用Java编写一个资产管理系统窗体，子菜单包括系统管理，资产信息管理，人员信息管理，资产领用，资产归还，资产报废。 其中系统管理下拉菜单内容为类别管理，打开，关闭，退出。类别管理点击打开后，跳出窗口，内容为系统管理表，表格连接MySQL数据库，窗口有获取新编号，增加，修改，删除，清空，退出五个按钮。 资产信息管理下拉菜单内容为添加，修改，删除，查询。人员信息管理下拉菜单内容为人员信息修改，人员信息查询，人员信息删除，查询人员信息。查询人员信息又分为查询所有和按编号查询。 资产领用下拉菜单内容为资产领用管理，领用信息查询。 资产领用管理连接mysql数据库中的表格，窗口内容为资产名称，领用人员，用途，备注，四个内容框的填写。下面有领用和清空两个按钮。 领用信息查询点击打开为MySQL表中内容。 资产归还下拉菜单内容为资产归还管理，归还信息查询。 资产归还管理连接mysql数据库中的表格，窗口内容为资产名称，操作人员，归还原因，备注，四个内容框的填写。下面有领用和清空两个按钮。 归还信息查询点击打开为MySQL表中内容。 资产报废下拉菜单内容为资产报废管理，报废信息查询。 资产报废管理连接mysql数据库中的表格，窗口内容为资产名称，操作人员，报废原因，备注，四个内容框的填写。下面有领用和清空两个按钮。 报废信息查询点击打开为MySQL表中内容。

以下是一个简单的资产管理系统窗体的示例代码，其中包括菜单栏和子菜单，并添加了一些按钮和文本框。请注意，以下代码仅作为示例，您需要根据具体需求进行修改和完善。

import java.awt.BorderLayout;
import java.awt.EventQueue;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.JTextField;
import javax.swing.border.EmptyBorder;
import javax.swing.table.DefaultTableModel;

public class AssetManagementSystem extends JFrame {

    private JPanel contentPane;
    private JTextField textFieldAssetName;
    private JTextField textFieldUserName;
    private JTextField textFieldPurpose;
    private JTextField textFieldRemarks;
    private JTextField textFieldReturnReason;
    private JTextField textFieldScrapReason;
    private JTable table;
    private DefaultTableModel model;
    private Connection con;
    private Statement stmt;
    private ResultSet rs;
    
    /**
     * Launch the application.
     */
    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            public void run() {
                try {
                    AssetManagementSystem frame = new AssetManagementSystem();
                    frame.setVisible(true);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
    }

    /**
     * Create the frame.
     */
    public AssetManagementSystem() {
        setTitle("Asset Management System");
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setBounds(100, 100, 800, 600);
        
        // 创建菜单栏
        JMenuBar menuBar = new JMenuBar();
        setJMenuBar(menuBar);
        
        // 创建子菜单
        JMenu systemMenu = new JMenu("System Management");
        menuBar.add(systemMenu);
        
        JMenuItem categoryMenuItem = new JMenuItem("Category Management");
        categoryMenuItem.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                // 打开类别管理窗口
                openCategoryWindow();
            }
        });
        systemMenu.add(categoryMenuItem);
        
        JMenuItem openMenuItem = new JMenuItem("Open");
        systemMenu.add(openMenuItem);
        
        JMenuItem closeMenuItem = new JMenuItem("Close");
        systemMenu.add(closeMenuItem);
        
        JMenuItem exitMenuItem = new JMenuItem("Exit");
        exitMenuItem.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                // 退出程序
                System.exit(0);
            }
        });
        systemMenu.add(exitMenuItem);
        
        JMenu assetMenu = new JMenu("Asset Information Management");
        menuBar.add(assetMenu);
        
        JMenuItem addAssetMenuItem = new JMenuItem("Add Asset");
        assetMenu.add(addAssetMenuItem);
        
        JMenuItem modifyAssetMenuItem = new JMenuItem("Modify Asset");
        assetMenu.add(modifyAssetMenuItem);
        
        JMenuItem deleteAssetMenuItem = new JMenuItem("Delete Asset");
        assetMenu.add(deleteAssetMenuItem);
        
        JMenuItem queryAssetMenuItem = new JMenuItem("Query Asset");
        assetMenu.add(queryAssetMenuItem);
        
        JMenu personnelMenu = new JMenu("Personnel Information Management");
        menuBar.add(personnelMenu);
        
        JMenuItem modifyPersonnelMenuItem = new JMenuItem("Modify Personnel");
        personnelMenu.add(modifyPersonnelMenuItem);
        
        JMenuItem queryPersonnelMenuItem = new JMenuItem("Query Personnel");
        personnelMenu.add(queryPersonnelMenuItem);
        
        JMenuItem deletePersonnelMenuItem = new JMenuItem("Delete Personnel");
        personnelMenu.add(deletePersonnelMenuItem);
        
        JMenuItem queryAllPersonnelMenuItem = new JMenuItem("Query All Personnel");
        personnelMenu.add(queryAllPersonnelMenuItem);
        
        JMenu takeMenu = new JMenu("Asset Take Management");
        menuBar.add(takeMenu);
        
        JMenuItem takeMenuItem = new JMenuItem("Asset Take");
        takeMenu.add(takeMenuItem);
        
        JMenuItem queryTakeMenuItem = new JMenuItem("Query Asset Take");
        takeMenu.add(queryTakeMenuItem);
        
        JMenu returnMenu = new JMenu("Asset Return Management");
        menuBar.add(returnMenu);
        
        JMenuItem returnMenuItem = new JMenuItem("Asset Return");
        returnMenu.add(returnMenuItem);
        
        JMenuItem queryReturnMenuItem = new JMenuItem("Query Asset Return");
        returnMenu.add(queryReturnMenuItem);
        
        JMenu scrapMenu = new JMenu("Asset Scrap Management");
        menuBar.add(scrapMenu);
        
        JMenuItem scrapMenuItem = new JMenuItem("Asset Scrap");
        scrapMenu.add(scrapMenuItem);
        
        JMenuItem queryScrapMenuItem = new JMenuItem("Query Asset Scrap");
        scrapMenu.add(queryScrapMenuItem);
        
        // 创建内容面板
        contentPane = new JPanel();
        contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
        contentPane.setLayout(new BorderLayout(0, 0));
        setContentPane(contentPane);
        
        // 创建表格和滚动条
        String[] columnNames = {"ID", "Asset Name", "User Name", "Purpose", "Remarks"};
        model = new DefaultTableModel(columnNames, 0);
        table = new JTable(model);
        JScrollPane scrollPane = new JScrollPane(table);
        contentPane.add(scrollPane, BorderLayout.CENTER);
        
        // 创建底部面板和按钮
        JPanel bottomPanel = new JPanel();
        contentPane.add(bottomPanel, BorderLayout.SOUTH);
        
        JButton takeButton = new JButton("Take");
        takeButton.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                // 资产领用操作
                takeAsset();
            }
        });
        bottomPanel.add(takeButton);
        
        JButton clearButton = new JButton("Clear");
        clearButton.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                // 清空文本框
                clearFields();
            }
        });
        bottomPanel.add(clearButton);
        
        JLabel lblAssetName = new JLabel("Asset Name:");
        bottomPanel.add(lblAssetName);
        
        textFieldAssetName = new JTextField();
        bottomPanel.add(textFieldAssetName);
        textFieldAssetName.setColumns(10);
        
        JLabel lblUserName = new JLabel("User Name:");
        bottomPanel.add(lblUserName);
        
        textFieldUserName = new JTextField();
        bottomPanel.add(textFieldUserName);
        textFieldUserName.setColumns(10);
        
        JLabel lblPurpose = new JLabel("Purpose:");
        bottomPanel.add(lblPurpose);
        
        textFieldPurpose = new JTextField();
        bottomPanel.add(textFieldPurpose);
        textFieldPurpose.setColumns(10);
        
        JLabel lblRemarks = new JLabel("Remarks:");
        bottomPanel.add(lblRemarks);
        
        textFieldRemarks = new JTextField();
        bottomPanel.add(textFieldRemarks);
        textFieldRemarks.setColumns(10);
        
        JLabel lblReturnReason = new JLabel("Return Reason:");
        bottomPanel.add(lblReturnReason);
        
        textFieldReturnReason = new JTextField();
        bottomPanel.add(textFieldReturnReason);
        textFieldReturnReason.setColumns(10);
        
        JLabel lblScrapReason = new JLabel("Scrap Reason:");
        bottomPanel.add(lblScrapReason);
        
        textFieldScrapReason = new JTextField();
        bottomPanel.add(textFieldScrapReason);
        textFieldScrapReason.setColumns(10);
        
        // 建立数据库连接
        try {
            Class.forName("com.mysql.jdbc.Driver");
            con = DriverManager.getConnection("jdbc:mysql://localhost:3306/asset", "root", "password");
            stmt = con.createStatement();
        } catch (ClassNotFoundException ex) {
            ex.printStackTrace();
        } catch (SQLException ex) {
            ex.printStackTrace();
        }
    }
    
    // 打开类别管理窗口
    private void openCategoryWindow() {
        // TODO: 实现类别管理窗口
    }
    
    // 清空文本框
    private void clearFields() {
        textFieldAssetName.setText("");
        textFieldUserName.setText("");
        textFieldPurpose.setText("");
        textFieldRemarks.setText("");
        textFieldReturnReason.setText("");
        textFieldScrapReason.setText("");
    }
    
    // 资产领用操作
    private void takeAsset() {
        try {
            String assetName = textFieldAssetName.getText();
            String userName = textFieldUserName.getText();
            String purpose = textFieldPurpose.getText();
            String remarks = textFieldRemarks.getText();
            String sql = "INSERT INTO take (asset_name, user_name, purpose, remarks) VALUES ('" + assetName + "', '" + userName + "', '" + purpose + "', '" + remarks + "')";
            stmt.executeUpdate(sql);
            JOptionPane.showMessageDialog(this, "Asset Taken Successfully");
            clearFields();
        } catch (SQLException ex) {
            ex.printStackTrace();
        }
    }
}

请注意，以上代码仅用于示例，您需要根据具体需求进行修改和完善。特别是，建议将数据库连接和操作分离到单独的类中，以提高代码的可维护性。