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import snmp.*;
import java.math.*;
import java.net.*;
public class SNMPSample
{
public static void main(String args[])
{
try
{
// create a communications interface to a remote SNMP-capable device;
// need to provide the remote host's InetAddress and the community
// name for the device; in addition, need to supply the version number
// for the SNMP messages to be sent (the value 0 corresponding to SNMP
// version 1)
InetAddress hostAddress = InetAddress.getByName("10.0.1.1");
String community = "public";
int version = 0; // SNMPv1
SNMPv1CommunicationInterface comInterface = new SNMPv1CommunicationInterface(version, hostAddress, community);
// now send an SNMP GET request to retrieve the value of the SNMP variable
// corresponding to OID 1.3.6.1.2.1.2.1.0; this is the OID corresponding to
// the device identifying string, and the type is thus SNMPOctetString
String itemID = "1.3.6.1.2.1.1.1.0";
System.out.println("Retrieving value corresponding to OID " + itemID);
// the getMIBEntry method of the communications interface returns an SNMPVarBindList
// object; this is essentially a Vector of SNMP (OID,value) pairs. In this case, the
// returned Vector has just one pair inside it.
SNMPVarBindList newVars = comInterface.getMIBEntry(itemID);
// extract the (OID,value) pair from the SNMPVarBindList; the pair is just a two-element
// SNMPSequence
SNMPSequence pair = (SNMPSequence)(newVars.getSNMPObjectAt(0));
// extract the object identifier from the pair; it's the first element in the sequence
SNMPObjectIdentifier snmpOID = (SNMPObjectIdentifier)pair.getSNMPObjectAt(0);
// extract the corresponding value from the pair; it's the second element in the sequence
SNMPObject snmpValue = pair.getSNMPObjectAt(1);
// print out the String representation of the retrieved value
System.out.println("Retrieved value: type " + snmpValue.getClass().getName() + ", value " + snmpValue.toString());
// the retrieved value can be obtained from the SNMPObject using the getValue method;
// the return type of the method is the generic base class Object, and must be cast to
// the appropriate actual Java type; in this case, for an SNMPOctetString, the underlying
// Java type is a byte array[]
byte[] javaByteArrayValue = (byte[])snmpValue.getValue();
// now send an SNMP GET request to retrieve the value of the SNMP variable
// corresponding to OID 1.3.6.1.2.1.1.3.0; this is the OID corresponding to
// the uptime of the device, and the return type is thus SNMPTimeTicks
itemID = "1.3.6.1.2.1.1.3.0";
System.out.println("Retrieving value corresponding to OID " + itemID);
// the getMIBEntry method of the communications interface returns an SNMPVarBindList
// object; this is essentially a Vector of SNMP (OID,value) pairs. In this case, the
// returned Vector has just one pair inside it.
newVars = comInterface.getMIBEntry(itemID);
// extract the (OID,value) pair from the SNMPVarBindList; the pair is just a two-element
// SNMPSequence
pair = (SNMPSequence)(newVars.getSNMPObjectAt(0));
// extract the object identifier from the pair; it's the first element in the sequence
snmpOID = (SNMPObjectIdentifier)pair.getSNMPObjectAt(0);
// extract the corresponding value from the pair; it's the second element in the sequence
snmpValue = pair.getSNMPObjectAt(1);
// print out the String representation of the retrieved value
System.out.println("Retrieved value: type " + snmpValue.getClass().getName() + ", value " + snmpValue.toString());
// the retrieved value can be obtained from the SNMPObject using the getValue method;
// the return type of the method is the generic base class Object, and must be cast to
// the appropriate actual Java type; in this case, for SNMPTimeTicks, which is a subclass
// of SNMPInteger, the actual type is BigInteger (which permits arbitrarily large values to
// be represented).
BigInteger javaIntegerValue = (BigInteger)snmpValue.getValue();
// now send an SNMP GET request to simultaneously retrieve the value of the SNMP variables
// corresponding to OIDs 1.3.6.1.2.1.1.1.0 to 1.3.6.1.2.1.1.5.0
String[] itemIDs = {"1.3.6.1.2.1.1.1.0", "1.3.6.1.2.1.1.2.0", "1.3.6.1.2.1.1.3.0", "1.3.6.1.2.1.1.4.0", "1.3.6.1.2.1.1.5.0"};
System.out.println("Retrieving value corresponding to OIDs: ");
for (int i = 0; i < itemIDs.length; i++)
{
System.out.println(" " + itemIDs[i]);
}
// the getMIBEntry method of the communications interface returns an SNMPVarBindList
// object; this is essentially a Vector of SNMP (OID,value) pairs. In this case, the
// returned Vector has several pairs inside it.
newVars = comInterface.getMIBEntry(itemIDs);
// extract the (OID,value) pairs from the SNMPVarBindList; each pair is just a two-element
// SNMPSequence
for (int i = 0; i < newVars.size(); i++)
{
pair = (SNMPSequence)(newVars.getSNMPObjectAt(i));
// extract the object identifier from the pair; it's the first element in the sequence
snmpOID = (SNMPObjectIdentifier)pair.getSNMPObjectAt(0);
// extract the corresponding value from the pair; it's the second element in the sequence
snmpValue = pair.getSNMPObjectAt(1);
// print out the String representation of the retrieved value
System.out.println("Retrieved value: type " + snmpValue.getClass().getName() + ", value " + snmpValue.toString());
}
// now do get-next for the OIDS above; this will return the values for the OIDs following
// each of the supplied OIDs
System.out.println("Retrieving values _following_ OIDs: ");
for (int i = 0; i < itemIDs.length; i++)
{
System.out.println(" " + itemIDs[i]);
}
newVars = comInterface.getNextMIBEntry(itemIDs);
// extract the (OID,value) pairs from the SNMPVarBindList; each pair is just a two-element
// SNMPSequence
for (int i = 0; i < newVars.size(); i++)
{
pair = (SNMPSequence)(newVars.getSNMPObjectAt(i));
// extract the object identifier from the pair; it's the first element in the sequence
snmpOID = (SNMPObjectIdentifier)pair.getSNMPObjectAt(0);
// extract the corresponding value from the pair; it's the second element in the sequence
snmpValue = pair.getSNMPObjectAt(1);
// print out the String representation of the retrieved value
System.out.println("Retrieved value: type " + snmpValue.getClass().getName() + ", value " + snmpValue.toString());
}
// next, retrieve an entire table, and print out the results
// This uses the simple getMIBTable method, in which a single base OID is supplied,
// and all of the values of OIDs which start with that base are retrieved, one element
// at a time - this in effect retrieves the elements column-wise: all the elements in
// the first column are retrieved first, then all the elements in the second column, etc.
// This is an artifact of the way the OIDs of the elements in a table are formed in SNMP.
String baseID = "1.3.6.1.2.1.2.2.1";
System.out.println("Retrieving table corresponding to base OID " + baseID);
SNMPVarBindList tableVars = comInterface.retrieveMIBTable(baseID);
System.out.println("Number of table entries: " + tableVars.size());
// extract the (OID,value) pairs from the SNMPVarBindList; each pair is just a two-element
// SNMPSequence
for (int i = 0; i < tableVars.size(); i++)
{
pair = (SNMPSequence)(tableVars.getSNMPObjectAt(i));
// extract the object identifier from the pair; it's the first element in the sequence
snmpOID = (SNMPObjectIdentifier)pair.getSNMPObjectAt(0);
// extract the corresponding value from the pair; it's the second element in the sequence
snmpValue = pair.getSNMPObjectAt(1);
// print out the String representation of the retrieved value
System.out.println("Retrieved OID: " + snmpOID + ", type " + snmpValue.getClass().getName() + ", value " + snmpValue.toString());
}
// Next, retrieve an entire table, but row-by-row rather than entry-by-entry
// This uses the multiple getMIBTable method, in which an array of base OIDs is supplied,
// and sequences of the values of OIDs which start with that base are retrieved. This returns
// the elements row-wise: all the elements corresponding to the first row, followed by the
// elements in the second row, etc. Note also that only elements from the columns supplied
// are retrieved; this differs from the previous retrieval, in which all of the table's
// elements, from all columns, are retrieved. This method is thus more selective in the
// information retrieved. It is also more efficient, in that all of the elements in a single
// row are retrieved with a single get-request - multiple OIDs are requested in each message.
String[] baseIDs = {"1.3.6.1.2.1.2.2.1.1", "1.3.6.1.2.1.2.2.1.2", "1.3.6.1.2.1.2.2.1.3", "1.3.6.1.2.1.2.2.1.4"};
System.out.println("Retrieving table columns corresponding to base OIDs ");
for (int i = 0; i < baseIDs.length; i++)
{
System.out.println(" " + baseIDs[i]);
}
tableVars = comInterface.retrieveMIBTable(baseIDs);
System.out.println("Number of table entries: " + tableVars.size());
// extract the (OID,value) pairs from the SNMPVarBindList; each pair is just a two-element
// SNMPSequence
for (int i = 0; i < tableVars.size(); i++)
{
pair = (SNMPSequence)(tableVars.getSNMPObjectAt(i));
// extract the object identifier from the pair; it's the first element in the sequence
snmpOID = (SNMPObjectIdentifier)pair.getSNMPObjectAt(0);
// extract the corresponding value from the pair; it's the second element in the sequence
snmpValue = pair.getSNMPObjectAt(1);
// print out the String representation of the retrieved value
System.out.println("Retrieved OID: " + snmpOID + ", type " + snmpValue.getClass().getName() + ", value " + snmpValue.toString());
}
// now send an SNMP SET request to set the value of the SNMP variable
// corresponding to OID 1.3.6.1.2.1.1.4.0; this is the OID corresponding to
// the device contact person, and the type is thus SNMPOctetString;
// to set a new value, a string is supplied
itemID = "1.3.6.1.2.1.1.4.0";
SNMPOctetString newValue = new SNMPOctetString("Jon S");
System.out.println("Setting value corresponding to OID " + itemID);
System.out.println("New value: " + newValue.toString());
// the setMIBEntry method of the communications interface returns the SNMPVarBindList
// corresponding to the supplied OID and value
// This call will probably cause an SNMPSetException to be thrown, since the
// community name "public" is probably not the read/write password of the device
newVars = comInterface.setMIBEntry(itemID, newValue);
// now send an SNMP SET request to set the values of the SNMP variables
// corresponding to OID 1.3.6.1.2.1.1.4.0 and 1.3.6.1.2.1.1.5.0; the latter
// is the OID corresponding to the device name, and the type is thus SNMPOctetString;
// to set a new value, a string is supplied
String[] setItemIDs = {"1.3.6.1.2.1.1.4.0", "1.3.6.1.2.1.1.5.0"};
SNMPOctetString[] newValues = {new SNMPOctetString("Jon"), new SNMPOctetString("Jon's device")};
System.out.println("Setting value corresponding to OIDs " + itemID);
for (int i = 0; i < setItemIDs.length; i++)
{
System.out.println(" " + setItemIDs[i] + ", new values " + newValues[i]);
}
// the setMIBEntry method of the communications interface returns the SNMPVarBindList
// corresponding to the supplied OID and value
// This call will probably cause an SNMPSetException to be thrown, since the
// community name "public" is probably not the read/write password of the device
newVars = comInterface.setMIBEntry(setItemIDs, newValues);
}
catch(Exception e)
{
System.out.println("Exception during SNMP operation: " + e + "\n");
}
}
}
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