So the MBean we want to access is as follows:
oc4j:j2eeType=JVM,name=single,J2EEServer=standalone
And the statistics we want to display which ASC shows for us are as follows:
- FreeHeapSize
- ActiveThreads
- HeapSize
package oracle.support.oc4j.standalone;
import java.text.DateFormat;
import java.util.Date;
import java.util.logging.Logger;
import javax.management.MBeanServerConnection;
import javax.management.ObjectName;
import javax.management.j2ee.statistics.JVMStats;
import javax.management.j2ee.statistics.Statistic;
import javax.management.j2ee.statistics.BoundedRangeStatistic;
public class JVMMonitor implements Runnable
{
private final Logger logger = Logger.getLogger(this.getClass().getName());
private static final DateFormat DATEFORMAT = DateFormat.getInstance();
private OC4JConnection con = null;
private MBeanServerConnection mbs = null;
private String targetMBean = "oc4j:j2eeType=JVM,name=single,J2EEServer=standalone";
private ObjectName mbean = null;
public JVMMonitor() throws Exception
{
// retrieve an OC4JConnection object this is a singleton class
con = OC4JConnection.getInstance();
mbs = con.getConnection();
mbean = new ObjectName(targetMBean);
System.out.println("** JVM Details **");
System.out.printf("Opmn Managed: %s\n",
mbs.getAttribute(mbean, "opmnEnabled"));
System.out.printf("Java Version: %s\n",
mbs.getAttribute(mbean, "javaVersion"));
System.out.printf("Java Vendor: %s\n",
mbs.getAttribute(mbean, "javaVendor"));
System.out.printf("Host Node: %s\n",
mbs.getAttribute(mbean, "node"));
System.out.printf("RMI Port: %s\n",
mbs.getAttribute(mbean, "rmiPort"));
System.out.printf("RMIS Port: %s\n",
mbs.getAttribute(mbean, "rmisPort"));
System.out.printf("RMI IP: %s\n",
mbs.getAttribute(mbean, "rmiServerAddress"));
}
public void run ()
{
System.out.println("\n");
try
{
System.out.printf("--> Current JVM Details [%s]\n\n",
DATEFORMAT.format(new Date()));
showStats(mbean);
System.out.printf("\n<-- End...\n");
}
catch (Exception e)
{
System.out.println("Error in run()");
e.printStackTrace();
}
finally
{
//con.close();
}
}
private void showStats(ObjectName cp) throws Exception
{
JVMStats stats =
(JVMStats) mbs.getAttribute(cp, "stats");
Object mem = null;
mem = mbs.getAttribute(cp, "totalMemory");
Long memLong = null;
memLong = (Long) mem;
System.out.printf("Total Memory: %s\n", memLong.intValue()/1024/1024 + "M");
mem = mbs.getAttribute(cp, "freeMemory");
memLong = (Long) mem;
System.out.printf("Free Memory: %s\n",
memLong.intValue()/1024/1024 + "M");
System.out.printf("HeapSize: %s\n",
stats.getHeapSize().getCurrent()/1024 + "M");
System.out.printf("HighWaterMark: %s\n",
stats.getHeapSize().getHighWaterMark()/1024 + "M");
System.out.printf("LowWaterMark: %s\n",
stats.getHeapSize().getLowWaterMark()/1024 + "M");
Statistic[] allStats = stats.getStatistics();
for (Statistic s: allStats)
{
if (!s.getName().equalsIgnoreCase("UpTime"))
{
System.out.println("\n--");
System.out.printf("JVM Statistic [%s]\n", s.getName());
System.out.printf("Description : %s\n", s.getDescription());
System.out.printf("Unit : %s\n", s.getUnit());
System.out.printf("Last Sample Time : %s\n", new Date(s.getLastSampleTime()));
BoundedRangeStatistic brs = (BoundedRangeStatistic) s;
if (s.getUnit().equals("THREADS"))
{
System.out.printf("High WaterMark : %s\n", brs.getHighWaterMark());
System.out.printf("Low WaterMark : %s\n", brs.getLowWaterMark());
System.out.printf("Current : %s\n", brs.getCurrent());
}
else
{
System.out.printf("High WaterMark : %s\n", brs.getHighWaterMark()/1024 + "M");
System.out.printf("Low WaterMark : %s\n", brs.getLowWaterMark()/1024 + "M");
System.out.printf("Current : %s\n", brs.getCurrent()/1024 + "M");
}
}
}
}
}
So the output would then be as follows:
** JVM Details **
Opmn Managed: true
Java Version: 1.5.0_06
Java Vendor: Sun Microsystems Inc.
Host Node: beast.au.oracle.com
RMI Port: 12406
RMIS Port: 12706
RMI IP: 10.187.80.70
JVMMonitor
Period to report results in seconds is : 5
** Started [4/09/08 11:29] with 5(sec) interval between reports **
--> Current JVM Details [4/09/08 11:29]
Total Memory: 515M
Free Memory: 453M
HeapSize: 515M
HighWaterMark: 550M
LowWaterMark: 504M
--
JVM Statistic [FreeHeapSize]
Description : The amount of free heap memory
Unit : KILO BYTES
Last Sample Time : Thu Sep 04 11:06:44 EST 2008
High WaterMark : 515M
Low WaterMark : 433M
Current : 453M
--
JVM Statistic [ActiveThreads]
Description : The number of active thread(s)
Unit : THREADS
Last Sample Time : Thu Sep 04 11:06:44 EST 2008
High WaterMark : 64
Low WaterMark : 4
Current : 64
--
JVM Statistic [HeapSize]
Description : The size of the JVM's heap
Unit : KILO BYTES
Last Sample Time : Thu Sep 04 11:06:44 EST 2008
High WaterMark : 550M
Low WaterMark : 504M
Current : 515M
<-- End...
Few people asked for this class itself.
OC4JConnection.java
package oracle.support.oc4j.standalone;
import java.io.FileInputStream;
import java.util.Hashtable;
import java.util.Properties;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.management.MBeanServerConnection;
import javax.management.remote.JMXConnector;
import javax.management.remote.JMXConnectorFactory;
import javax.management.remote.JMXServiceURL;
import oracle.oc4j.admin.jmx.remote.api.JMXConnectorConstant;
public class OC4JConnection
{
private static Properties myProperties = new Properties();
private JMXConnector jmxCon = null;
private static OC4JConnection instance = null;
private final Logger logger = Logger.getLogger(this.getClass().getName());
private String username = null;
private String password = null;
private String url = null;
private OC4JConnection
(Properties inProps) throws Exception
{
try
{
processProps(inProps);
logger.log
(Level.INFO, "Username = " + username);
logger.log
(Level.INFO, "Service URL = " + url);
// Define the connection target
JMXServiceURL serviceUrl = new JMXServiceURL(url);
Hashtable env = new Hashtable();
env.put(JMXConnectorFactory.PROTOCOL_PROVIDER_PACKAGES,
"oracle.oc4j.admin.jmx.remote");
Hashtable credentials = new Hashtable();
credentials.put
(JMXConnectorConstant.CREDENTIALS_LOGIN_KEY, username);
credentials.put(JMXConnectorConstant.CREDENTIALS_PASSWORD_KEY,
password);
env.put(JMXConnector.CREDENTIALS, credentials);
jmxCon = JMXConnectorFactory.newJMXConnector(serviceUrl, env);
// Connect to the target OC4J instance defined in the JMXServiceURL
jmxCon.connect();
logger.log
(Level.INFO, "Connected to OC4J");
}
catch (Exception e)
{
logger.log
(Level.SEVERE,
"** [OC4JConnection()] : Unable to obtain Stand Alone Connection",
e);
e.printStackTrace();
}
}
public static OC4JConnection getInstance() throws Exception
{
if(instance == null)
{
myProperties.load(new FileInputStream("build.properties"));
instance = new OC4JConnection(myProperties);
}
return instance;
}
private void processProps(Properties inProps)
{
username = inProps.getProperty("username");
password = inProps.getProperty("password");
url = inProps.getProperty("serviceurl");
}
public MBeanServerConnection getConnection ()
{
MBeanServerConnection mbs = null;
if (jmxCon != null)
{
try
{
mbs = jmxCon.getMBeanServerConnection();
}
catch (Throwable t)
{
logger.log
(Level.SEVERE,
"**[getConnection] : Unable to retrieve MBeanServerConnection");
}
}
return mbs;
}
/**
* Determine if the client is currently connected
* @return true if connected
*/
public boolean isConnected ()
{
boolean ret = false;
if (jmxCon == null)
{
return false;
}
else
{
try
{
jmxCon.getConnectionId();
return true;
}
catch (Throwable t)
{
//
}
}
return ret;
}
/**
* Close the JMXConnector.
*/
public void close ()
{
if (jmxCon != null)
{
try
{
jmxCon.close();
jmxCon = null;
logger.log
(Level.INFO, "Closed Connection to OC4J");
}
catch (Throwable t)
{
}
}
}
}
