使用java编写程序。（1）设计输入界面，在界面中输入学生信息，保存到数据库； （2）设计删除界面，输入学生学号，如果存在就从数据库中删除； （3）设计更新界面，将第一条学生记录的姓名修改为你的姓名，如果成功则更新显示结果。

好的，下面是一个Java语言实现的示例程序，包括输入界面、删除界面和更新界面，实现了上述三个功能：

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

public class StudentManagementSystem extends JFrame {
    private JLabel studentIdLabel, nameLabel, genderLabel, ageLabel;
    private JTextField studentIdField, nameField, genderField, ageField;
    private JButton addButton, deleteButton, updateButton;
    private Connection conn;
    private Statement stmt;

    public StudentManagementSystem() {
        super("学生信息管理系统");
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setLayout(new GridLayout(5, 2));
        setSize(400, 200);

        studentIdLabel = new JLabel("学号");
        nameLabel = new JLabel("姓名");
        genderLabel = new JLabel("性别");
        ageLabel = new JLabel("年龄");

        studentIdField = new JTextField(10);
        nameField = new JTextField(10);
        genderField = new JTextField(10);
        ageField = new JTextField(10);

        addButton = new JButton("添加");
        deleteButton = new JButton("删除");
        updateButton = new JButton("更新");

        addButton.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                addStudent();
            }
        });

        deleteButton.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                deleteStudent();
            }
        });

        updateButton.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                updateStudent();
            }
        });

        add(studentIdLabel);
        add(studentIdField);
        add(nameLabel);
        add(nameField);
        add(genderLabel);
        add(genderField);
        add(ageLabel);
        add(ageField);
        add(addButton);
        add(deleteButton);
        add(updateButton);

        setVisible(true);

        try {
            Class.forName("com.mysql.jdbc.Driver");
            conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/test", "root", "123456");
            stmt = conn.createStatement();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    private void addStudent() {
        String studentId = studentIdField.getText();
        String name = nameField.getText();
        String gender = genderField.getText();
        String age = ageField.getText();

        try {
            String sql = "INSERT INTO student VALUES ('" + studentId + "', '" + name + "', '" + gender + "', " + age + ")";
            stmt.executeUpdate(sql);
            JOptionPane.showMessageDialog(this, "添加成功！");
        } catch (Exception e) {
            JOptionPane.showMessageDialog(this, "添加失败：" + e.getMessage());
        }
    }

    private void deleteStudent() {
        String studentId = studentIdField.getText();

        try {
            String sql = "SELECT * FROM student WHERE student_id='" + studentId + "'";
            ResultSet rs = stmt.executeQuery(sql);
            if (rs.next()) {
                sql = "DELETE FROM student WHERE student_id='" + studentId + "'";
                stmt.executeUpdate(sql);
                JOptionPane.showMessageDialog(this, "删除成功！");
            } else {
                JOptionPane.showMessageDialog(this, "学号为" + studentId + "的学生不存在！");
            }
        } catch (Exception e) {
            JOptionPane.showMessageDialog(this, "删除失败：" + e.getMessage());
        }
    }

    private void updateStudent() {
        try {
            String sql = "SELECT * FROM student LIMIT 1";
            ResultSet rs = stmt.executeQuery(sql);
            if (rs.next()) {
                String studentId = rs.getString("student_id");
                String name = "你的姓名";
                String gender = rs.getString("gender");
                String age = rs.getString("age");

                sql = "UPDATE student SET name='" + name + "' WHERE student_id='" + studentId + "'";
                stmt.executeUpdate(sql);

                studentIdField.setText(studentId);
                nameField.setText(name);
                genderField.setText(gender);
                ageField.setText(age);

                JOptionPane.showMessageDialog(this, "更新成功！");
            } else {
                JOptionPane.showMessageDialog(this, "学生信息为空！");
            }
        } catch (Exception e) {
            JOptionPane.showMessageDialog(this, "更新失败：" + e.getMessage());
        }
    }

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

该程序使用Java Swing库来设计GUI界面，使用JDBC连接MySQL数据库来实现学生信息的添加、删除和更新功能。在运行程序之前，请确保已经安装了MySQL数据库，并且在MySQL中创建了名为test的数据库和名为student的表，表结构如下：

CREATE TABLE student (
    student_id VARCHAR(10) PRIMARY KEY,
    name VARCHAR(20),
    gender VARCHAR(2),
    age INT
);

程序中的JDBC连接字符串和数据库用户名、密码需要根据实际情况进行修改。