameter(s)");
}
echo("\nOPERATIONS");
MBeanOperationInfo[] opInfo = info.getOperations();
if (opInfo.length > 0) {
for (int i = 0; i < opInfo.length; i++) {
echo(" ** NAME: \t" + opInfo[i].getName());
echo(" DESCR: \t" + opInfo[i].getDescription());
echo(" PARAM: \t" + opInfo[i].getSignature().length +
" parameter(s)");
}
} else echo(" ** No operations ** ");
echo("\nNOTIFICATIONS");
MBeanNotificationInfo[] notifInfo = info.getNotifications();
if (notifInfo.length > 0) {
for (int i = 0; i < notifInfo.length; i++) {
echo(" ** NAME: \t" + notifInfo[i].getName());
echo(" DESCR: \t" + notifInfo[i].getDescription());
String notifTypes[] = notifInfo[i].getNotifTypes();
for (int j = 0; j < notifTypes.length; j++) {
echo(" TYPE: \t" + notifTypes[j]);
}
}
} else echo(" ** No notifications **");
}
private static void manageSimpleMBean(MBeanServer mbs,
ObjectName mbeanObjectName,
String mbeanClassName) {
echo("\n>>> Manage the " + mbeanClassName +
" MBean using its attributes ");
echo(" and operations exposed for management");
try {
// Get attribute values
printSimpleAttributes(mbs, mbeanObjectName);
// Change State attribute
echo("\n Setting State attribute to value \"new state\"...");
Attribute stateAttribute = new Attribute("State","new state");
mbs.setAttribute(mbeanObjectName, stateAttribute);
// Get attribute values
printSimpleAttributes(mbs, mbeanObjectName);
// Invoking reset operation
echo("\n Invoking reset operation...");
mbs.invoke(mbeanObjectName, "reset", null, null);
// Get attribute values
printSimpleAttributes(mbs, mbeanObjectName);
} catch (Exception e) {
e.printStackTrace();
}
}
private static void printSimpleAttributes(MBeanServer mbs,
ObjectName mbeanObjectName) {
try {
echo("\n Getting attribute values:");
String State = (String) mbs.getAttribute(mbeanObjectName, "State");
Integer NbChanges =
(Integer) mbs.getAttribute(mbeanObjectName,"NbChanges");
echo("\tState = \"" + State + "\"");
echo("\tNbChanges = " + NbChanges);
} catch (Exception e) {
echo("\t!!! Could not read attributes !!!");
e.printStackTrace();
}
}
private static void echo(String msg) {
System.out.println(msg);
}
private static void sleep(int millis) {
try {
Thread.sleep(millis);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
private static void waitForEnterPressed() {
try {
echo("\nPress <Enter> to continue...");
System.in.read();
} catch (IOException e) {
e.printStackTrace();
}
}
}
examples/Basic/SimpleStandardMBean.java
/*
* Copyright (c) 2004, Oracle and/or its affiliates. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* - Neither the name of Oracle or the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
* IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/**
* This is the management interface explicitly defined for the
* "SimpleStandard" standard MBean.
*
* The "SimpleStandard" standard MBean implements this interface
* in order to be manageable through a JMX agent.
*
* The "SimpleStandardMBean" interface shows how to expose for management:
* - a read/write attribute (named "State") through its getter and setter
* methods,
* - a read-only attribute (named "NbChanges") through its getter method,
* - an operation (named "reset").
*/
public interface SimpleStandardMBean {
/**
* Getter: set the "State" attribute of the "SimpleStandard" standard
* MBean.
*
* @return the current value of the "State" attribute.
*/
public String getState();
/**
* Setter: set the "State" attribute of the "SimpleStandard" standard
* MBean.
*
* @param <VAR>s</VAR> the new value of the "State" attribute.
*/
public void setState(String s);
/**
* Getter: get the "NbChanges" attribute of the "SimpleStandard" standard
* MBean.
*
* @return the current value of the "NbChanges" attribute.
*/
public int getNbChanges();
/**
* Operation: reset to their initial values the "State" and "NbChanges"
* attributes of the "SimpleStandard" standard MBean.
*/
public void reset();
}
examples/Basic/SimpleStandard.java
/*
* Copyright (c) 2004, Oracle and/or its affiliates. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* - Neither the name of Oracle or the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
* IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/**
* Simple definition of a standard MBean, named "SimpleStandard".
*
* The "SimpleStandard" standard MBean shows how to expose attributes
* and operations for management by implementing its corresponding
* "SimpleStandardMBean" management interface.
*
* This MBean has two attributes and one operation exposed
* for management by a JMX agent:
* - the read/write "State" attribute,
* - the read only "NbChanges" attribute,
* - the "reset()" operation.
*
* This object also has one property and one method not exposed
* for management by a JMX agent:
* - the "NbResets" property,
* - the "getNbResets()" method.
*/
import javax.management.AttributeChangeNotification;
import javax.management.MBeanNotificationInfo;
import javax.management.NotificationBroadcasterSupport;
public class SimpleStandard
extends NotificationBroadcasterSupport
implements SimpleStandardMBean {
/*
* -----------------------------------------------------
* CONSTRUCTORS
* -----------------------------------------------------
*/
/* "SimpleStandard" does not provide any specific constructors.
* However, "SimpleStandard" is JMX compliant with regards to
* contructors because the default contructor SimpleStandard()
* provided by the Java compiler is public.
*/
/*
* -----------------------------------------------------
* IMPLEMENTATION OF THE SimpleStandardMBean INTERFACE
* -----------------------------------------------------
*/
/**
* Getter: get the "State" attribute of the "SimpleStandard" standard MBean.
*
* @return the current value of the "State" attribute.
*/
public String getState() {
return state;
}
/**
* Setter: set the "State" attribute of the "SimpleStandard" standard MBean.
*
* @param <VAR>s</VAR> the new value of the "State" attribute.
*/
public void setState(String s) {
state = s;
nbChanges++;
}
/**
* Getter: get the "NbChanges" attribute of the "SimpleStandard" standard
* MBean.
*
* @return the current value of the "NbChanges" attribute.
*/
public int getNbChanges() {
return nbChanges;
}
/**
* Operation: reset to their initial values the "State" and "NbChanges"
* attributes of the "SimpleStandard" standard MBean.
*/
public void reset() {
AttributeChangeNotification acn =
new AttributeChangeNotification(this,
0,
0,
"NbChanges reset",
"NbChanges",
"Integer",
new Integer(nbChanges),
new Integer(0));
state = "initial state";
nbChanges = 0;
nbResets++;
sendNotification(acn);
}
/*
* -----------------------------------------------------
* METHOD NOT EXPOSED FOR MANAGEMENT BY A JMX AGENT
* -----------------------------------------------------
*/
/**
* Return the "NbResets" property.
* This method is not a Getter in the JMX sense because it
* is not exposed in the "SimpleStandardMBean" interface.
*
* @return the current value of the "NbResets" property.
*/
public int getNbResets() {
return nbResets;
}
/**
* Returns an array indicating, for each notification this MBean
* may send, the name of the Java class of the notification and
* the notification type.</p>
*
* @return the array of possible notifications.
*/
public MBeanNotificationInfo[] getNotificationInfo() {
return new MBeanNotificationInfo[] {
new MBeanNotificationInfo(
new String[] { AttributeChangeNotification.ATTRIBUTE_CHANGE },
AttributeChangeNotification.class.getName(),
"This notification is emitted when the reset() method is called.")
};
}
/*
* -----------------------------------------------------
* ATTRIBUTES ACCESSIBLE FOR MANAGEMENT BY A JMX AGENT
* -----------------------------------------------------
*/
private String state = "initial state";
private int nbChanges = 0;
/*
* -----------------------------------------------------
* PROPERTY NOT ACCESSIBLE FOR MANAGEMENT BY A JMX AGENT
* -----------------------------------------------------
*/
private int nbResets = 0;
}
examples/Basic/SimpleDynamic.java
/*
* Copyright (c) 2004, Oracle and/or its affiliates. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* - Neither the name of Oracle or the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
* IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/**
* Simple definition of a dynamic MBean, named "SimpleDynamic".
*
* The "SimpleDynamic" dynamic MBean shows how to expose for management
* attributes and operations, at runtime, by implementing the
* "javax.management.DynamicMBean" interface.
*
* This MBean exposes for management two attributes and one operation:
* - the read/write "State" attribute,
* - the read only "NbChanges" attribute,
* - the "reset()" operation.
* It does so by putting this information in an MBeanInfo object that
* is returned by the getMBeanInfo() method of the DynamicMBean interface.
*
* It implements the access to its attributes through the getAttribute(),
* getAttributes(), setAttribute(), and setAttributes() methods of the
* DynamicMBean interface.
*
* It implements the invocation of its reset() operation through the
* invoke() method of the DynamicMBean interface.
*
* Note that as "SimpleDynamic" explicitly defines one constructor,
* this constructor must be public and exposed for management through
* the MBeanInfo object.
*/
import java.lang.reflect.Constructor;
import java.util.Iterator;
import javax.management.*;
public class SimpleDynamic
extends NotificationBroadcasterSupport
implements DynamicMBean {
/*
* -----------------------------------------------------
* CONSTRUCTORS
* -----------------------------------------------------
*/
public SimpleDynamic() {
// Build the management information to be exposed by the dynamic MBean
//
buildDynamicMBeanInfo();
}
/*
* -----------------------------------------------------
* IMPLEMENTATION OF THE DynamicMBean INTERFACE
* -----------------------------------------------------
*/
/**
* Allows the value of the specified attribute of the Dynamic MBean to be
* obtained.
*/
public Object getAttribute(String attribute_name)
throws AttributeNotFoundException,
MBeanException,
ReflectionException {
// Check attribute_name is not null to avoid NullPointerException
// later on
//
if (attribute_name == null) {
throw new RuntimeOperationsException(
new IllegalArgumentException("Attribute name cannot be null"),
"Cannot invoke a getter of " + dClassName +
" with null attribute name");
}
// Check for a recognized attribute_name and call the corresponding
// getter
//
if (attribute_name.equals("State")) {
return getState();
}
if (attribute_name.equals("NbChanges")) {
return getNbChanges();
}
// If attribute_name has not been recognized throw an
// AttributeNotFoundException
//
throw new AttributeNotFoundException("Cannot find " +
attribute_name +
" attribute in " +
dClassName);
}
/**
* Sets the value of the specified attribute of the Dynamic MBean.
*/
public void setAttribute(Attribute attribute)
throws AttributeNotFoundException,
InvalidAttributeValueException,
MBeanException,
ReflectionException {
// Check attribute is not null to avoid NullPointerException later on
//
if (attribute == null) {
throw new RuntimeOperationsException(
new IllegalArgumentException("Attribute cannot be null"),
"Cannot invoke a setter of " + dClassName +
" with null attribute");
}
String name = attribute.getName();
Object value = attribute.getValue();
if (name == null) {
throw new RuntimeOperationsException(
new IllegalArgumentException("Attribute name cannot be null"),
"Cannot invoke the setter of " + dClassName +
" with null attribute name");
}
// Check for a recognized attribute name and call the corresponding
// setter
//
if (name.equals("State")) {
// if null value, try and see if the setter returns any exception
if (value == null) {
try {
setState( null );
} catch (Exception e) {
throw new InvalidAttributeValueException(
"Cannot set attribute " + name + " to null");
}
}
// if non null value, make sure it is assignable to the attribute
else {
try {
if (Class.forName("java.lang.String").isAssignableFrom(
value.getClass())) {
setState((String) value);
} else {
throw new InvalidAttributeValueException(
"Cannot set attribute " + name + " to a " +
value.getClass().getName() +
" object, String expected");
}
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
}
}
// recognize an attempt to set "NbChanges" attribute (read-only):
else if (name.equals("NbChanges")) {
throw new AttributeNotFoundException(
"Cannot set attribute " + name + " because it is read-only");
}
// unrecognized attribute name:
else {
throw new AttributeNotFoundException("Attribute " + name +
" not found in " +
this.getClass().getName());
}
}
/**
* Enables the to get the values of several attributes of the Dynamic MBean.
*/
public AttributeList getAttributes(String[] attributeNames) {
// Check attributeNames is not null to avoid NullPointerException
// later on
//
if (attributeNames == null) {
throw new RuntimeOperationsException(
new IllegalArgumentException("attributeNames[] cannot be null"),
"Cannot invoke a getter of " + dClassName);
}
AttributeList resultList = new AttributeList();
// If attributeNames is empty, return an empty result list
//
if (attributeNames.length == 0)
return resultList;
// Build the result attribute list
//
for (int i = 0 ; i < attributeNames.length ; i++) {
try {
Object value = getAttribute((String) attributeNames[i]);
resultList.add(new Attribute(attributeNames[i],value));
} catch (Exception e) {
e.printStackTrace();
}
}
return resultList;
}
/**
* Sets the values of several attributes of the Dynamic MBean, and returns
* the list of attributes that have been set.
*/
public AttributeList setAttributes(AttributeList attributes) {
// Check attributes is not null to avoid NullPointerException later on
//
if (attributes == null) {
throw new RuntimeOperationsException(
new IllegalArgumentException(
"AttributeList attributes cannot be null"),
"Cannot invoke a setter of " + dClassName);
}
AttributeList resultList = new AttributeList();
// If attributeNames is empty, nothing more to do
//
if (attributes.isEmpty())
return resultList;
// For each attribute, try to set it and add to the result list if
// successfull
//
for (Iterator i = attributes.iterator(); i.hasNext();) {
Attribute attr = (Attribute) i.next();
try {
setAttribute(attr);
String name = attr.getName();
Object value = getAttribute(name);
resultList.add(new Attribute(name,value));
} catch(Exception e) {
e.printStackTrace();
}
}
return resultList;
}
/**
* Allows an operation to be invoked on the Dynamic MBean.
*/
public Object invoke(String operationName,
Object params[],
String signature[])
throws MBeanException, ReflectionException {
// Check operationName is not null to avoid NullPointerException
// later on
//
if (operationName == null) {
throw new RuntimeOperationsException(
new IllegalArgumentException("Operation name cannot be null"),
"Cannot invoke a null operation in " + dClassName);
}
// Check for a recognized operation name and call the corresponding
// operation
//
if (operationName.equals("reset")) {
reset();
return null;
} else {
// Unrecognized operation name
//
throw new ReflectionException(
new NoSuchMethodException(operationName),
"Cannot find the operation " + operationName +
" in " + dClassName);
}
}
/**
* This method provides the exposed attributes and operations of the
* Dynamic MBean. It provides this information using an MBeanInfo object.
*/
public MBeanInfo getMBeanInfo() {
// Return the information we want to expose for management:
// the dMBeanInfo private field has been built at instanciation time
//
return dMBeanInfo;
}
/*
* -----------------------------------------------------
* OTHER PUBLIC METHODS
* -----------------------------------------------------
*/
/**
* Getter: get the "State" attribute of the "SimpleDynamic" dynamic MBean.
*/
public String getState() {
return state;
}
/**
* Setter: set the "State" attribute of the "SimpleDynamic" dynamic MBean.
*/
public void setState(String s) {
state = s;
nbChanges++;
}
/**
* Getter: get the "NbChanges" attribute of the "SimpleDynamic" dynamic
* MBean.
*/
public Integer getNbChanges() {
return new Integer(nbChanges);
}
/**
* Operation: reset to their initial values the "State" and "NbChanges"
* attributes of the "SimpleDynamic" dynamic MBean.
*/
public void reset() {
AttributeChangeNotification acn =
new AttributeChangeNotification(this,
0,
0,
"NbChanges reset",
"NbChanges",
"Integer",
new Integer(nbChanges),
new Integer(0));
state = "initial state";
nbChanges = 0;
nbResets++;
sendNotification(acn);
}
/**
* Return the "NbResets" property.
* This method is not a Getter in the JMX sense because
* it is not returned by the getMBeanInfo() method.
*/
public Integer getNbResets() {
return new Integer(nbResets);
}
/*
* -----------------------------------------------------
* PRIVATE METHODS
* -----------------------------------------------------
*/
/**
* Build the private dMBeanInfo field,
* which represents the management interface exposed by the MBean,
* that is, the set of attributes, constructors, operations and
* notifications which are available for management.
*
* A reference to the dMBeanInfo object is returned by the getMBeanInfo()
* method of the DynamicMBean interface. Note that, once constructed, an
* MBeanInfo object is immutable.
*/
private void buildDynamicMBeanInfo() {
dAttributes[0] =
new MBeanAttributeInfo("State",
"java.lang.String",
"State string.",
true,
true,
false);
dAttributes[1] =
new MBeanAttributeInfo("NbChanges",
"java.lang.Integer",
"Number of times the " +
"State string has been changed.",
true,
false,
false);
Constructor[] constructors = this.getClass().getConstructors();
dConstructors[0] =
new MBeanConstructorInfo("Constructs a " +
"SimpleDynamic object",
constructors[0]);
MBeanParameterInfo[] params = null;
dOperations[0] =
new MBeanOperationInfo("reset",
"reset State and NbChanges " +
"attributes to their initial values",
params ,
"void",
MBeanOperationInfo.ACTION);
dNotifications[0] =
new MBeanNotificationInfo(
new String[] { AttributeChangeNotification.ATTRIBUTE_CHANGE },
AttributeChangeNotification.class.getName(),
"This notification is emitted when the reset() method is called.");
dMBeanInfo = new MBeanInfo(dClassName,
dDescription,
dAttributes,
dConstructors,
dOperations,
dNotifications);
}
/*
* -----------------------------------------------------
* PRIVATE VARIABLES
* -----------------------------------------------------
*/
private String state = "initial state";
private int nbChanges = 0;
private int nbResets = 0;
private String dClassName = this.getClass().getName();
private String dDescription = "Simple implementation of a dynamic MBean.";
private MBeanAttributeInfo[] dAttributes =
new MBeanAttributeInfo[2];
private MBeanConstructorInfo[] dConstructors =
new MBeanConstructorInfo[1];
private MBeanNotificationInfo[] dNotifications =
new MBeanNotificationInfo[1];
private MBeanOperationInfo[] dOperations =
new MBeanOperationInfo[1];
private MBeanInfo dMBeanInfo = null;
}
examples/Basic/ClientListener.java
/*
* Copyright (c) 2004, Oracle and/or its affiliates. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* - Neither the name of Oracle or the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
* IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
import javax.management.Notification;
import javax.management.NotificationListener;
public class ClientListener implements NotificationListener {
public void handleNotification(Notification notification, Object handback) {
System.out.println("\nReceived notification: " + notification);
}
}
examples/Basic/Client.java
/*
* Copyright (c) 2004, Oracle and/or its affiliates. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* - Neither the name of Oracle or the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
* IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
import java.io.IOException;
import java.util.Iterator;
import java.util.Set;
import javax.management.Attribute;
import javax.management.JMX;
import javax.management.MBeanServerConnection;
import javax.management.ObjectName;
import javax.management.remote.JMXConnector;
import javax.management.remote.JMXConnectorFactory;
import javax.management.remote.JMXServiceURL;
public class Client {
public static void main(String[] args) {
try {
// Create an RMI connector client and
// connect it to the RMI connector server
//
echo("\nCreate an RMI connector client and " +
"connect it to the RMI connector server");
JMXServiceURL url = new JMXServiceURL(
"service:jmx:rmi:///jndi/rmi://localhost:9999/server");
JMXConnector jmxc = JMXConnectorFactory.connect(url, null);
// Create listener
//
ClientListener listener = new ClientListener();
// Get an MBeanServerConnection
//
echo("\nGet an MBeanServerConnection");
MBeanServerConnection mbsc = jmxc.getMBeanServerConnection();
waitForEnterPressed();
// Get domains from MBeanServer
//
echo("\nDomains:");
String domains[] = mbsc.getDomains();
for (int i = 0; i < domains.length; i++) {
echo("\tDomain[" + i + "] = " + domains[i]);
}
waitForEnterPressed();
// Get MBeanServer's default domain
//
String domain = mbsc.getDefaultDomain();
// Create SimpleStandard MBean
//
ObjectName stdMBeanName =
new ObjectName(domain +":type=SimpleStandard,name=2");
echo("\nCreate SimpleStandard MBean...");
mbsc.createMBean("SimpleStandard", stdMBeanName, null, null);
waitForEnterPressed();
// Create SimpleDynamic MBean
//
ObjectName dynMBeanName =
new ObjectName(domain +":type=SimpleDynamic,name=2");
echo("\nCreate SimpleDynamic MBean...");
mbsc.createMBean("SimpleDynamic", dynMBeanName, null, null);
waitForEnterPressed();
// Get MBean count
//
echo("\nMBean count = " + mbsc.getMBeanCount());
// Query MBean names
//
echo("\nQuery MBeanServer MBeans:");
Set names = mbsc.queryNames(null, null);
for (Iterator i = names.iterator(); i.hasNext(); ) {
echo("\tObjectName = " + (ObjectName) i.next());
}
waitForEnterPressed();
// -------------------------------
// Manage the SimpleStandard MBean
// -------------------------------
echo("\n>>> Perform operations on SimpleStandard MBean <<<");
// Get State attribute in SimpleStandard MBean
//
echo("\nState = " + mbsc.getAttribute(stdMBeanName, "State"));
// Set State attribute in SimpleStandard MBean
//
mbsc.setAttribute(stdMBeanName,
new Attribute("State", "changed state"));
// Get State attribute in SimpleStandard MBean
//
// Another way of interacting with a given MBean is through a
// dedicated proxy instead of going directly through the MBean
// server connection
//
SimpleStandardMBean proxy = JMX.newMBeanProxy(
mbsc, stdMBeanName, SimpleStandardMBean.class, true);
echo("\nState = " + proxy.getState());
// Add notification listener on SimpleStandard MBean
//
echo("\nAdd notification listener...");
mbsc.addNotificationListener(stdMBeanName, listener, null, null);
// Invoke "reset" in SimpleStandard MBean
//
// Calling "reset" makes the SimpleStandard MBean emit a
// notification that will be received by the registered
// ClientListener.
//
echo("\nInvoke reset() in SimpleStandard MBean...");
mbsc.invoke(stdMBeanName, "reset", null, null);
// Sleep for 2 seconds in order to have time to receive the
// notification before removing the notification listener.
//
echo("\nWaiting for notification...");
sleep(2000);
// Remove notification listener on SimpleStandard MBean
//
echo("\nRemove notification listener...");
mbsc.removeNotificationListener(stdMBeanName, listener);
// Unregister SimpleStandard MBean
//
echo("\nUnregister SimpleStandard MBean...");
mbsc.unregisterMBean(stdMBeanName);
waitForEnterPressed();
// ------------------------------
// Manage the SimpleDynamic MBean
// ------------------------------
echo("\n>>> Perform operations on SimpleDynamic MBean <<<");
// Get State attribute in SimpleDynamic MBean
//
echo("\nState = " + mbsc.getAttribute(dynMBeanName, "State"));
// Set State attribute in SimpleDynamic MBean
//
mbsc.setAttribute(dynMBeanName,
new Attribute("State", "changed state"));
// Get State attribute in SimpleDynamic MBean
//
echo("\nState = " +
mbsc.getAttribute(dynMBeanName, "State"));
// Add notification listener on SimpleDynamic MBean
//
echo("\nAdd notification listener...");
mbsc.addNotificationListener(dynMBeanName, listener, null, null);
// Invoke "reset" in SimpleDynamic MBean
//
// Calling "reset" makes the SimpleDynamic MBean emit a
// notification that will be received by the registered
// ClientListener.
//
echo("\nInvoke reset() in SimpleDynamic MBean...");
mbsc.invoke(dynMBeanName, "reset", null, null);
// Sleep for 2 seconds in order to have time to receive the
// notification before removing the notification listener.
//
echo("\nWaiting for notification...");
sleep(2000);
// Remove notification listener on SimpleDynamic MBean
//
echo("\nRemove notification listener...");
mbsc.removeNotificationListener(dynMBeanName, listener);
// Unregister SimpleDynamic MBean
//
echo("\nUnregister SimpleDynamic MBean...");
mbsc.unregisterMBean(dynMBeanName);
waitForEnterPressed();
// Close MBeanServer connection
//
echo("\nClose the connection to the server");
jmxc.close();
echo("\nBye! Bye!");
} catch (Exception e) {
e.printStackTrace();
}
}
private static void echo(String msg) {
System.out.println(msg);
}
private static void sleep(int millis) {
try {
Thread.sleep(millis);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
private static void waitForEnterPressed() {
try {
echo("\nPress <Enter> to continue...");
System.in.read();
} catch (IOException e) {
e.printStackTrace();
}
}
}