使用snmp4j绘制网络拓扑的代码

要使用 SNMP4J 绘制网络拓扑，您需要了解 SNMP4J 库和 Java 图形用户界面（GUI）编程。以下是一个简单的示例代码：

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import org.snmp4j.*;
import org.snmp4j.smi.*;
import org.snmp4j.transport.*;
import org.snmp4j.util.*;

public class NetworkTopology extends JFrame implements ActionListener {
    private static final long serialVersionUID = 1L;
    private JTextField textField;
    private JButton button;
    private JPanel panel;

    public NetworkTopology() {
        super("Network Topology");

        textField = new JTextField(20);
        button = new JButton("Get Topology");
        panel = new JPanel();

        button.addActionListener(this);

        panel.add(textField);
        panel.add(button);

        add(panel);

        setSize(300, 100);
        setLocationRelativeTo(null);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setVisible(true);
    }

    public static void main(String[] args) {
        new NetworkTopology();
    }

    public void actionPerformed(ActionEvent e) {
        if (e.getSource() == button) {
            DefaultTreeModel model = new DefaultTreeModel(new DefaultMutableTreeNode("Network Topology"));
            Snmp snmp = null;
            try {
                TransportMapping<? extends Address> transport = new DefaultUdpTransportMapping();
                snmp = new Snmp(transport);
                transport.listen();

                PDU pdu = new PDU();
                pdu.setType(PDU.GETNEXT);
                pdu.add(new VariableBinding(new OID("1")));

                boolean finished = false;
                while (!finished) {
                    ResponseEvent response = snmp.send(pdu, new CommunityTarget(new UdpAddress(textField.getText()), new OctetString("public")));
                    if (response.getResponse() == null) {
                        finished = true;
                    } else {
                        VariableBinding vb = response.getResponse().get(0);
                        if (vb.getOid().startsWith(new OID("1"))) {
                            model.insertNodeInto(new DefaultMutableTreeNode(vb.getVariable().toString()), (MutableTreeNode) model.getRoot(), 0);
                            pdu.setRequestID(new Integer32(0));
                            pdu.set(0, vb);
                        } else {
                            finished = true;
                        }
                    }
                }
            } catch (Exception ex) {
                ex.printStackTrace();
            } finally {
                if (snmp != null) {
                    try {
                        snmp.close();
                    } catch (Exception ex) {
                        ex.printStackTrace();
                    }
                }
            }

            JTree tree = new JTree(model);
            JScrollPane scrollPane = new JScrollPane(tree);
            panel.removeAll();
            panel.add(scrollPane);
            revalidate();
            repaint();
        }
    }
}

该代码使用 SNMP4J 库检索网络拓扑。当用户单击 "Get Topology" 按钮时，它将使用 SNMP 协议检索网络拓扑，并将其显示在树中。您需要替换 "textField.getText()" 中的 IP 地址。