[SNMP4J] Socket closed error in Windows 7

[Frank Fock]

Hi,
There is an error in your program: main may return before the thread  
you started is finished. It is not related to SNMP4J other than the  
new release might be executed with a different speed on your system.

Best regards,
Frank


Am 17.08.2010 um 18:30 schrieb varma datla <varmakdatla at yahoo.com>:

> Hello,
> We are using snmp4j-1.9.3d asynchronously to find devices in a  
> network. All is
> working well until we tested it in Windows 7 where it is throwing  
> the  "Socket
> is closed" exception after a few seconds and stops. Even the latest  
> version
> 1.11.1 didn't seemed to work. Luckily we had an older version,  
> snmp4j-1.9.1e,
> which is working just fine without any errors.
>
> Here are the details. Could you please suggest any ideas on why this  
> is
> happening on Windows 7? or if I'm not using snmp4j appropriately.
>
>
> Environment:
> OS- Windows 7 (Firewall is off)
> SNMP4J- 1.9.3d ( also tested with 1.11.1)
> JVM- 1.6.0_13 (also tested with 1.6.0_20)
> Total addresses- 65025.
> Exception:-
> org.snmp4j.MessageException: Socket is closed
> at org.snmp4j.MessageDispatcherImpl.sendPdu(Unknown Source)
> at org.snmp4j.Snmp.sendMessage(Unknown Source)
> at org.snmp4j.Snmp.send(Unknown Source)
> at org.snmp4j.Snmp.send(Unknown Source)
> at com.some.Snmp4JUtil.send(Snmp4JUtil.java:86)
> at com.some.Snmp4JUtil$3.run(Snmp4JUtil.java:155)
>
>
> Code:
> package com.some;
>
> import java.io.BufferedReader;
> import java.io.BufferedWriter;
> import java.io.FileReader;
> import java.io.FileWriter;
> import java.io.IOException;
> import java.io.Writer;
> import java.util.LinkedHashSet;
> import java.util.Set;
>
> import org.apache.log4j.Logger;
> import org.snmp4j.CommunityTarget;
> import org.snmp4j.PDU;
> import org.snmp4j.Snmp;
> import org.snmp4j.TimeoutModel;
> import org.snmp4j.TransportMapping;
> import org.snmp4j.event.ResponseEvent;
> import org.snmp4j.event.ResponseListener;
> import org.snmp4j.mp.SnmpConstants;
> import org.snmp4j.smi.OID;
> import org.snmp4j.smi.UdpAddress;
> import org.snmp4j.smi.VariableBinding;
> import org.snmp4j.transport.DefaultUdpTransportMapping;
>
> public class Snmp4JUtil
> {
>   private static final Logger LOGGER = Logger.getLogger 
> ( Snmp4JUtil.class );
>
>   private Snmp snmp;
>   private final int [] oid = {1, 3, 6, 1, 4, 1 };
>   private final ResponseListener listener;
>
>
>   public Snmp4JUtil( final ResponseListener listener )
>   {
>      this.listener = listener;
>
>      try
>      {
>         final TransportMapping transport = new  
> DefaultUdpTransportMapping();
>         this.snmp = new Snmp( transport );
>         snmp.setTimeoutModel( getTimeoutModel( new int[]{ 500,  
> 1000 } ) );
>         snmp.listen();
>      }
>      catch (IOException e)
>      {
>         LOGGER.error( "Snmp4JUtil(). Error: " + e.getMessage() );
>      }
>   }
>
>   public void close()
>   {
>      try
>      {
>         snmp.close();
>      }
>      catch (IOException e)
>      {
>         LOGGER.error( "close(). Error: " + e.getMessage() );
>      }
>   }
>
>   public void send( final CommunityTarget target )
>   {
>
>      final PDU pdu = new PDU();
>      pdu.setType( PDU.GETNEXT );
>      pdu.add( new VariableBinding( new OID( oid ) ) );
>
>      try
>      {
>         this.snmp.send( pdu, target, null, listener);
>      }
>      catch (IOException e)
>      {
>         LOGGER.error( "send( CommunityTarget ) - address:" +
> target.getAddress() + "; error:" + e.getMessage() );
>         e.printStackTrace();
>      }
>   }
>
>   private TimeoutModel getTimeoutModel( final int[] timeoutsRetries )
>   {
>      return new TimeoutModel()
>      {
>         public long getRequestTimeout( final int totalNumberOfRetries,
>                                        final long targetTimeout )
>         {
>            long requestTimeout = 0;
>
>            for ( int i : timeoutsRetries )
>            {
>               requestTimeout += i;
>            }
>
>            return requestTimeout;
>         }
>
>         public long getRetryTimeout( final int retryCount,
>                                      final int totalNumberOfRetries,
>                                      final long targetTimeout )
>         {
>            return timeoutsRetries[retryCount];
>         }
>      };
>   }
>
>   public static void main( final String args[] )
>      throws Exception
>   {
>      final StringBuilder responses = new StringBuilder();
>
>      final ResponseListener listener = new ResponseListener()
>      {
>         @Override
>         public void onResponse( ResponseEvent event )
>         {
>            //cancel event
>            ((Snmp)event.getSource()).cancel(event.getRequest(), this);
>
>            // output response here.
>            responses.append( "Response: " + event.getResponse() )
>               .append( System.getProperty( "line.separator" ) );
>         }
>      };
>
>      final Snmp4JUtil snmpUtil = new Snmp4JUtil( listener );
>
>      // A few thousand addresses...just for testing
>      final Set<String> addresses = getAddresses( args[0] );
>
>      final Thread t = new Thread(){
>        public void run()
>        {
>           for ( final String ipAddress : addresses )
>           {
>              final CommunityTarget target = new CommunityTarget();
>
>              target.setAddress( new UdpAddress( ipAddress + "/ 
> 161" ) );
>              target.setVersion( SnmpConstants.version1 );
>              target.setRetries( 1 );
>
>              snmpUtil.send( target );
>           }
>
>           System.out.println("Done requesting..");
>
>           // Wait for few more seconds for responses..just for  
> testing.
>           try
>           {
>              Thread.sleep( 10000 );
>
>              System.out.println( "Writing response to the file.." );
>              writeResponse( responses );
>
>              snmpUtil.close();
>              System.out.println( "Done." );
>           }
>           catch ( Exception e )
>           {
>              System.err.println( "Error while sleeping/writing: " +
> e.getMessage() );
>           }
>        }
>      };
>
>      t.start();
>   }
>
>   private static void writeResponse( final StringBuilder sb )
>      throws Exception
>   {
>      final Writer output = new BufferedWriter(new FileWriter(
> "C:/responses.txt" ));
>
>      try
>      {
>        output.write( sb.toString() );
>      }
>      catch ( Exception e )
>      {
>        System.err.println( "Error while writing responses: " +  
> e.getMessage()
> );
>      }
>      finally {
>        output.close();
>      }
>   }
>
>   private static Set<String> getAddresses( final String fileName )
>      throws Exception
>   {
>      final Set<String> addresses = new LinkedHashSet<String>();
>      BufferedReader input = null;
>      try
>      {
>         input = new BufferedReader(new FileReader( fileName ) );
>
>         String strLine;
>         while ((strLine = input.readLine()) != null)
>         {
>            if ( strLine.trim().length() > 0 )
>            {
>               addresses.add( strLine );
>            }
>         }
>
>      }catch ( Exception e )
>      {
>        System.err.println( "Error while reading addresses: " +  
> e.getMessage()
> );
>      }
>      finally
>      {
>         if ( input != null )
>         {
>            input.close();
>         }
>      }
>
>      return addresses;
>   }
> }
>
>
> Thank you and I appreciate your help.
>
> Varma
>
>
>
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