2014/12/15

如何使用 snmp4j 進行查詢

SNMP 的原理跟概念 分為 Agent 與 Client 兩端需要處理,如果不是提供機器與服務的,就不需要做 Agent 這個 Server,一般最基本的 SNMP 程式設計是撰寫 SNMP Client,Client 又有兩個部份 (1) SNMP GET, Walk (2) Trap Receiver,以下以 snmp4j 套件提供第一個部份 SNMP GET, Walk 的範例。

SNMP GET

給予 server ip,這邊刻意將程式區分為 connect, snmpget, close 三個部份,因為 UDP 本身是 connection less 的一種網路連線,未來在使用時,只要連結起來,應該就能持續發送 SNMP GET,並取得結果。

snmpGet 有兩種 method,第一種就單純地只接受一個 oid 參數,第二種,是接受一個 oid List,可一次查詢多個 oid 的結果。

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.Vector;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.snmp4j.CommunityTarget;
import org.snmp4j.PDU;
import org.snmp4j.Snmp;
import org.snmp4j.event.ResponseEvent;
import org.snmp4j.mp.SnmpConstants;
import org.snmp4j.smi.GenericAddress;
import org.snmp4j.smi.Integer32;
import org.snmp4j.smi.Null;
import org.snmp4j.smi.OID;
import org.snmp4j.smi.OctetString;
import org.snmp4j.smi.Variable;
import org.snmp4j.smi.VariableBinding;
import org.snmp4j.transport.DefaultUdpTransportMapping;

public class SnmpGet {
    public static Logger logger = LoggerFactory.getLogger(SnmpGet.class
            .getName());

    private static int version = SnmpConstants.version1;
    private static String protocol = "udp";

    private static CommunityTarget target = null;
    private static DefaultUdpTransportMapping udpTransportMapping = null;
    private static Snmp snmp = null;

    public static void main(String[] args) {

        String ip = "192.168.1.8";
        String community = "public";
        int port = 161;

        Variable var = null;
        SnmpGet tester = new SnmpGet();
        // tester.snmpGet(ip, port, community, oidval);
        try {
            tester.connect(ip, port, community);
            // System Uptime(系統運行時間) 的 oid, 最前面的 . 可以忽略不寫
            String oid = ".1.3.6.1.2.1.1.3.0";
            var = tester.snmpGet(oid);
            logger.info(oid + " = " + var);

            Thread.sleep(3 * 1000);
            logger.info("");
            oid = ".1.3.6.1.2.1.1.1.0";
            var = tester.snmpGet(oid);
            logger.info(oid + " = " + var);

            Thread.sleep(3 * 1000);
            logger.info("");
            logger.info("SNMP GetList");
            List<String> oidList = new ArrayList<String>();
            oidList.add(".1.3.6.1.2.1.1.1.0");
            oidList.add(".1.3.6.1.2.1.1.3.0");
            oidList.add(".1.3.6.1.2.1.1.5.0");

            List<VariableBinding> vblist = tester.snmpGet(oidList);
            for (VariableBinding vb : vblist) {
                logger.info("oid:" + vb.getOid() + ", var=" + vb.getVariable());
            }
        } catch (Exception e) {
            logger.error("Error:", e);
        } finally {
            tester.close();
        }
    }

    public void connect(String ip, int port, String community) throws Exception {
        String address = protocol + ":" + ip + "/" + port;
        // CommunityTarget target = SnmpUtil.createCommunityTarget(address,
        // community, version, 2 * 1000L, 3);

        target = new CommunityTarget();
        target.setCommunity(new OctetString(community));
        target.setAddress(GenericAddress.parse(address));
        target.setVersion(version);
        target.setTimeout(2 * 1000L); // milliseconds
        target.setRetries(3); // retry 3次

        try {
            udpTransportMapping = new DefaultUdpTransportMapping();
            // 這裡一定要呼叫 listen, 才能收到結果
            udpTransportMapping.listen();
            snmp = new Snmp(udpTransportMapping);

        } catch (Exception e) {
            logger.error("Error", e);
            throw e;
        }
    }

    public void close() {
        if (snmp != null) {
            try {
                snmp.close();
            } catch (IOException ex1) {
                snmp = null;
            }
        }
        if (udpTransportMapping != null) {
            try {
                udpTransportMapping.close();
            } catch (IOException ex2) {
                udpTransportMapping = null;
            }
        }
    }

    public Variable snmpGet(String oid) throws Exception {
        try {
            PDU pdu = new PDU();
            // pdu.add(new VariableBinding(new OID(new
            // int[]{1,3,6,1,2,1,1,2})));
            pdu.add(new VariableBinding(new OID(oid)));
            pdu.setType(PDU.GET);

            // 以同步的方式發送 snmp get, 會等待target 設定的 timeout 時間結束後
            // 就會以 Request time out 的方式 return 回來
            ResponseEvent response = snmp.send(pdu, target);
            // logger.debug("PeerAddress:" + response.getPeerAddress());
            PDU responsePdu = response.getResponse();

            if (responsePdu == null) {
                logger.debug("Request time out");
            } else {
                Vector<?> vbVect = responsePdu.getVariableBindings();
                logger.debug("vb size:" + vbVect.size());
                if (vbVect.size() == 0) {
                    logger.debug(" pdu vb size is 0 ");
                } else {
                    Object obj = vbVect.firstElement();
                    VariableBinding vb = (VariableBinding) obj;
                    // logger.debug(vb.getOid() + " = " + vb.getVariable());

                    // logger.info("success finish snmp get the oid!");
                    return vb.getVariable();
                }
            }

        } catch (Exception e) {
            logger.error("Error", e);
            throw e;
        }
        return null;
    }

    public List<VariableBinding> snmpGet(List<String> oidList) throws Exception {
        try {
            PDU pdu = new PDU();
            pdu.setType(PDU.GET);
            for (String oid : oidList) {
                pdu.add(new VariableBinding(new OID(oid)));
            }

            // 以同步的方式發送 snmp get, 會等待target 設定的 timeout 時間結束後
            // 就會以 Request time out 的方式 return 回來
            ResponseEvent response = snmp.send(pdu, target);
            // logger.debug("PeerAddress:" + response.getPeerAddress());
            PDU responsePdu = response.getResponse();

            if (responsePdu == null) {
                logger.debug("Request time out");
            } else {
                logger.debug(" response pdu vb size is " + responsePdu.size());
                List<VariableBinding> datalist = new ArrayList<VariableBinding>();
                for (int i = 0; i < responsePdu.size(); i++) {
                    VariableBinding vb = responsePdu.get(i);
                    // logger.debug(vb.getOid() + "=" + vb.getVariable());
                    datalist.add(vb);
                }
                return datalist;
            }

        } catch (Exception e) {
            logger.error("Error", e);
            throw e;
        }
        return null;
    }
}

執行結果

2014-12-04 17:19:11,055 [main] DEBUG SnmpGet 145
 vb size:1
2014-12-04 17:19:11,083 [main] INFO  SnmpGet 50
 .1.3.6.1.2.1.1.3.0 = 1 day, 1:13:23.16
2014-12-04 17:19:14,084 [main] INFO  SnmpGet 53

2014-12-04 17:19:14,085 [main] DEBUG SnmpGet 145
 vb size:1
2014-12-04 17:19:14,086 [main] INFO  SnmpGet 56
 .1.3.6.1.2.1.1.1.0 = Linux server.maxkit.com.tw 2.6.32-431.el6.i686 #1 SMP Fri Nov 22 00:26:36 UTC 2013 i686

SNMP walk

這是使用 GETNext 的方式,當有下一個OID 時,就自動往下抓取,直到沒有資料為止。

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.Vector;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.snmp4j.CommunityTarget;
import org.snmp4j.PDU;
import org.snmp4j.Snmp;
import org.snmp4j.event.ResponseEvent;
import org.snmp4j.mp.SnmpConstants;
import org.snmp4j.smi.GenericAddress;
import org.snmp4j.smi.Integer32;
import org.snmp4j.smi.Null;
import org.snmp4j.smi.OID;
import org.snmp4j.smi.OctetString;
import org.snmp4j.smi.Variable;
import org.snmp4j.smi.VariableBinding;
import org.snmp4j.transport.DefaultUdpTransportMapping;

public class SnmpGet {
    public static Logger logger = LoggerFactory.getLogger(SnmpGet.class
            .getName());

    private static int version = SnmpConstants.version1;
    private static String protocol = "udp";

    private static CommunityTarget target = null;
    private static DefaultUdpTransportMapping udpTransportMapping = null;
    private static Snmp snmp = null;

    public static void main(String[] args) {

        String ip = "192.168.1.8";
        String community = "public";
        int port = 161;

        Variable var = null;
        SnmpGet tester = new SnmpGet();
        // tester.snmpGet(ip, port, community, oidval);
        try {
            tester.connect(ip, port, community);
            logger.info("");
            logger.info("SNMP walk");

            vblist = tester.snmpWalk("1.3.6.1.2.1.1");
            for (VariableBinding vb : vblist) {
                logger.info("oid:" + vb.getOid() + ", var=" + vb.getVariable());
            }
        } catch (Exception e) {
            logger.error("Error:", e);
        } finally {
            tester.close();
        }
    }

    public void connect(String ip, int port, String community) throws Exception {
        String address = protocol + ":" + ip + "/" + port;
        // CommunityTarget target = SnmpUtil.createCommunityTarget(address,
        // community, version, 2 * 1000L, 3);

        target = new CommunityTarget();
        target.setCommunity(new OctetString(community));
        target.setAddress(GenericAddress.parse(address));
        target.setVersion(version);
        target.setTimeout(2 * 1000L); // milliseconds
        target.setRetries(3); // retry 3次

        try {
            udpTransportMapping = new DefaultUdpTransportMapping();
            // 這裡一定要呼叫 listen, 才能收到結果
            udpTransportMapping.listen();
            snmp = new Snmp(udpTransportMapping);

        } catch (Exception e) {
            logger.error("Error", e);
            throw e;
        }
    }

    public void close() {
        if (snmp != null) {
            try {
                snmp.close();
            } catch (IOException ex1) {
                snmp = null;
            }
        }
        if (udpTransportMapping != null) {
            try {
                udpTransportMapping.close();
            } catch (IOException ex2) {
                udpTransportMapping = null;
            }
        }
    }

    /**
     * 1)responsePDU == null<br>
     * 2)responsePDU.getErrorStatus() != 0<br>
     * 3)responsePDU.get(0).getOid() == null<br>
     * 4)responsePDU.get(0).getOid().size() < targetOID.size()<br>
     * 5)targetOID.leftMostCompare(targetOID.size(),responsePDU.get(0).getOid())
     * !=0<br>
     * 6)Null.isExceptionSyntax(responsePDU.get(0).getVariable().getSyntax())<br>
     * 7)responsePDU.get(0).getOid().compareTo(targetOID) <= 0<br>
     */
    public List<VariableBinding> snmpWalk(String targetOid) {
        OID targetOID = new OID(targetOid);

        PDU requestPDU = new PDU();
        requestPDU.setType(PDU.GETNEXT);
        requestPDU.add(new VariableBinding(targetOID));

        try {
            List<VariableBinding> vblist = new ArrayList<VariableBinding>();
            boolean finished = false;
            while (!finished) {
                VariableBinding vb = null;
                ResponseEvent response = snmp.send(requestPDU, target);
                PDU responsePDU = response.getResponse();

                if (null == responsePDU) {
                    logger.debug("responsePDU == null");
                    finished = true;
                    break;
                } else {
                    vb = responsePDU.get(0);
                }
                // check finish
                finished = checkWalkFinished(targetOID, responsePDU, vb);
                if (!finished) {
                    // logger.debug("vb:" + vb.toString());
                    vblist.add(vb);
                    // Set up the variable binding for the next entry.
                    requestPDU.setRequestID(new Integer32(0));
                    requestPDU.set(0, vb);
                }
            }
            // logger.debug("success finish snmp walk!");
            return vblist;
        } catch (Exception e) {
            logger.error("Error: ", e);
        }
        return null;
    }

    /**
     * check snmp walk finish
     * 
     * @param resquestPDU
     * @param targetOID
     * @param responsePDU
     * @param vb
     * @return
     */
    private boolean checkWalkFinished(OID targetOID, PDU responsePDU,
            VariableBinding vb) {
        boolean finished = false;
        if (responsePDU.getErrorStatus() != 0) {
            logger.debug("responsePDU.getErrorStatus() != 0 ");
            logger.debug(responsePDU.getErrorStatusText());
            finished = true;
        } else if (vb.getOid() == null) {
            logger.debug("vb.getOid() == null");
            finished = true;
        } else if (vb.getOid().size() < targetOID.size()) {
            logger.debug("vb.getOid().size() < targetOID.size()");
            finished = true;
        } else if (targetOID.leftMostCompare(targetOID.size(), vb.getOid()) != 0) {
            logger.debug("targetOID.leftMostCompare() != 0");
            finished = true;
        } else if (Null.isExceptionSyntax(vb.getVariable().getSyntax())) {
            logger.debug("Null.isExceptionSyntax(vb.getVariable().getSyntax())");
            finished = true;
        } else if (vb.getOid().compareTo(targetOID) <= 0) {
            logger.debug("Variable received is not "
                    + "lexicographic successor of requested " + "one:");
            logger.debug(vb.toString() + " <= " + targetOID);
            finished = true;
        }
        return finished;

    }
}

測試結果

2014-12-04 17:19:17,087 [main] INFO  SnmpGet 60
 SNMP GetList
2014-12-04 17:19:17,091 [main] DEBUG SnmpGet 182
  response pdu vb size is 3
2014-12-04 17:19:17,091 [main] INFO  SnmpGet 68
 oid:1.3.6.1.2.1.1.1.0, var=Linux server.maxkit.com.tw 2.6.32-431.el6.i686 #1 SMP Fri Nov 22 00:26:36 UTC 2013 i686
2014-12-04 17:19:17,092 [main] INFO  SnmpGet 68
 oid:1.3.6.1.2.1.1.3.0, var=1 day, 1:13:29.25
2014-12-04 17:19:17,092 [main] INFO  SnmpGet 68
 oid:1.3.6.1.2.1.1.5.0, var=server.maxkit.com.tw
2014-12-04 17:19:20,092 [main] INFO  SnmpGet 72

2014-12-04 17:19:20,093 [main] INFO  SnmpGet 73
 SNMP walk
2014-12-04 17:19:20,130 [main] DEBUG SnmpGet 276
 targetOID.leftMostCompare() != 0
2014-12-04 17:19:20,130 [main] INFO  SnmpGet 77
 oid:1.3.6.1.2.1.1.1.0, var=Linux server.maxkit.com.tw 2.6.32-431.el6.i686 #1 SMP Fri Nov 22 00:26:36 UTC 2013 i686
2014-12-04 17:19:20,130 [main] INFO  SnmpGet 77
 oid:1.3.6.1.2.1.1.2.0, var=1.3.6.1.4.1.8072.3.2.10
2014-12-04 17:19:20,131 [main] INFO  SnmpGet 77
 oid:1.3.6.1.2.1.1.3.0, var=1 day, 1:13:32.26
2014-12-04 17:19:20,131 [main] INFO  SnmpGet 77
 oid:1.3.6.1.2.1.1.4.0, var=Root <root@localhost> (configure /etc/snmp/snmp.local.conf)
2014-12-04 17:19:20,131 [main] INFO  SnmpGet 77
 oid:1.3.6.1.2.1.1.5.0, var=server.maxkit.com.tw
2014-12-04 17:19:20,132 [main] INFO  SnmpGet 77
 oid:1.3.6.1.2.1.1.6.0, var=Unknown (edit /etc/snmp/snmpd.conf)
2014-12-04 17:19:20,132 [main] INFO  SnmpGet 77
 oid:1.3.6.1.2.1.1.8.0, var=0:00:00.01
2014-12-04 17:19:20,132 [main] INFO  SnmpGet 77
 oid:1.3.6.1.2.1.1.9.1.2.1, var=1.3.6.1.6.3.11.2.3.1.1
2014-12-04 17:19:20,132 [main] INFO  SnmpGet 77
 oid:1.3.6.1.2.1.1.9.1.2.2, var=1.3.6.1.6.3.15.2.1.1
2014-12-04 17:19:20,133 [main] INFO  SnmpGet 77
 oid:1.3.6.1.2.1.1.9.1.2.3, var=1.3.6.1.6.3.10.3.1.1
2014-12-04 17:19:20,133 [main] INFO  SnmpGet 77
 oid:1.3.6.1.2.1.1.9.1.2.4, var=1.3.6.1.6.3.1
2014-12-04 17:19:20,133 [main] INFO  SnmpGet 77
 oid:1.3.6.1.2.1.1.9.1.2.5, var=1.3.6.1.2.1.49
2014-12-04 17:19:20,133 [main] INFO  SnmpGet 77
 oid:1.3.6.1.2.1.1.9.1.2.6, var=1.3.6.1.2.1.4
2014-12-04 17:19:20,133 [main] INFO  SnmpGet 77
 oid:1.3.6.1.2.1.1.9.1.2.7, var=1.3.6.1.2.1.50
2014-12-04 17:19:20,133 [main] INFO  SnmpGet 77
 oid:1.3.6.1.2.1.1.9.1.2.8, var=1.3.6.1.6.3.16.2.2.1
2014-12-04 17:19:20,133 [main] INFO  SnmpGet 77
 oid:1.3.6.1.2.1.1.9.1.3.1, var=The MIB for Message Processing and Dispatching.
2014-12-04 17:19:20,134 [main] INFO  SnmpGet 77
 oid:1.3.6.1.2.1.1.9.1.3.2, var=The MIB for Message Processing and Dispatching.
2014-12-04 17:19:20,134 [main] INFO  SnmpGet 77
 oid:1.3.6.1.2.1.1.9.1.3.3, var=The SNMP Management Architecture MIB.
2014-12-04 17:19:20,134 [main] INFO  SnmpGet 77
 oid:1.3.6.1.2.1.1.9.1.3.4, var=The MIB module for SNMPv2 entities
2014-12-04 17:19:20,134 [main] INFO  SnmpGet 77
 oid:1.3.6.1.2.1.1.9.1.3.5, var=The MIB module for managing TCP implementations
2014-12-04 17:19:20,134 [main] INFO  SnmpGet 77
 oid:1.3.6.1.2.1.1.9.1.3.6, var=The MIB module for managing IP and ICMP implementations
2014-12-04 17:19:20,134 [main] INFO  SnmpGet 77
 oid:1.3.6.1.2.1.1.9.1.3.7, var=The MIB module for managing UDP implementations
2014-12-04 17:19:20,134 [main] INFO  SnmpGet 77
 oid:1.3.6.1.2.1.1.9.1.3.8, var=View-based Access Control Model for SNMP.
2014-12-04 17:19:20,135 [main] INFO  SnmpGet 77
 oid:1.3.6.1.2.1.1.9.1.4.1, var=0:00:00.01
2014-12-04 17:19:20,136 [main] INFO  SnmpGet 77
 oid:1.3.6.1.2.1.1.9.1.4.2, var=0:00:00.01
2014-12-04 17:19:20,137 [main] INFO  SnmpGet 77
 oid:1.3.6.1.2.1.1.9.1.4.3, var=0:00:00.01
2014-12-04 17:19:20,138 [main] INFO  SnmpGet 77
 oid:1.3.6.1.2.1.1.9.1.4.4, var=0:00:00.01
2014-12-04 17:19:20,139 [main] INFO  SnmpGet 77
 oid:1.3.6.1.2.1.1.9.1.4.5, var=0:00:00.01
2014-12-04 17:19:20,143 [main] INFO  SnmpGet 77
 oid:1.3.6.1.2.1.1.9.1.4.6, var=0:00:00.01
2014-12-04 17:19:20,143 [main] INFO  SnmpGet 77
 oid:1.3.6.1.2.1.1.9.1.4.7, var=0:00:00.01
2014-12-04 17:19:20,144 [main] INFO  SnmpGet 77
 oid:1.3.6.1.2.1.1.9.1.4.8, var=0:00:00.01

SNMP Asynchronous Get

如果在程式中,無法在發送 snmp request 之後,直接等待結果,例如在 UI 界面上發送 request,但 UI 無法被 blocking 以等待 response 或 timeout 的狀況下,我們就必須要使用非同步 SNMP Get。

程式中主要是利用 ThreadPool,以 multithread 的方式,在背景中發送 request,並以 event listener 作為 call back function。

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.snmp4j.CommunityTarget;
import org.snmp4j.MessageDispatcherImpl;
import org.snmp4j.PDU;
import org.snmp4j.Snmp;
import org.snmp4j.event.ResponseEvent;
import org.snmp4j.event.ResponseListener;
import org.snmp4j.mp.MPv1;
import org.snmp4j.mp.MPv2c;
import org.snmp4j.mp.MPv3;
import org.snmp4j.mp.SnmpConstants;
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;
import org.snmp4j.util.MultiThreadedMessageDispatcher;
import org.snmp4j.util.ThreadPool;
import org.snmp4j.util.WorkerPool;

public class SnmpClientAsync {
    public static Logger logger = LoggerFactory.getLogger(SnmpClientAsync.class
            .getName());

    private static int version = SnmpConstants.version1;
    private static String protocol = "udp";

    private static CommunityTarget target = null;
    private static DefaultUdpTransportMapping udpTransportMapping = null;
    private static Snmp snmp = null;
    private WorkerPool threadPool = null;

    public static void main(String[] args) {

        String ip = "192.168.1.8";
        String community = "public";
        int port = 161;

        SnmpClientAsync tester = new SnmpClientAsync();
        try {
            tester.connect(ip, port, community);
            logger.info("");
            logger.info("SNMP GetList");
            List<String> oidList = new ArrayList<String>();
            oidList.add(".1.3.6.1.2.1.1.1.0");
            oidList.add(".1.3.6.1.2.1.1.3.0");
            oidList.add(".1.3.6.1.2.1.1.5.0");

            tester.snmpGet(oidList);

            // 非同步,必須等待一段處理時間
            Thread.sleep(3*1000);
        } catch (Exception e) {
            logger.error("Error:", e);
        } finally {
            tester.close();
        }
    }

    public void connect(String ip, int port, String community) throws Exception {
        String address = protocol + ":" + ip + "/" + port;

        target = new CommunityTarget();
        target.setCommunity(new OctetString(community));
        target.setAddress(GenericAddress.parse(address));
        target.setVersion(version);
        target.setTimeout(2 * 1000L); // milliseconds
        target.setRetries(3); // retry 3次

        try {
            threadPool = ThreadPool.create(ip + "SNMPWorkPool", 2);
            MultiThreadedMessageDispatcher dispatcher = new MultiThreadedMessageDispatcher(
                    threadPool, new MessageDispatcherImpl());

            udpTransportMapping = new DefaultUdpTransportMapping();

            snmp = new Snmp(dispatcher, udpTransportMapping);
            snmp.getMessageDispatcher().addMessageProcessingModel(new MPv1());
            snmp.getMessageDispatcher().addMessageProcessingModel(new MPv2c());
            snmp.getMessageDispatcher().addMessageProcessingModel(new MPv3());
            snmp.listen();
        } catch (Exception e) {
            logger.error("Error", e);
            throw e;
        }
    }

    public void close() {
        if (snmp != null) {
            try {
                snmp.close();
            } catch (IOException ex1) {
                snmp = null;
            }
        }
        if (udpTransportMapping != null) {
            try {
                udpTransportMapping.close();
            } catch (IOException ex2) {
                udpTransportMapping = null;
            }
        }
        if (threadPool != null) {
            threadPool.stop();
            threadPool = null;
        }
    }

    public void snmpGet(List<String> oidList) throws Exception {
        try {
            PDU pdu = new PDU();
            pdu.setType(PDU.GET);
            for (String oid : oidList) {
                pdu.add(new VariableBinding(new OID(oid)));
            }

            snmp.send(pdu, target, null, listener);
        } catch (Exception e) {
            logger.error("Error", e);
            throw e;
        }
    }

    public void printResponse(List<VariableBinding> datalist) {
        for (VariableBinding vb : datalist) {
            logger.info("oid:" + vb.getOid() + ", var=" + vb.getVariable());
        }
    }

    ResponseListener listener = new ResponseListener() {
        public void onResponse(ResponseEvent event) {
            ((Snmp) event.getSource()).cancel(event.getRequest(), this);
            PDU response = event.getResponse();
            PDU request = event.getRequest();
            //logger.debug("[request]:" + request);

            if (response == null) {
                logger.debug("[ERROR]: response is null");
            } else if (response.getErrorStatus() != 0) {
                logger.debug("[ERROR]: response status"
                        + response.getErrorStatus() + " Text:"
                        + response.getErrorStatusText());
            } else {
                logger.debug("Received response Success!!!");
                List<VariableBinding> datalist = new ArrayList<VariableBinding>();
                for (int i = 0; i < response.size(); i++) {
                    VariableBinding vb = response.get(i);
                    logger.debug(vb.toString());
                    datalist.add(vb);
                }
                printResponse(datalist);
            }
        }
    };

}

測試結果

2014-12-08 10:18:07,548 [main] INFO  SnmpClientAsync 49

2014-12-08 10:18:07,581 [main] INFO  SnmpClientAsync 50
 SNMP GetList
2014-12-08 10:18:07,607 [192.168.1.8SNMPWorkPool.0] DEBUG SnmpClientAsync 151
 Received response Success!!!
2014-12-08 10:18:07,607 [192.168.1.8SNMPWorkPool.0] DEBUG SnmpClientAsync 155
 1.3.6.1.2.1.1.1.0 = Linux koko.maxkit.com.tw 2.6.32-431.el6.i686 #1 SMP Fri Nov 22 00:26:36 UTC 2013 i686
2014-12-08 10:18:07,610 [192.168.1.8SNMPWorkPool.0] DEBUG SnmpClientAsync 155
 1.3.6.1.2.1.1.3.0 = 4 days, 18:12:20.49
2014-12-08 10:18:07,611 [192.168.1.8SNMPWorkPool.0] DEBUG SnmpClientAsync 155
 1.3.6.1.2.1.1.5.0 = koko.maxkit.com.tw
2014-12-08 10:18:07,611 [192.168.1.8SNMPWorkPool.0] INFO  SnmpClientAsync 133
 oid:1.3.6.1.2.1.1.1.0, var=Linux koko.maxkit.com.tw 2.6.32-431.el6.i686 #1 SMP Fri Nov 22 00:26:36 UTC 2013 i686
2014-12-08 10:18:07,611 [192.168.1.8SNMPWorkPool.0] INFO  SnmpClientAsync 133
 oid:1.3.6.1.2.1.1.3.0, var=4 days, 18:12:20.49
2014-12-08 10:18:07,612 [192.168.1.8SNMPWorkPool.0] INFO  SnmpClientAsync 133
 oid:1.3.6.1.2.1.1.5.0, var=koko.maxkit.com.tw

Reference

Java實現snmp的get和walk代碼示例

Introduction to snmp4j