用Java代码写一个学生成绩管理系统 要求1：带有图形界面。（20%） 要求2：登录时输入用户名密码。（20%） 要求3：能够录入、查询、修改、删除课程。（20%） 要求4：能够录入、查询、修改、删除学生某个课程的成绩。（20%） 要求5：能够持久化。（20%）

以下是一个简单的Java学生成绩管理系统的代码示例，包括了要求1到要求5的功能。这个示例使用了Swing作为图形界面库，SQLite作为数据库。请注意，这只是一个示例，实际的学生成绩管理系统需要更多的功能和细节处理。

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

public class StudentGradeManagementSystem extends JFrame {
    private static final long serialVersionUID = 1L;
    private Connection conn = null;
    private Statement stmt = null;
    private ResultSet rs = null;
    private String username = "admin";
    private String password = "admin";

    private JLabel nameLabel = new JLabel("用户名:");
    private JLabel passwordLabel = new JLabel("密码:");
    private JTextField nameField = new JTextField(10);
    private JPasswordField passwordField = new JPasswordField(10);
    private JButton loginButton = new JButton("登录");

    private JButton addCourseButton = new JButton("添加课程");
    private JButton deleteCourseButton = new JButton("删除课程");
    private JButton modifyCourseButton = new JButton("修改课程");
    private JButton queryCourseButton = new JButton("查询课程");
    private JButton addGradeButton = new JButton("添加成绩");
    private JButton deleteGradeButton = new JButton("删除成绩");
    private JButton modifyGradeButton = new JButton("修改成绩");
    private JButton queryGradeButton = new JButton("查询成绩");

    public StudentGradeManagementSystem() {
        super("学生成绩管理系统");
        initGUI();
        initDB();
    }

    private void initGUI() {
        JPanel loginPanel = new JPanel(new GridLayout(3, 2));
        loginPanel.add(nameLabel);
        loginPanel.add(nameField);
        loginPanel.add(passwordLabel);
        loginPanel.add(passwordField);
        loginPanel.add(new JPanel());
        loginPanel.add(loginButton);

        JPanel coursePanel = new JPanel(new FlowLayout());
        coursePanel.add(addCourseButton);
        coursePanel.add(deleteCourseButton);
        coursePanel.add(modifyCourseButton);
        coursePanel.add(queryCourseButton);

        JPanel gradePanel = new JPanel(new FlowLayout());
        gradePanel.add(addGradeButton);
        gradePanel.add(deleteGradeButton);
        gradePanel.add(modifyGradeButton);
        gradePanel.add(queryGradeButton);

        JTabbedPane tabbedPane = new JTabbedPane();
        tabbedPane.addTab("登录", loginPanel);
        tabbedPane.addTab("课程管理", coursePanel);
        tabbedPane.addTab("成绩管理", gradePanel);

        add(tabbedPane);

        loginButton.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                String name = nameField.getText();
                String password = new String(passwordField.getPassword());
                if (name.equals(username) && password.equals(password)) {
                    JOptionPane.showMessageDialog(StudentGradeManagementSystem.this, "登录成功");
                } else {
                    JOptionPane.showMessageDialog(StudentGradeManagementSystem.this, "用户名或密码错误");
                }
            }
        });

        queryCourseButton.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                try {
                    rs = stmt.executeQuery("SELECT * FROM course");
                    ResultSetMetaData rsmd = rs.getMetaData();
                    int columnCount = rsmd.getColumnCount();
                    String[] columnNames = new String[columnCount];
                    for (int i = 0; i < columnCount; i++) {
                        columnNames[i] = rsmd.getColumnName(i+1);
                    }
                    Object[][] rowData = new Object[100][columnCount];
                    int rowCount = 0;
                    while (rs.next()) {
                        for (int i = 0; i < columnCount; i++) {
                            rowData[rowCount][i] = rs.getObject(i+1);
                        }
                        rowCount++;
                    }
                    Object[][] data = new Object[rowCount][columnCount];
                    for (int i = 0; i < rowCount; i++) {
                        for (int j = 0; j < columnCount; j++) {
                            data[i][j] = rowData[i][j];
                        }
                    }
                    JTable table = new JTable(data, columnNames);
                    JScrollPane scrollPane = new JScrollPane(table);
                    JOptionPane.showMessageDialog(StudentGradeManagementSystem.this, scrollPane);
                } catch (SQLException ex) {
                    ex.printStackTrace();
                }
            }
        });

        queryGradeButton.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                try {
                    rs = stmt.executeQuery("SELECT * FROM grade");
                    ResultSetMetaData rsmd = rs.getMetaData();
                    int columnCount = rsmd.getColumnCount();
                    String[] columnNames = new String[columnCount];
                    for (int i = 0; i < columnCount; i++) {
                        columnNames[i] = rsmd.getColumnName(i+1);
                    }
                    Object[][] rowData = new Object[100][columnCount];
                    int rowCount = 0;
                    while (rs.next()) {
                        for (int i = 0; i < columnCount; i++) {
                            rowData[rowCount][i] = rs.getObject(i+1);
                        }
                        rowCount++;
                    }
                    Object[][] data = new Object[rowCount][columnCount];
                    for (int i = 0; i < rowCount; i++) {
                        for (int j = 0; j < columnCount; j++) {
                            data[i][j] = rowData[i][j];
                        }
                    }
                    JTable table = new JTable(data, columnNames);
                    JScrollPane scrollPane = new JScrollPane(table);
                    JOptionPane.showMessageDialog(StudentGradeManagementSystem.this, scrollPane);
                } catch (SQLException ex) {
                    ex.printStackTrace();
                }
            }
        });

        addCourseButton.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                String courseName = JOptionPane.showInputDialog(StudentGradeManagementSystem.this, "请输入课程名称");
                if (courseName != null && !courseName.equals("")) {
                    try {
                        stmt.executeUpdate("INSERT INTO course(name) VALUES('" + courseName + "')");
                        JOptionPane.showMessageDialog(StudentGradeManagementSystem.this, "添加成功");
                    } catch (SQLException ex) {
                        ex.printStackTrace();
                    }
                }
            }
        });

        deleteCourseButton.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                String courseId = JOptionPane.showInputDialog(StudentGradeManagementSystem.this, "请输入课程ID");
                if (courseId != null && !courseId.equals("")) {
                    try {
                        stmt.executeUpdate("DELETE FROM course WHERE id=" + courseId);
                        JOptionPane.showMessageDialog(StudentGradeManagementSystem.this, "删除成功");
                    } catch (SQLException ex) {
                        ex.printStackTrace();
                    }
                }
            }
        });

        modifyCourseButton.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                String courseId = JOptionPane.showInputDialog(StudentGradeManagementSystem.this, "请输入课程ID");
                if (courseId != null && !courseId.equals("")) {
                    try {
                        rs = stmt.executeQuery("SELECT * FROM course WHERE id=" + courseId);
                        if (rs.next()) {
                            String courseName = JOptionPane.showInputDialog(StudentGradeManagementSystem.this, "请输入课程名称", rs.getString("name"));
                            stmt.executeUpdate("UPDATE course SET name='" + courseName + "' WHERE id=" + courseId);
                            JOptionPane.showMessageDialog(StudentGradeManagementSystem.this, "修改成功");
                        } else {
                            JOptionPane.showMessageDialog(StudentGradeManagementSystem.this, "未找到该课程");
                        }
                    } catch (SQLException ex) {
                        ex.printStackTrace();
                    }
                }
            }
        });

        addGradeButton.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                String studentId = JOptionPane.showInputDialog(StudentGradeManagementSystem.this, "请输入学生ID");
                String courseId = JOptionPane.showInputDialog(StudentGradeManagementSystem.this, "请输入课程ID");
                String score = JOptionPane.showInputDialog(StudentGradeManagementSystem.this, "请输入成绩");
                if (studentId != null && courseId != null && score != null && !studentId.equals("") && !courseId.equals("") && !score.equals("")) {
                    try {
                        stmt.executeUpdate("INSERT INTO grade(student_id, course_id, score) VALUES('" + studentId + "', '" + courseId + "', '" + score + "')");
                        JOptionPane.showMessageDialog(StudentGradeManagementSystem.this, "添加成功");
                    } catch (SQLException ex) {
                        ex.printStackTrace();
                    }
                }
            }
        });

        deleteGradeButton.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                String gradeId = JOptionPane.showInputDialog(StudentGradeManagementSystem.this, "请输入成绩ID");
                if (gradeId != null && !gradeId.equals("")) {
                    try {
                        stmt.executeUpdate("DELETE FROM grade WHERE id=" + gradeId);
                        JOptionPane.showMessageDialog(StudentGradeManagementSystem.this, "删除成功");
                    } catch (SQLException ex) {
                        ex.printStackTrace();
                    }
                }
            }
        });

        modifyGradeButton.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                String gradeId = JOptionPane.showInputDialog(StudentGradeManagementSystem.this, "请输入成绩ID");
                if (gradeId != null && !gradeId.equals("")) {
                    try {
                        rs = stmt.executeQuery("SELECT * FROM grade WHERE id=" + gradeId);
                        if (rs.next()) {
                            String score = JOptionPane.showInputDialog(StudentGradeManagementSystem.this, "请输入成绩", rs.getString("score"));
                            stmt.executeUpdate("UPDATE grade SET score='" + score + "' WHERE id=" + gradeId);
                            JOptionPane.showMessageDialog(StudentGradeManagementSystem.this, "修改成功");
                        } else {
                            JOptionPane.showMessageDialog(StudentGradeManagementSystem.this, "未找到该成绩");
                        }
                    } catch (SQLException ex) {
                        ex.printStackTrace();
                    }
                }
            }
        });

        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setSize(600, 400);
        setLocationRelativeTo(null);
        setVisible(true);
    }

    private void initDB() {
        try {
            Class.forName("org.sqlite.JDBC");
            conn = DriverManager.getConnection("jdbc:sqlite:student_grade.db");
            stmt = conn.createStatement();
            stmt.executeUpdate("CREATE TABLE IF NOT EXISTS course(id INTEGER PRIMARY KEY AUTOINCREMENT, name TEXT)");
            stmt.executeUpdate("CREATE TABLE IF NOT EXISTS grade(id INTEGER PRIMARY KEY AUTOINCREMENT, student_id INTEGER, course_id INTEGER, score INTEGER)");
        } catch (ClassNotFoundException ex) {
            ex.printStackTrace();
        } catch (SQLException ex) {
            ex.printStackTrace();
        }
    }

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

在这个示例中，我们在登录界面中使用了JTextField和JPasswordField来获取用户名和密码，使用JOptionPane来弹出错误提示框或登录成功提示框。我们使用JTabbedPane来实现多个选项卡界面，其中包括课程管理和成绩管理。在课程管理和成绩管理界面中，我们使用了JButton、JTable和JOptionPane来实现增删改查操作。我们使用JDBC连接了SQLite数据库，并在程序启动时创建了两个表格。