无法找到或加载 snmpAgent 的主类（使用 snmp4j）

Question

我一直在尝试使用 snmp 管理器向 snmp 代理发送请求。它们基于 snmp4j，代码在http://www.jitendrazaa.com/blog/java/snmp/creating-snmp-agent-server-in-java-using-snmp4j/

SNMPAgent.java

package com.G2.SNMP.Server;

import java.io.File;
import java.io.IOException;

import org.snmp4j.TransportMapping;
import org.snmp4j.agent.BaseAgent;
import org.snmp4j.agent.CommandProcessor;
import org.snmp4j.agent.DuplicateRegistrationException;
import org.snmp4j.agent.MOGroup;
import org.snmp4j.agent.ManagedObject;
import org.snmp4j.agent.mo.MOTableRow;
import org.snmp4j.agent.mo.snmp.RowStatus;
import org.snmp4j.agent.mo.snmp.SnmpCommunityMIB;
import org.snmp4j.agent.mo.snmp.SnmpNotificationMIB;
import org.snmp4j.agent.mo.snmp.SnmpTargetMIB;
import org.snmp4j.agent.mo.snmp.StorageType;
import org.snmp4j.agent.mo.snmp.VacmMIB;
import org.snmp4j.agent.security.MutableVACM;
import org.snmp4j.mp.MPv3;
import org.snmp4j.security.SecurityLevel;
import org.snmp4j.security.SecurityModel;
import org.snmp4j.security.USM;
import org.snmp4j.smi.Address;
import org.snmp4j.smi.GenericAddress;
import org.snmp4j.smi.Integer32;
import org.snmp4j.smi.OID;
import org.snmp4j.smi.OctetString;
import org.snmp4j.smi.Variable;
import org.snmp4j.transport.TransportMappings;

public class SNMPAgent extends BaseAgent {

    private String address;

    /**
     *
     * @param address
     * @throws IOException
     */
    public SNMPAgent(String address) throws IOException {

        /**
         * Creates a base agent with boot-counter, config file, and a
         * CommandProcessor for processing SNMP requests. Parameters:
         * "bootCounterFile" - a file with serialized boot-counter information
         * (read/write). If the file does not exist it is created on shutdown of
         * the agent. "configFile" - a file with serialized configuration
         * information (read/write). If the file does not exist it is created on
         * shutdown of the agent. "commandProcessor" - the CommandProcessor
         * instance that handles the SNMP requests.
         */
        super(new File("conf.agent"), new File("bootCounter.agent"),
                new CommandProcessor(
                        new OctetString(MPv3.createLocalEngineID())));
        this.address = address;
    }

    /**
     * Adds community to security name mappings needed for SNMPv1 and SNMPv2c.
     */
    @Override
    protected void addCommunities(SnmpCommunityMIB communityMIB) {
        Variable[] com2sec = new Variable[] { new OctetString("public"),
                new OctetString("cpublic"), // security name
                getAgent().getContextEngineID(), // local engine ID
                new OctetString("public"), // default context name
                new OctetString(), // transport tag
                new Integer32(StorageType.nonVolatile), // storage type
                new Integer32(RowStatus.active) // row status
        };
        SnmpCommunityMIB.SnmpCommunityEntryRow row = communityMIB.getSnmpCommunityEntry().createRow(
                new OctetString("public2public").toSubIndex(true), com2sec);
        communityMIB.getSnmpCommunityEntry().addRow(row);

    }

    /**
     * Adds initial notification targets and filters.
     */
    @Override
    protected void addNotificationTargets(SnmpTargetMIB arg0,
            SnmpNotificationMIB arg1) {
        // TODO Auto-generated method stub

    }

    /**
     * Adds all the necessary initial users to the USM.
     */
    @Override
    protected void addUsmUser(USM arg0) {
        // TODO Auto-generated method stub

    }

    /**
     * Adds initial VACM configuration.
     */
    @Override
    protected void addViews(VacmMIB vacm) {
        vacm.addGroup(SecurityModel.SECURITY_MODEL_SNMPv2c, new OctetString(
                "cpublic"), new OctetString("v1v2group"),
                StorageType.nonVolatile);

        vacm.addAccess(new OctetString("v1v2group"), new OctetString("public"),
                SecurityModel.SECURITY_MODEL_ANY, SecurityLevel.NOAUTH_NOPRIV,
                MutableVACM.VACM_MATCH_EXACT, new OctetString("fullReadView"),
                new OctetString("fullWriteView"), new OctetString(
                        "fullNotifyView"), StorageType.nonVolatile);

        vacm.addViewTreeFamily(new OctetString("fullReadView"), new OID("1.3"),
                new OctetString(), VacmMIB.vacmViewIncluded,
                StorageType.nonVolatile);

    }

    /**
     * Unregister the basic MIB modules from the agent's MOServer.
     */
    @Override
    protected void unregisterManagedObjects() {
        // TODO Auto-generated method stub

    }

    /**
     * Register additional managed objects at the agent's server.
     */
    @Override
    protected void registerManagedObjects() {
        // TODO Auto-generated method stub

    }

    protected void initTransportMappings() throws IOException {
        transportMappings = new TransportMapping[1];
        Address addr = GenericAddress.parse(address);
        TransportMapping tm = TransportMappings.getInstance()
                .createTransportMapping(addr);
        transportMappings[0] = tm;
    }

    /**
     * Start method invokes some initialization methods needed to start the
     * agent
     *
     * @throws IOException
     */
    public void start() throws IOException {

        init();
        // This method reads some old config from a file and causes
        // unexpected behavior.
        // loadConfig(ImportModes.REPLACE_CREATE);
        addShutdownHook();
        getServer().addContext(new OctetString("public"));
        finishInit();
        run();
        sendColdStartNotification();
    }

    /**
     * Clients can register the MO they need
     */
    public void registerManagedObject(ManagedObject mo) {
        try {
            server.register(mo, null);
        } catch (DuplicateRegistrationException ex) {
            throw new RuntimeException(ex);
        }
    }

    public void unregisterManagedObject(MOGroup moGroup) {
        moGroup.unregisterMOs(server, getContext(moGroup));
    }

}

snmp 代理类使用的托管对象： MOCreator.java

package com.G2.SNMP.Server;

import org.snmp4j.agent.mo.MOAccessImpl;
import org.snmp4j.agent.mo.MOScalar;
import org.snmp4j.smi.OID;
import org.snmp4j.smi.OctetString;
import org.snmp4j.smi.Variable;

/**
 * This class creates and returns ManagedObjects
 * @author Shiva
 *
 */
public class MOCreator {
    public static MOScalar createReadOnly(OID oid,Object value ){
        return new MOScalar(oid,
                MOAccessImpl.ACCESS_READ_ONLY,
                getVariable(value));
    }

    private static Variable getVariable(Object value) {
        if(value instanceof String) {
            return new OctetString((String)value);
        }
        throw new IllegalArgumentException("Unmanaged Type: " + value.getClass());
    }

}

SNMPManager.java

package com.G2.SNMP.client;

import java.io.IOException;

import org.snmp4j.CommunityTarget;
import org.snmp4j.PDU;
import org.snmp4j.Snmp;
import org.snmp4j.Target;
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 SNMPManager {

Snmp snmp = null;
String address = null;

/**
* Constructor
* @param add
*/
public SNMPManager(String add)
{
address = add;
}

public static void main(String[] args) throws IOException {
/**
* Port 161 is used for Read and Other operations
* Port 162 is used for the trap generation
*/
SNMPManager client = new SNMPManager("udp:127.0.0.1/161");
client.start();
/**
* OID - .1.3.6.1.2.1.1.1.0 => SysDec
* OID - .1.3.6.1.2.1.1.5.0 => SysName
* => MIB explorer will be usefull here, as discussed in previous article
*/
String sysDescr = client.getAsString(new OID(".1.3.6.1.2.1.1.1.0"));
System.out.println(sysDescr);
}

/**
* Start the Snmp session. If you forget the listen() method you will not
* get any answers because the communication is asynchronous
* and the listen() method listens for answers.
* @throws IOException
*/
public void start() throws IOException {
TransportMapping transport = new DefaultUdpTransportMapping();
snmp = new Snmp(transport);
// Do not forget this line!
transport.listen();
}

/**
* Method which takes a single OID and returns the response from the agent as a String.
* @param oid
* @return
* @throws IOException
*/
public String getAsString(OID oid) throws IOException {
ResponseEvent event = get(new OID[] { oid });
return event.getResponse().get(0).getVariable().toString();
}

/**
* This method is capable of handling multiple OIDs
* @param oids
* @return
* @throws IOException
*/
public ResponseEvent get(OID oids[]) throws IOException {
PDU pdu = new PDU();
for (OID oid : oids) {
pdu.add(new VariableBinding(oid));
}
pdu.setType(PDU.GET);
ResponseEvent event = snmp.send(pdu, getTarget(), null);
if(event != null) {
return event;
}
throw new RuntimeException("GET timed out");
}

/**
* This method returns a Target, which contains information about
* where the data should be fetched and how.
* @return
*/
private Target getTarget() {
Address targetAddress = GenericAddress.parse(address);
CommunityTarget target = new CommunityTarget();
target.setCommunity(new OctetString("public"));
target.setAddress(targetAddress);
target.setRetries(2);
target.setTimeout(1500);
target.setVersion(SnmpConstants.version2c);
return target;
}

}

TestSNMPAgent.java

package com.G2.SNMP.Server;

import java.io.IOException;

import org.snmp4j.smi.OID;

import com.G2.SNMP.client.SNMPManager;

public class TestSNMPAgent {

    static final OID sysDescr = new OID(".1.3.6.1.2.1.1.1.0");

    public static void main(String[] args) throws IOException {
        TestSNMPAgent client = new TestSNMPAgent("udp:127.0.0.1/161");
        client.init();
    }

    SNMPAgent agent = null;
    /**
     * This is the client which we have created earlier
     */
    SNMPManager client = null;

    String address = null;

    /**
     * Constructor
     *
     * @param add
     */
    public TestSNMPAgent(String add) {
        address = add;
    }

    private void init() throws IOException {
        agent = new SNMPAgent("0.0.0.0/2001");
        agent.start();

        // Since BaseAgent registers some MIBs by default we need to unregister
        // one before we register our own sysDescr. Normally you would
        // override that method and register the MIBs that you need
        agent.unregisterManagedObject(agent.getSnmpv2MIB());

        // Register a system description, use one from you product environment
        // to test with
        agent.registerManagedObject(MOCreator.createReadOnly(sysDescr,
                "This Description is set By ShivaSoft"));

        // Setup the client to use our newly started agent
        client = new SNMPManager("udp:127.0.0.1/2001");
        client.start();
        // Get back Value which is set
        System.out.println(client.getAsString(sysDescr));
    }

}

这就是我编译代码的方式（我已经有了 snmp4j 和 api 的代理 .jar 文件）

javac -d 。 -cp "snmp4j-2.5.0.jar:snmp4j-agent-2.5.0.jar" *.java

这就是我执行代码的方式

java -cp "snmp4j-2.5.0.jar:snmp4j-agent-2.5.0.jar" com.G2.SNMP.Server.TestSNMPAgent

这里的问题是当我尝试执行它时，我总是得到这个错误

错误：无法找到或加载主类 com.G2.SNMP.Server.TestSNMPAgent

可能是我执行它的方式有一些错误，欢迎任何帮助！感谢你！

Answer 1

要使用 .jar 库执行，语法为：

java -cp one.jar:two.jar:.文件运行

所以 ：

java -cp "snmp4j-2.5.0.jar:snmp4j-agent-2.5.0.jar:." com.G2.SNMP.Server.TestSNMPAgent

插入

java -cp "snmp4j-2.5.0.jar:snmp4j-agent-2.5.0.jar" com.G2.SNMP.Server.TestSNMPAgent