运用Java 实现学生管理系统，该系统具备添加元素、删除元素、修改元素、查询元素的功能。 要求进行界面设计，通过输入数字，调用方法实现对应功能。

好的，那我来为您介绍一下实现学生管理系统的基本思路：

1. 定义学生类，包括学生ID、姓名、年龄、性别、成绩等属性；
2. 定义学生管理类，包括添加学生、删除学生、修改学生、查询学生等方法；
3. 利用Java Swing组件实现学生管理系统的界面设计，包括添加学生的文本框、按钮、表格等界面元素；
4. 在界面中添加事件监听器，根据用户输入的数字调用对应的方法实现相应的功能。

下面是一个简单的示例代码，您可以参考一下：

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.table.*;

public class StudentManagementSystem extends JFrame implements ActionListener {

    private JLabel titleLabel;
    private JLabel idLabel;
    private JLabel nameLabel;
    private JLabel ageLabel;
    private JLabel genderLabel;
    private JLabel gradeLabel;
    private JTextField idField;
    private JTextField nameField;
    private JTextField ageField;
    private JTextField genderField;
    private JTextField gradeField;
    private JButton addButton;
    private JButton deleteButton;
    private JButton updateButton;
    private JButton searchButton;
    private JTable table;
    private DefaultTableModel model;

    public StudentManagementSystem() {
        super("学生管理系统");
        setSize(600, 400);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setLayout(new BorderLayout());

        // 标题
        titleLabel = new JLabel("学生管理系统", JLabel.CENTER);
        add(titleLabel, BorderLayout.NORTH);

        // 表格
        model = new DefaultTableModel();
        model.addColumn("学号");
        model.addColumn("姓名");
        model.addColumn("年龄");
        model.addColumn("性别");
        model.addColumn("成绩");
        table = new JTable(model);
        add(new JScrollPane(table), BorderLayout.CENTER);

        // 添加学生
        JPanel addPanel = new JPanel(new GridLayout(6, 2));
        idLabel = new JLabel("学号：");
        idField = new JTextField();
        nameLabel = new JLabel("姓名：");
        nameField = new JTextField();
        ageLabel = new JLabel("年龄：");
        ageField = new JTextField();
        genderLabel = new JLabel("性别：");
        genderField = new JTextField();
        gradeLabel = new JLabel("成绩：");
        gradeField = new JTextField();
        addButton = new JButton("添加");
        addButton.addActionListener(this);
        addPanel.add(idLabel);
        addPanel.add(idField);
        addPanel.add(nameLabel);
        addPanel.add(nameField);
        addPanel.add(ageLabel);
        addPanel.add(ageField);
        addPanel.add(genderLabel);
        addPanel.add(genderField);
        addPanel.add(gradeLabel);
        addPanel.add(gradeField);
        addPanel.add(new JPanel());
        addPanel.add(addButton);
        add(addPanel, BorderLayout.SOUTH);

        // 删除学生
        deleteButton = new JButton("删除");
        deleteButton.addActionListener(this);
        add(deleteButton, BorderLayout.WEST);

        // 修改学生
        updateButton = new JButton("修改");
        updateButton.addActionListener(this);
        add(updateButton, BorderLayout.EAST);

        // 查询学生
        searchButton = new JButton("查询");
        searchButton.addActionListener(this);
        add(searchButton, BorderLayout.SOUTH);

        setVisible(true);
    }

    /**
     * 添加学生
     */
    private void addStudent() {
        String id = idField.getText();
        String name = nameField.getText();
        int age = Integer.parseInt(ageField.getText());
        String gender = genderField.getText();
        double grade = Double.parseDouble(gradeField.getText());
        Object[] row = { id, name, age, gender, grade };
        model.addRow(row);
    }

    /**
     * 删除学生
     */
    private void deleteStudent() {
        int row = table.getSelectedRow();
        if (row >= 0) {
            model.removeRow(row);
        } else {
            JOptionPane.showMessageDialog(this, "请选择要删除的学生");
        }
    }

    /**
     * 修改学生
     */
    private void updateStudent() {
        int row = table.getSelectedRow();
        if (row >= 0) {
            String id = idField.getText();
            String name = nameField.getText();
            int age = Integer.parseInt(ageField.getText());
            String gender = genderField.getText();
            double grade = Double.parseDouble(gradeField.getText());
            table.setValueAt(id, row, 0);
            table.setValueAt(name, row, 1);
            table.setValueAt(age, row, 2);
            table.setValueAt(gender, row, 3);
            table.setValueAt(grade, row, 4);
        } else {
            JOptionPane.showMessageDialog(this, "请选择要修改的学生");
        }
    }

    /**
     * 查询学生
     */
    private void searchStudent() {
        String keyword = JOptionPane.showInputDialog(this, "请输入要查询的关键字");
        if (keyword != null && !keyword.trim().equals("")) {
            for (int i = 0; i < model.getRowCount(); i++) {
                for (int j = 0; j < model.getColumnCount(); j++) {
                    String value = model.getValueAt(i, j).toString();
                    if (value.contains(keyword)) {
                        table.setRowSelectionInterval(i, i);
                        return;
                    }
                }
            }
            JOptionPane.showMessageDialog(this, "没有找到符合条件的学生");
        }
    }

    @Override
    public void actionPerformed(ActionEvent e) {
        if (e.getSource() == addButton) {
            addStudent();
        } else if (e.getSource() == deleteButton) {
            deleteStudent();
        } else if (e.getSource() == updateButton) {
            updateStudent();
        } else if (e.getSource() == searchButton) {
            searchStudent();
        }
    }

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

}

以上代码仅供参考，您可以根据需求进行修改和完善。