SNMP Call from Java

SNMP code for clearning a port using SNMPJ , I have implemented this in Turbine/Velocity framework as an ajax call .

package org.mymodule;



import org.apache.turbine.util.RunData;

import org.apache.velocity.context.Context;

import org.mymodule.modules.util.LMLab;

import org.netsnmp.* ;

import org.netsnmp.ASN.INTEGER;

import org.netsnmp.ASN.OCTET_STR ;



public class Snmp extends SecureScreen {



public void doBuildTemplate(RunData data, Context context) throws Exception

{

data.setContentType("text/xml");

LMLab lab = (LMLab)data.getSession().getAttribute("sellab");

String community = lab.getCommunitystr();

if ((community == null)||(community.equals("")))

throw new Exception("ERROR-NO COMMUNITY STRING");



NetSNMPSession session ;

MyListener listener ;

PDU pdu ;

OID sysLocationOID ;

INTEGER lineno;

int lnlength;



String host = data.getParameters().getString("ip",null);

//String community = "private";

String newLocation = data.getParameters().getString("port",null);



if (host == null)

throw new Exception("ERROR-NO HOST");



if (newLocation == null)

throw new Exception("ERROR-NO PORT");

lnlength =newLocation.length() ;

if (lnlength >2)

lineno = new INTEGER(Integer.valueOf(newLocation.substring(lnlength-2,lnlength)).intValue());

else

lineno = new INTEGER(Integer.valueOf(newLocation).intValue());

/*;

*  Open a session to the remote host

*/

session = new NetSNMPSession(host, community) ;



/*

* Create a PDU that will perform a 'SET' operation

*/

pdu = new PDU(NetSNMP.MSG_SET) ;



/*

* Create an OID for the systemLocation

*/

try {

//sysLocationOID = new DefaultOID("SNMPv2-MIB::sysLocation.0") ;

//sysLocationOID = new DefaultOID("SNMPv2-MIB::tsClrTtyLine.0") ;



sysLocationOID = new DefaultOID(".1.3.6.1.4.1.9.2.9.10.0") ;



/*

* Add an OCTET_STR value to the PDU that will contain the new

* system location.

*/

//pdu.addEntry(sysLocationOID, new OCTET_STR(" integer "+newLocation)) ;

//        pdu.append()

PDU.entry pe = new PDU.entry(sysLocationOID,lineno);

PDU.entry[] peArray = {pe};

pdu.setEntries(peArray);



/*

* create a new listener instance and add it to the listeners for the session

*/

listener = new MyListener() ;

session.addListener(listener) ;



synchronized ( listener ) {

session.send(pdu, null) ;

listener.wait() ;



if( listener.success )

context.put("msg","SUCCESS");

else {

//System.out.println("operation failed") ;

context.put("msg","ERROR-TIMEDOUT");

}

}





}

catch( MIBItemNotFound e ) {

/*System.out.println("The sysLocation Object was not found.") ;

System.out.println("Please ensure that the MIBDIRS and MIBS") ;

System.out.println("environmental variables are set properly");*/

context.put("msg","ERROR-SYSLOCATION");

return ; // NOT REACHED

}

catch (NetSNMPSendError e) {

//System.out.println("An error occurred sending the pdu") ;

context.put("msg","ERROR-NETSNMP");

}

catch (InterruptedException e) {

//System.out.println("the wait operation was interrupted") ;

context.put("msg","ERROR-INTERRUPTED");

}

catch(Exception e)

{

context.put("msg",e.getMessage());

}







/*

* The actionPerformed method will be called on a different thread.   Synchronize

* this thread with the thread that it will be called upon with a 'synchronized' block.

*/



/*synchronized ( listener ) {

try {*/

/*

*  Send the pdu to the remote agent

*/

//session.send(pdu, null) ;





/*

* wait for the listener actionPerformed method to notify that

* operation has been completed

*/

/*listener.wait() ;



if( !listener.success ) {

System.out.println("operation failed") ;



}

} // try

catch (NetSNMPSendError e) {

System.out.println("An error occurred sending the pdu") ;

}

catch (InterruptedException e) {

System.out.println("the wait operation was interrupted") ;

}



} // synchronized

*/

}



/**

* Class that will receive and process the response from the remote agent.

*/

public static class MyListener implements NetSNMPAction {



boolean success = true ;



/**

* @see org.netsnmp.NetSNMPAction#actionPerformed(int, NetSNMPSession, PDU, Object)

*/

public synchronized boolean actionPerformed(int result, NetSNMPSession session, PDU pdu, Object o) throws Throwable {

if( result == NetSNMP.STAT_TIMEOUT ) {

//System.out.println("Operation timed out.  Ensure that your remote agent is running and that the community parameter is correct") ;

success = false ;

this.notify() ; // notify that the operation has completed

return true ; // keep calling other registerred listeners, if any

} // if



if( pdu.errStatus != 0 ) {

//System.out.println("Set operation failed.  Ensure that the security info you specified provides write access to the sysLocation Object") ;

success = false ;

this.notify() ; // notify that the operation has completed

return true ;

}   



this.notify() ; // notify that the operation has completed

return true ;

}



}



}

Dynamic SQL from Java use any number of parameters

Following is the Code that uses Java and Oracle . Its an utility to do a dynamic search without defining the sql . SQL is generated on the fly ( dynamically ) at runtime . You may have to tweak the sql generated for your purpose , but you can resue most of the Code

Params can be changed to include a variety of search options
1.Quotes for Exact Search
2. % for wider search
- abc% means starts with "abc"
- %xyz means ends with "xyz"
3.Use () to specify OR condition e.g.,(abc , efg)
4.Search is Non-Case Sensitive

One limitation is that all the parameters are created by AND condition .However you can extend the utility class to include
that feature too .

Sql Utlity class

import java.util.StringTokenizer;

public class Sql {
private String sOn ; // column name to search
private String sParam; // exact search parameter

public Sql(String sOn , String sParam)
{
this.sOn = sOn;
this.sParam = sParam;
}
// Generate the sql
public String getSQL()
{
StringBuffer sSql = new StringBuffer();
String sToken = new String();
String sTemp = new String();

if(sParam.startsWith("\"")&& sParam.endsWith("\""))
{
sSql.append("AND UPPER(").append(sOn).append(") =").append("'").append((sParam.substring(sParam.indexOf("\"")+1,sParam.lastIndexOf("\""))).toUpperCase()).append("'");
}else if(sParam.startsWith("(")&& sParam.endsWith(")"))
{
sTemp = sParam.substring(sParam.indexOf("(")+1,sParam.indexOf(")")) ;
sSql.append("AND UPPER(").append(sOn).append(") IN (");
StringTokenizer st1 = new StringTokenizer(sTemp,",");
while ( st1.hasMoreTokens() ) {
sToken = st1.nextToken();
if(sToken !=null)
{
sToken = sToken.trim().toUpperCase();
sSql.append("'").append(sToken).append("',");
}
}
sSql = new StringBuffer(sSql.substring(0,sSql.length()-1)) ;
sSql.append(")");
}
else if(sParam.startsWith("%") || sParam.endsWith("%"))
{
sSql.append("AND UPPER(").append(sOn).append(") LIKE '").append(sParam.toUpperCase()).append("'");

}else if(sParam!=null&& !sParam.equals(""))
{
sSql.append("AND UPPER(").append(sOn).append(") LIKE '%").append(sParam.toUpperCase()).append("%'");

}
return sSql.toString();
}
}

Utlity method


public String getSearchSQL(Vector v)
{
StringBuffer sql = new StringBuffer();
for(Enumeration e=v.elements();e.hasMoreElements();)
{
sql.append(((Sql)e.nextElement()).getSQL() );

}
return sql.toString();
}


Application Logic


Vector v = new Vector();
v.add(new Sql("<name of table column name>", <value to search on use empty string if null> ));

.....repeat for all the parameters to be searched on

<sql string> = getSearchSQL(v);

Bingo !

Velocity templates to send email

Here is a code sample for creating email from Velocity

Template template = null;
StringWriter sw = new StringWriter();
try {
template = Velocity.getTemplate(