com.adventnet.snmp.beans
Class SnmpPoller

java.lang.Object
  |
  +--com.adventnet.snmp.beans.SnmpServer
        |
        +--com.adventnet.snmp.beans.SnmpTarget
              |
              +--com.adventnet.snmp.beans.SnmpPoller

All Implemented Interfaces:

CustomizerTemplate, java.util.EventListener, java.lang.Runnable, java.io.Serializable, java.beans.VetoableChangeListener

public class SnmpPoller

extends SnmpTarget

implements java.lang.Runnable, java.beans.VetoableChangeListener

This class is an SNMP Poller bean for automatic polling of one or more variables from a given remote agent. After each poll, it generates events, i.e. ResultEvent objects, for which listeners can be registered.It can be used with bean builders and other applications, where you can set up SNMP polling and automatic updates.

The SnmpPoller bean is a sub-class of the SnmpTarget bean. It uses SnmpTarget for polling the data. The class using SnmpPoller should instantiate SnmpPoller and set up the properties like hostname, port, version, community of the agent, etc., to match the agent that needs to be queried. Set the ObjectID to be polled and add one or more listeners for receiving the polled data. The result data can also be plotted in Graph (LineGraph or BarGraph).

	SnmpPoller poller = new SnmpPoller(); // Instantiate SnmpPoller.  
	poller.setObjectID("1.3.0");  //the OID to be polled  
	poller.setTargetHost("localhost"); //the host name or IP address of the machine.  
	poller.setPollInterval(10); //polling interval in seconds. Default is 5 seconds.
	poller.setSendTimeoutEvents(true);  // to receive timeout events. 
	ResultAdapter listener = new ResultAdapter() { 
 		public void setResult(ResultEvent evt) { 
			if(evt.isSuccess())	{
				System.err.println("SnmpPoller Response: "+evt.getValue(0)); 
			}
			else	{
				System.out.println("Error String : " + evt.getErrorString());
			}
		} 
	}; 
	poller.addResultListener(listener);
 

In some cases it may be required that the poller should not start polling automatically. To achieve this:

 	poller.setAutoActive(false); //to avoid polling getting started automatically
 

Now the poller will not start polling automatically. To start polling the data:

	poller.restartPolling(); //to start polling the SNMP data.
 

For polling multiple OIDs,

	 poller.setObjectIDList(oids); 
	ResultListener listener = new ResultListener() { 
		public void setResult(ResultEvent evt) { 
			if(evt.isSuccess())	{
				System.out.println("SnmpPoller Response: ");
				for(int i=0;i
 

 Different SnmpPoller instances on the same JVM, will reuse the SnmpAPI, 
 SnmpSession and MibOperations instance. So, for releasing these resources, 
 releaseResources() method should be called on every SnmpPoller instance 
 created and when this method is called on the final instance of SnmpPoller, 
 these will be garbage collected.
 

 See the superclass SnmpTarget, for details on parameters
 and more on methods for setting up the poller parameters.




See Also:
SnmpTarget, 
ResultEvent, 
ResultListener, 
Serialized Form









Field Summary

 
Fields inherited from class com.adventnet.snmp.beans.SnmpTarget
serialize, SNMPGET, SNMPGETBULK, SNMPGETNEXT, SNMPINFORM, SNMPREPORT, SNMPRESPONSE, SNMPSET, SNMPTRAP, SNMPV2TRAP, VERSION1, VERSION2C, VERSION3
 
Fields inherited from class com.adventnet.snmp.beans.SnmpServer
AUTH_NO_PRIV, AUTH_PRIV, CBC_3DES, CBC_DES, CFB_AES_128, CFB_AES_192, CFB_AES_256, MD5_AUTH, NO_AUTH, NO_AUTH_NO_PRIV, NO_PRIV, oidList, SHA_AUTH
 



Constructor Summary
SnmpPoller()



          This constructor is used for polling data applications.
SnmpPoller(java.applet.Applet applet)



          This constructor is used for applets.
SnmpPoller(int protocol,
           ProtocolOptions options)



          This constructor is used for applications which use protocols
 other than UDP/IP.
 



Method Summary




 void
addResultListener(ResultListener l)



          add a listener for events from this poller.



protected  void
finalize()



          this cleans up if no one is using



protected  void
genEvent(SnmpPDU pdu)



          generate the events to the listeners



 boolean
getAbsoluteCounters()



          To get whether the value returned by the poller will be the absolute value or 
 the difference between successive counters.



 boolean
getPollingStatus()



          returns whether the polling of some data is going on or not.



 int
getPollInterval()



          get the current polling interval in seconds



 boolean
isAutoActive()



          returns whether the poller will be started automatically i.e.



 void
pausePolling()



          stops the polling.



 void
removeResultListener(ResultListener l)



          Remove a listener for events from this poller.



 void
restartPolling()



          Restart the SNMP polling.



 void
run()



          the work done by the polling thread.



 void
setAbsoluteCounters(boolean absoluteCounters)



          sets whether counter values should be absolute - applies only for single
 variable requests.



 void
setAutoActive(boolean isAutoActive)



          To make the poller to start polling automatically after setting either OID or
 poll interval or after adding the first result listener.



 void
setObjectID(int index,
            java.lang.String s)



          Set the object ID value at index based on specified string



 void
setObjectID(java.lang.String s)



          Set the object ID specified by the String value.



 void
setObjectIDList(java.lang.String[] s)



          Set the list of object IDs  based on the specified string array.



 void
setPollInterval(int i)



          set the polling interval in seconds



 void
stopPolling()



          Stop the polling and Stops the thread - disables the data collection from 
 the agent and event generation.



 void
vetoableChange(java.beans.PropertyChangeEvent evt)



          Sets the properties constrained properties.


 
Methods inherited from class com.adventnet.snmp.beans.SnmpTarget
addLogClient, addLogClient, addObjectID, addSnmpOID, addSnmpPropertyListener, addUserError, addV3HandShakeResultListener, enableDebugForPDU, genTimeoutEvent, getAttemptComplete, getAttemptPartial, getAuthPassword, getAuthProtocol, getCommunity, getCompleteResponse, getContextID, getContextName, getDebug, getEngineID, getErrorCode, getErrorCodes, getErrorIndex, getErrorString, getExceptionCode, getExceptionCodes, getIgnoreSpecificControlCodes, getMaxNumRows, getMaxRepetitions, getMibModules, getMibOperations, getNonRepeaters, getObjectID, getObjectID, getObjectIDList, getPduErrorIndex, getPrincipal, getPrivPassword, getPrivProtocol, getRetries, getSecurityLevel, getSecurityModel, getSendTimeoutEvents, getSnmpOID, getSnmpOIDList, getSnmpVersion, getTargetHost, getTargetPort, getTimeout, getUserErrorCode, getUserErrorString, getVarBindCount, getWriteCommunity, isInSubTree, isSerialize, loadMibs, releaseResources, removeLogClient, removeSnmpPropertyListener, removeV3HandShakeListener, setAttemptComplete, setAttemptPartial, setAuthPassword, setAuthProtocol, setClientID, setCommunity, setContextID, setContextName, setDebug, setEngineID, setIgnoreSpecificControlCodes, setMaxNumRows, setMaxRepetitions, setMibModules, setNonRepeaters, setParams, setParams, setPrincipal, setPrivPassword, setPrivProtocol, setRetries, setSecurityLevel, setSecurityModel, setSendTimeoutEvents, setSnmpOID, setSnmpOIDList, setSnmpVersion, setTargetHost, setTargetPort, setTimeout, setVarBindCount, setWriteCommunity, snmpGet, snmpGet, snmpGetAllList, snmpGetAllVariableBindings, snmpGetAllVariables, snmpGetBulkList, snmpGetBulkVariableBindings, snmpGetBulkVariables, snmpGetList, snmpGetList, snmpGetNext, snmpGetNext, snmpGetNextList, snmpGetNextList, snmpGetNextVariable, snmpGetNextVariableBinding, snmpGetNextVariableBindings, snmpGetNextVariables, snmpGetVariable, snmpGetVariableBinding, snmpGetVariableBindings, snmpGetVariables, snmpSendInformAcknowledgement, snmpSendInformRequest, snmpSendInformRequest, snmpSendNotification, snmpSendNotification, snmpSendTrap, snmpSendTrap, snmpSet, snmpSet, snmpSetList, snmpSetVariable, snmpSetVariableList, snmpSetVariables
 
Methods inherited from class com.adventnet.snmp.beans.SnmpServer
async_create_v3_tables, create_v3_tables, genEvent, getCharacterEncoding, getHostAddress, getLocalAddresses, getMibPath, getOverwriteCMI, getPacketBufferSize, getSecLevelForTimeSync, getSecurityProvider, getSecurityTable, getSerializedMibFileName, getSimpleDateFormat, getSnmpEngineID, getSnmpEngineTable, getTimeoutInMilliSec, getTimeToWait, getUSMTable, getV3ConfigTable, getV3MsgMaxSize, initJdbcParams, initSecurityProvider, isBroadcastFeatureEnable, isLoadFromCompiledMibs, isLoadFromSerializedMibs, isLoadMibsFromDatabase, isOverwriteCMI, isOverwriteMibsInDatabase, isReadDesc, isSendPDUByGroup, isSerializeMibs, isSetAutoInformResponse, isSupportedSecurityModel, isV3DatabaseFlag, isValidateUser, manage_v3_tables, managing_v3_tables, reestablish, restoreDefaultTimeoutPolicy, setAutoInformResponse, setBroadcastFeatureEnable, setCharacterEncoding, setErrorFlagEnable, setLoadFromCompiledMibs, setLoadFromSerializedMibs, setLoadMibsFromDatabase, setMibOperations, setMibPath, setOverwriteCMI, setOverwriteMibsInDatabase, setPacketBufferSize, setReadDesc, setReceiveBufferSize, setSecLevelForTimeSync, setSendPDUByGroup, setSerializedMibFileName, setSerializeMibs, setSimpleDateFormat, setSnmpEngineBoots, setSnmpEngineID, setTimeoutInMilliSec, setTimeoutPolicy, setTimeToWait, setV3ConfigTable, setV3DatabaseFlag, setV3MsgMaxSize, setWaitTimeToRetry, validateUser
 
Methods inherited from class java.lang.Object
clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 
Methods inherited from interface com.adventnet.snmp.beans.CustomizerTemplate
create_v3_tables, getSnmpEngineTable, getUSMTable, initSecurityProvider, isSupportedSecurityModel, manage_v3_tables
 








Constructor Detail



SnmpPoller
public SnmpPoller()

This constructor is used for polling data applications.





SnmpPoller
public SnmpPoller(java.applet.Applet applet)

This constructor is used for applets.





SnmpPoller
public SnmpPoller(int protocol,
                  ProtocolOptions options)

This constructor is used for applications which use protocols
 other than UDP/IP.






Method Detail



run
public void run()

the work done by the polling thread.  
     
	The following ErrorCodes can be set: SNMP_NOT_INIT, INVALID_VERSION,
   OID_NOT_SPECIFIED, REQ_TIMEDOUT, EMPTY_VAR_BIND, IP_ADDR_NOT_SPECIFIED,
   SESSION_REMOTE_HOST_UNKNOWN, SECURITYEXP_CONNECTING_REMOTE_HOST,  UNKNOWN_ERR, 
   SNMPERROR'S defined in ErrorMessages
 INVALID_CONTEXT_NAME ,INVALID_CONTEXT_ID.


Specified by:
run in interface java.lang.Runnable


See Also:
ErrorMessages, 
SnmpTarget.getErrorCode(), 
SnmpTarget.getErrorString()





finalize
protected void finalize()
                 throws java.lang.Throwable

this cleans up if no one is using


Overrides:
finalize in class SnmpServer



Throws:
java.lang.Throwable - in case of finalization errors





getPollingStatus
public boolean getPollingStatus()

returns whether the polling of some data is going on or not. If polling has stopped
 or if the polling thread has died,it will return false.











stopPolling
public void stopPolling()

Stop the polling and Stops the thread - disables the data collection from 
 the agent and event generation.  Prior to  2.1 release, stop polling only stops the polling and not the thread.  To pause the polling stopping the thread use pausePolling.











pausePolling
public void pausePolling()

stops the polling.  Does not stop the thread - disables the data 
 collection from the agent and event generation.











restartPolling
public void restartPolling()

Restart the SNMP polling.  If the thread has died for any reason, 
 reinstantiate the polling thread and start it again.











isAutoActive
public boolean isAutoActive()

returns whether the poller will be started automatically i.e. Once if the
 objectID or poll interval is set or the first result listener is added.
 By default this method will return true and hence after setting objectID using setObjectID
 or after setting the poll interval using setPollInterval(poll interval) or after adding the
 result listener using addResultListener() the Poller will start Polling automatically.
 To avoid this, setAutoActive to false can be used. In such  case restartPolling can be used to start Polling.











setAutoActive
public void setAutoActive(boolean isAutoActive)

To make the poller to start polling automatically after setting either OID or
 poll interval or after adding the first result listener. Boolean true should be passed to this method.
 If the poller should not start polling by itself,then false should be passed in which such case,
 polling should be initiated using restartpolling method.











getPollInterval
public int getPollInterval()

get the current polling interval in seconds











setPollInterval
public void setPollInterval(int i)

set the polling interval in seconds











getAbsoluteCounters
public boolean getAbsoluteCounters()

To get whether the value returned by the poller will be the absolute value or 
 the difference between successive counters.






Returns:
true if the poller will return the absolute value of the counters and 
 false if the poller will return the difference between the successive counter values.





setObjectID
public void setObjectID(java.lang.String s)

Set the object ID specified by the String value.


Overrides:
setObjectID in class SnmpTarget


Parameters:
s - the oid to be set.





setObjectID
public void setObjectID(int index,
                        java.lang.String s)

Set the object ID value at index based on specified string


Overrides:
setObjectID in class SnmpTarget


Parameters:
index - index where the oid is to be set in the oidlist
s - oid to be set.





setObjectIDList
public void setObjectIDList(java.lang.String[] s)

Set the list of object IDs  based on the specified string array.


Overrides:
setObjectIDList in class SnmpTarget


Parameters:
s - a String array of OIDs.





setAbsoluteCounters
public void setAbsoluteCounters(boolean absoluteCounters)

sets whether counter values should be absolute - applies only for single
 variable requests.  This has an impact only on the results of the
 counter data types only. If it is set to true, the poller will return
 the absolute value of the counter. If it is set to false, the result
 returned will be a difference between successive counter values. This
 will be useful for plotting the counter values.
 For multi-oid requests, it's up to the listener
 to process the counters correctly.











genEvent
protected void genEvent(SnmpPDU pdu)

generate the events to the listeners


Overrides:
genEvent in class SnmpTarget








addResultListener
public void addResultListener(ResultListener l)

add a listener for events from this poller.  The listener listens
 for events from any or all SNMP requests.


Overrides:
addResultListener in class SnmpTarget








removeResultListener
public void removeResultListener(ResultListener l)

Remove a listener for events from this poller.


Overrides:
removeResultListener in class SnmpTarget








vetoableChange
public void vetoableChange(java.beans.PropertyChangeEvent evt)

Sets the properties constrained properties.  
  
 	PropertyChangeEvent.getNewValue() expects a Hashtable of constrainted properties.
  Constrained property set are:
  SNMP Version with key VERSION
  Host Name with key HOST
  Port Number with key PORT
  Polling Interval with key POLL
 	Timeout value with key TIMEOUT
  Retries value with key RETRIES
  Auth Protocol with key AUTHPROT
  User Name with key USERNAME
  Auth Password with key AUTHPASS
  Privacy Password with key PRIVPASS


Specified by:
vetoableChange in interface java.beans.VetoableChangeListener
Overrides:
vetoableChange in class SnmpTarget