如何在snmp4j中实现二进制(b)变量

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 SNMPExample {
    public static void main(String[] args) {
        try {
            // 创建SNMP管理器
            TransportMapping<? extends Address> transport = new DefaultUdpTransportMapping();
            Snmp snmp = new Snmp(transport);
            transport.listen();

            // 创建目标对象
            Address targetAddress = GenericAddress.parse("udp:127.0.0.1/161");
            CommunityTarget target = new CommunityTarget();
            target.setAddress(targetAddress);
            target.setCommunity(new OctetString("public"));
            target.setVersion(SnmpConstants.version2c);

            // 创建OID对象
            OID oid = new OID("1.3.6.1.2.1.2.2.1.7.1"); // 示例OID，表示接口1的状态

            // 创建变量绑定
            VariableBinding varBinding = new VariableBinding(oid);

            // 创建PDU对象
            PDU pdu = new PDU();
            pdu.add(varBinding);
            pdu.setType(PDU.GET);

            // 发送SNMP请求
            ResponseEvent response = snmp.send(pdu, target, null);

            // 处理SNMP响应
            if (response.getResponse() != null) {
                PDU responsePDU = response.getResponse();
                if (responsePDU.getErrorStatus() == PDU.noError) {
                    VariableBinding[] varBindings = responsePDU.getVariableBindings();
                    if (varBindings != null && varBindings.length > 0) {
                        VariableBinding varBinding = varBindings[0];
                        OID responseOID = varBinding.getOid();
                        OctetString responseValue = (OctetString) varBinding.getVariable();
                        System.out.println("OID: " + responseOID.toString());
                        System.out.println("Value: " + responseValue.toHexString());
                    }
                } else {
                    System.out.println("Error: " + responsePDU.getErrorStatusText());
                }
            } else {
                System.out.println("No response received.");
            }

            // 关闭SNMP管理器
            snmp.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}