SNMP4J SNMP用法小記（一）

snmp4j的jar包可以在它的官方網站http://www.snmp4j.org/上下載，我就不囉嗦了。

接下來直接貼代碼：

import java.io.IOException;

import java.util.Vector;

 

import org.snmp4j.CommunityTarget;

import org.snmp4j.PDU;

import org.snmp4j.Snmp;

import org.snmp4j.TransportMapping;

import org.snmp4j.event.ResponseEvent;

import org.snmp4j.mp.SnmpConstants;

import org.snmp4j.smi.Address;

import org.snmp4j.smi.GenericAddress;

import org.snmp4j.smi.OID;

import org.snmp4j.smi.OctetString;

import org.snmp4j.smi.VariableBinding;

import org.snmp4j.transport.DefaultUdpTransportMapping;

 

public class SnmpUtil {

 

       private Snmp snmp = null;

 

       private Address targetAddress = null;

 

       public void initComm() throws IOException {

             

              // 設置Agent方的IP和端口

              targetAddress = GenericAddress.parse("udp:127.0.0.1/161");

              TransportMapping transport = new DefaultUdpTransportMapping();

              snmp = new Snmp(transport);

              transport.listen();

       }

 

       public void sendPDU() throws IOException {

              // 設置 target

              CommunityTarget target = new CommunityTarget();

              target.setCommunity(new OctetString("public"));

              target.setAddress(targetAddress);

              // 通信不成功時的重試次數

              target.setRetries(2);

              // 超時時間

              target.setTimeout(1500);

              target.setVersion(SnmpConstants.version1);

              // 創建 PDU

              PDU pdu = new PDU();

              pdu.add(new VariableBinding(new OID(new int[] { 1, 3, 6, 1, 2, 1, 1, 5, 0 })));

              // MIB的訪問方式

              pdu.setType(PDU.GET);

              // 向Agent發送PDU，並接收Response

              ResponseEvent respEvnt = snmp.send(pdu, target);

              // 解析Response

              if (respEvnt != null && respEvnt.getResponse() != null) {

                     Vector<VariableBinding> recVBs = respEvnt.getResponse()

                                   .getVariableBindings();

                     for (int i = 0; i < recVBs.size(); i++) {

                            VariableBinding recVB = recVBs.elementAt(i);

                            System.out.println(recVB.getOid() + " : " + recVB.getVariable());

                     }

              }

       }

 

       public static void main(String[] args) {

              try {

                     SnmpUtil util = new SnmpUtil();

                     util.initComm();

                     util.sendPDU();

              } catch (IOException e) {

                     e.printStackTrace();

              }

       }

}

上面的這段代碼直接參考snmp4j API說明文檔中提供的例子，是一個最簡單的snmp4j的應用。只要你的機器裏安裝了snmp通訊組件，上面的代碼應該可以運行成功。

在上一個例子中，我們只做了讀取的工作，接下來，我們進行一下設置操作，通過Snmp修改讀取的機器名。
    public的默認權限是隻讀，要想進行寫操作，我們必須進行手動的設置。具體的做法是：進入管理工具→服務，找到Snmp Service→屬性→安全。在這個選項卡中我們可以看到public的權限是隻讀，你可以修改public的權限，也可以重新創建一個community。從安全角度來講當然應該新建一個，在這裏爲了測試方便，我就直接給public添加寫入權限了。
    接下來就可以編寫代碼了，我把上面的例子重構一下，代碼如下：

import java.io.IOException;

import java.util.Vector;

 

import org.snmp4j.CommunityTarget;

import org.snmp4j.PDU;

import org.snmp4j.Snmp;

import org.snmp4j.TransportMapping;

import org.snmp4j.event.ResponseEvent;

import org.snmp4j.mp.SnmpConstants;

import org.snmp4j.smi.Address;

import org.snmp4j.smi.GenericAddress;

import org.snmp4j.smi.OID;

import org.snmp4j.smi.OctetString;

import org.snmp4j.smi.VariableBinding;

import org.snmp4j.transport.DefaultUdpTransportMapping;

 

public class SnmpUtil {

 

       private Snmp snmp = null;

 

       private Address targetAddress = null;

 

       public void initComm() throws IOException {

             

              // 設置Agent方的IP和端口

              targetAddress = GenericAddress.parse("udp:127.0.0.1/161");

              TransportMapping transport = new DefaultUdpTransportMapping();

              snmp = new Snmp(transport);

              transport.listen();

       }

 

       public ResponseEvent sendPDU(PDU pdu) throws IOException {

              // 設置 target

              CommunityTarget target = new CommunityTarget();

              target.setCommunity(new OctetString("public"));

              target.setAddress(targetAddress);

              // 通信不成功時的重試次數

              target.setRetries(2);

              // 超時時間

              target.setTimeout(1500);

              target.setVersion(SnmpConstants.version1);

              // 向Agent發送PDU，並返回Response

              return snmp.send(pdu, target);

       }

      

       public void setPDU() throws IOException {

              // set PDU

              PDU pdu = new PDU();

              pdu.add(new VariableBinding(new OID(new int[] { 1, 3, 6, 1, 2, 1, 1, 5, 0 }), newOctetString("SNMPTEST")));

              pdu.setType(PDU.SET);

              sendPDU(pdu);

       }

      

       public void getPDU() throws IOException {

              // get PDU

              PDU pdu = new PDU();

              pdu.add(new VariableBinding(new OID(new int[] { 1, 3, 6, 1, 2, 1, 1, 5, 0 })));

              pdu.setType(PDU.GET);

              readResponse(sendPDU(pdu));

       }

      

       public void readResponse(ResponseEvent respEvnt) {

              // 解析Response

              if (respEvnt != null && respEvnt.getResponse() != null) {

                     Vector<VariableBinding> recVBs = respEvnt.getResponse()

                                   .getVariableBindings();

                     for (int i = 0; i < recVBs.size(); i++) {

                            VariableBinding recVB = recVBs.elementAt(i);

                            System.out.println(recVB.getOid() + " : " + recVB.getVariable());

                     }

              }

       }

      

       public static void main(String[] args) {

              try {

                     SnmpUtil util = new SnmpUtil();

                     util.initComm();

                     util.setPDU();

                     util.getPDU();

              } catch (IOException e) {

                     e.printStackTrace();

              }

       }

}

如果控制檯打出“1.3.6.1.2.1.1.5.0 : SNMPTEST”的消息，就說明我們的操作成功啦！