使用Java进行SNMP编程-SNMP4J-SNMPv1/v2-代码实例

使用SNMP4J可以很方便的实现一个SNMP NMS的功能。
对于SNMPv1/SNMPv2，简单的说，只需要以下几个步骤
1) 创建Snmp对象snmp

2) 创建CommunityTarget对象target，并指定community, version, address, timeout, retry等参数。

3) 创建PDU对象pdu，并指定操作类型(GET/GETNEXT/GETBULK/SET)， 添加VariableBinding(也就是待操作的OID),
    如果是GETBULK操作，还可以指定MaxRepetitions和NonRepeaters。
 注意一定要指定MaxRepetitions，默认值是0，那样不会返回任何结果。

4) 调用snmp.send(pdu, target)方法，发送请求请返回结果。

此外，SNMP4J提供了TableUtils类，可以很轻松的实现一个SNMP Walk的功能，比如一次返回一个表格下面的所有MIB值。
TableUtils类还支持指定ower bound index 和 upper bound index， 得到更小范围的结果以提高性能。这一点对于从一个很多行的表中取一部分行的数据来说很重要。

Snmp还支持异步的send方法。

下面的代码实例实现了GET, GETNEXT, GETBULK, Walk, SET操作，
以及一个利用异步send方法实现的agent discovery： 对一个广播地址发送请求，等待agent返回的应答。
如果需要对一个范围内的IP进行扫描，可以稍加改进，反复调用异步send多次发送给不同IP。

import java.io.IOException;import java.util.List;import java.util.Vector;import org.snmp4j.CommunityTarget;import org.snmp4j.PDU;import org.snmp4j.Snmp;import org.snmp4j.event.ResponseEvent;import org.snmp4j.event.ResponseListener;import org.snmp4j.mp.SnmpConstants;import org.snmp4j.smi.OID;import org.snmp4j.smi.OctetString;import org.snmp4j.smi.UdpAddress;import org.snmp4j.smi.VariableBinding;import org.snmp4j.transport.DefaultUdpTransportMapping;import org.snmp4j.util.DefaultPDUFactory;import org.snmp4j.util.TableEvent;import org.snmp4j.util.TableUtils;public class SNMPv2Test {public static void main(String[] args) throws IOException, InterruptedException {Snmp snmp = new Snmp(new DefaultUdpTransportMapping());snmp.listen();CommunityTarget target = new CommunityTarget();target.setCommunity(new OctetString("public"));target.setVersion(SnmpConstants.version2c);target.setAddress(new UdpAddress("192.168.0.100/161"));target.setTimeout(3000);//3starget.setRetries(1);sendRequest(snmp, createGetPdu(), target);sendRequest(snmp, createGetNextPdu(), target);sendRequest(snmp, createGetBulkPdu(), target);snmpWalk(snmp, target);target.setCommunity(new OctetString("private"));sendRequest(snmp, createSetPdu(), target);CommunityTarget broadcastTarget = new CommunityTarget();broadcastTarget.setCommunity(new OctetString("public"));broadcastTarget.setVersion(SnmpConstants.version2c);broadcastTarget.setAddress(new UdpAddress("192.168.0.255/161"));broadcastTarget.setTimeout(5000);//5ssendAsyncRequest(snmp, createGetNextPdu(), broadcastTarget);Thread.sleep(6000);//main thread wait 6s for the completion of asynchronous request }private static PDU createGetPdu() {PDU pdu = new PDU();pdu.setType(PDU.GET);pdu.add(new VariableBinding(new OID("1.3.6.1.2.1.1.3.0")));//sysUpTimepdu.add(new VariableBinding(new OID("1.3.6.1.2.1.1.5.0")));//sysNamepdu.add(new VariableBinding(new OID("1.3.6.1.2.1.1.5")));//expect an no_such_instance errorreturn pdu;}private static PDU createGetNextPdu() {PDU pdu = new PDU();pdu.setType(PDU.GETNEXT);pdu.add(new VariableBinding(new OID("1.3.6.1.2.1.1.3")));//sysUpTimepdu.add(new VariableBinding(new OID("1.3.6.1.2.1.1.5")));//sysNamereturn pdu;}private static PDU createGetBulkPdu() {PDU pdu = new PDU();pdu.setType(PDU.GETBULK);pdu.setMaxRepetitions(10);//must set it, default is 0pdu.setNonRepeaters(0);pdu.add(new VariableBinding(new OID("1.3.6.1.2.1.1")));//systemreturn pdu;}private static PDU createSetPdu() {PDU pdu = new PDU();pdu.setType(PDU.SET);pdu.add(new VariableBinding(new OID("1.3.6.1.2.1.1.5.0"), new OctetString("sysname")));//sysNamereturn pdu;}private static void sendRequest(Snmp snmp, PDU pdu, CommunityTarget target)throws IOException {ResponseEvent responseEvent = snmp.send(pdu, target);PDU response = responseEvent.getResponse();if (response == null) {System.out.println("TimeOut...");} else {if (response.getErrorStatus() == PDU.noError) {Vector<? extends VariableBinding> vbs = response.getVariableBindings();for (VariableBinding vb : vbs) {System.out.println(vb + " ," + vb.getVariable().getSyntaxString());}} else {System.out.println("Error:" + response.getErrorStatusText());}}}private static void sendAsyncRequest(Snmp snmp, PDU pdu, CommunityTarget target)throws IOException {snmp.send(pdu, target, null, new ResponseListener(){@Overridepublic void onResponse(ResponseEvent event) {PDU response = event.getResponse();System.out.println("Got response from " + event.getPeerAddress());if (response == null) {System.out.println("TimeOut...");} else {if (response.getErrorStatus() == PDU.noError) {Vector<? extends VariableBinding> vbs = response.getVariableBindings();for (VariableBinding vb : vbs) {System.out.println(vb + " ," + vb.getVariable().getSyntaxString());}} else {System.out.println("Error:" + response.getErrorStatusText());}}}});}private static void snmpWalk(Snmp snmp, CommunityTarget target) {TableUtils utils = new TableUtils(snmp, new DefaultPDUFactory(PDU.GETBULK));//GETNEXT or GETBULKutils.setMaxNumRowsPerPDU(5);//only for GETBULK, set max-repetitions, default is 10OID[] columnOids = new OID[] {new OID("1.3.6.1.2.1.1.9.1.2"),//sysORIDnew OID("1.3.6.1.2.1.1.9.1.3"),//sysORDescrnew OID("1.3.6.1.2.1.1.9.1.5")//wrong OID, expect an null in in VariableBinding array};// If not null, all returned rows have an index in a range (lowerBoundIndex, upperBoundIndex]List<TableEvent> l = utils.getTable(target, columnOids, new OID("3"), new OID("10"));for (TableEvent e : l) {System.out.println(e);}}}