java学生成绩管理系统

使用java swing 和 jdbc 技术 管理学生信息

• 学生成绩管理系统
• 一，总体架构
• 二、controller层的编写
• 三、pojo层的编写
• 四，view层的编写
• 五，数据库的连接
• 六，启动程序

一共五个包

包含select及update两个核心类的编写，以后的按钮绑定的事件会使用其中的函数。
select类如下

package Controller;

import POJO.Student;
import POJO.StudentCourse;
import POJO.inputStudentInfo;
import Utils.DbConnection;

import java.io.*;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;


public class Select {
    // 查询执行行数
    public int userloginSelect(String sql) {
        ResultSet resultSet = DbConnection.query(sql);
        int a = 0;
        try {
            while (resultSet.next()) {
                a = resultSet.getInt(1);
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return a;
    }

    //查询全部的学生
    public Object[][] selectStudentAll(){
        String sql = "SELECT * FROM student ";
        System.out.println(sql);
        Connection conn = DbConnection.getConnection();
        PreparedStatement stmt = null;
        ResultSet rs = null;
        ArrayList list = new ArrayList();
        try {
            stmt = (PreparedStatement) conn.prepareStatement(sql);
            rs = stmt.executeQuery();
            while (rs.next()) {
                Student student = new Student();
                student.setID(rs.getInt(1));
                student.setName(rs.getString(2));
                student.setSex(rs.getString(3));
                student.setDateOfBirth(rs.getString(4));
                student.setStudentID(rs.getString(5));
                list.add(student);
            }
        } catch (SQLException e1) {
            e1.printStackTrace();
        } finally {
            try {
                DbConnection.colse(rs, stmt, conn);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
        Object[][] objects = new Object[list.size()][5];
        for (int i = 0; i < list.size(); i++) {
            objects[i][0] = list.get(i).getID();
            objects[i][1] = list.get(i).getName();
            objects[i][2] = list.get(i).getSex();
            objects[i][3] = list.get(i).getDateOfBirth();
            objects[i][4] = list.get(i).getStudentID();
        }
        return objects;
    }

    //根据姓名查询学生信息
    public Object[][] selectStudentByName(String name){
        String sql = "SELECT * FROM student where  name = '"+name+"'";
        Connection conn = DbConnection.getConnection();
        PreparedStatement stmt = null;
        ResultSet rs = null;
        ArrayList list = new ArrayList();
        try {
            stmt = (PreparedStatement) conn.prepareStatement(sql);
            rs = stmt.executeQuery();
            while (rs.next()) {
                Student student = new Student();
                student.setID(rs.getInt(1));
                student.setName(rs.getString(2));
                student.setSex(rs.getString(3));
                student.setDateOfBirth(rs.getString(4));
                student.setStudentID(rs.getString(5));
                list.add(student);
            }
        } catch (SQLException e1) {
            e1.printStackTrace();
        } finally {
            try {
                DbConnection.colse(rs, stmt, conn);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
        Object[][] objects = new Object[list.size()][5];
        for (int i = 0; i < list.size(); i++) {
            objects[i][0] = list.get(i).getID();
            objects[i][1] = list.get(i).getName();
            objects[i][2] = list.get(i).getSex();
            objects[i][3] = list.get(i).getDateOfBirth();
            objects[i][4] = list.get(i).getStudentID();
        }
        return objects;
    }


    //查询全部的学生对应的成绩
    public Object[][] selectStudentCourseAll(){
        String sql = "SELECT * FROM studentcourse ";
        System.out.println(sql);
        Connection conn = DbConnection.getConnection();
        PreparedStatement stmt = null;
        ResultSet rs = null;
        ArrayList list = new ArrayList<>();
        try {
            stmt = (PreparedStatement) conn.prepareStatement(sql);
            rs = stmt.executeQuery();
            while (rs.next()) {
                StudentCourse student = new StudentCourse();
                student.setId(rs.getInt(1));
                student.setStudentName(rs.getString(2));
                student.setCourseName(rs.getString(3));
                student.setCourseGrade(rs.getInt(4));
                student.setStudentID(rs.getString(5));
                list.add(student);
            }
        } catch (SQLException e1) {
            e1.printStackTrace();
        } finally {
            try {
                DbConnection.colse(rs, stmt, conn);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
        Object[][] objects = new Object[list.size()][5];
        for (int i = 0; i < list.size(); i++) {
            objects[i][0] = list.get(i).getId();
            objects[i][1] = list.get(i).getStudentName();
            objects[i][2] = list.get(i).getCourseName();
            objects[i][3] = list.get(i).getCourseGrade();
            objects[i][4] = list.get(i).getStudentID();
        }
        return objects;
    }

    //根据课程查询成绩信息
    public Object[][] selectStudentCourseByCourseName(String name){
        String sql = "SELECT * FROM studentcourse  where  course_name = '"+name+"'";
        System.out.println(sql);
        Connection conn = DbConnection.getConnection();
        PreparedStatement stmt = null;
        ResultSet rs = null;
        ArrayList list = new ArrayList<>();
        try {
            stmt = (PreparedStatement) conn.prepareStatement(sql);
            rs = stmt.executeQuery();
            while (rs.next()) {
                StudentCourse student = new StudentCourse();
                student.setId(rs.getInt(1));
                student.setStudentName(rs.getString(2));
                student.setCourseName(rs.getString(3));
                student.setCourseGrade(rs.getInt(4));
                student.setStudentID(rs.getString(5));
                list.add(student);
            }
        } catch (SQLException e1) {
            e1.printStackTrace();
        } finally {
            try {
                DbConnection.colse(rs, stmt, conn);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
        Object[][] objects = new Object[list.size()][5];
        for (int i = 0; i < list.size(); i++) {
            objects[i][0] = list.get(i).getId();
            objects[i][1] = list.get(i).getStudentName();
            objects[i][2] = list.get(i).getCourseName();
            objects[i][3] = list.get(i).getCourseGrade();
            objects[i][4] = list.get(i).getStudentID();
        }
        return objects;
    }
    //导出成绩
    public void inputInfo() throws IOException {
        FileWriter fileWriter = new FileWriter(new File("info.txt"));
        String sql = " SELECt course_name,max(course_grade),min(course_grade),avg(course_grade)n" +
                "FROM test.studentcoursen" +
                "group by course_name;n" +
                ";";
        System.out.println(sql);
        Connection conn = DbConnection.getConnection();
        PreparedStatement stmt = null;
        ResultSet rs = null;
        ArrayList list = new ArrayList<>();
        try {
            stmt = (PreparedStatement) conn.prepareStatement(sql);
            rs = stmt.executeQuery();
            while (rs.next()) {
                inputStudentInfo info = new inputStudentInfo();
                info.setName(rs.getString(1));
                info.setMax(rs.getInt(2));
                info.setMin(rs.getInt(3));
                info.setAvg(rs.getDouble(4));
                list.add(info);
            }
        } catch (SQLException e1) {
            e1.printStackTrace();
        } finally {
            try {
                DbConnection.colse(rs, stmt, conn);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
        list.forEach(
               x->{
                   try {
                       fileWriter.write("课程名称:"+x.getName()+"课程最高分"+x.getMax()+"课程最低分:"+x.getMin()+"课程平均分"+x.getAvg()+"n");
                   } catch (IOException e) {
                       throw new RuntimeException(e);
                   }
               }
        );
        fileWriter.close();
    }

}

update类的编写

package Controller;


import Utils.DbConnection;

import javax.swing.*;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;


public class Updata {
    // 添加数据
    public int addData(String sql) {
        Connection conn = DbConnection.getConnection();
        // 获取连接
        PreparedStatement stmt = null;
        ResultSet rs = null;
        try {
            System.out.println(sql);
            stmt = conn.prepareStatement(sql);
            int executeUpdate = stmt.executeUpdate();
            return executeUpdate;
        } catch (SQLException e) {
            JOptionPane.showMessageDialog(null, "执行语句出错n" + e.toString());
            e.printStackTrace();
        }finally {
            try {
                DbConnection.colse(rs, stmt, conn);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
        return 0;
    }

}

对应的数据库表的实体类

管理员类的编写

package POJO;

//管理类
public class Admin {
    //数据库对应ID，方便操作
    private Integer ID;
    //用户名
    private String username;
    //密码
    private String password;


    public Admin(Integer ID, String username, String password, String nickName) {
        this.ID = ID;
        this.username = username;
        this.password = password;
    }

    public Integer getID() {
        return ID;
    }

    public void setID(Integer ID) {
        this.ID = ID;
    }

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

}

inputstudentinfo类的编写（接收和处理要导出的成绩信息）

package POJO;


public class inputStudentInfo {
    private String name;
    private Integer max;
    private Integer min;
    private Double avg;

    public inputStudentInfo(String name, Integer max, Integer min, Double avg) {
        this.name = name;
        this.max = max;
        this.min = min;
        this.avg = avg;
    }

    public inputStudentInfo() {
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Integer getMax() {
        return max;
    }

    public void setMax(Integer max) {
        this.max = max;
    }

    public Integer getMin() {
        return min;
    }

    public void setMin(Integer min) {
        this.min = min;
    }

    public Double getAvg() {
        return avg;
    }

    public void setAvg(Double avg) {
        this.avg = avg;
    }
}

student类的编写

package POJO;


    public class Student {
        //学生学号，数据库自增
        private Integer ID;
        //姓名
        private String name;
        //性别
        private String sex;
        //出生年月日
        private String dateOfBirth;

    //学号
    private String studentID;

    public Student() {
    }

    public Student(Integer ID, String name, String sex, String dateOfBirth, String studentID) {
        this.ID = ID;
        this.name = name;
        this.sex = sex;
        this.dateOfBirth = dateOfBirth;
        this.studentID = studentID;
    }

    public Integer getID() {
        return ID;
    }

    public void setID(Integer ID) {
        this.ID = ID;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getSex() {
        return sex;
    }

    public void setSex(String sex) {
        this.sex = sex;
    }

    public String getDateOfBirth() {
        return dateOfBirth;
    }

    public void setDateOfBirth(String dateOfBirth) {
        this.dateOfBirth = dateOfBirth;
    }

    public String getStudentID() {
        return studentID;
    }

    public void setStudentID(String studentID) {
        this.studentID = studentID;
    }
}

studentcourse类的编写

package POJO;

//学生的课程成绩
public class StudentCourse {
    //编号
    private Integer id;
    //学生名称
    private String studentName;
    //课程名称
    private String courseName;
    //课程成绩
    private Integer courseGrade;

    //学号
    private String studentID;

    public StudentCourse() {
    }

    public StudentCourse(Integer id, String studentName, String courseName, Integer courseGrade, String studentID) {
        this.id = id;
        this.studentName = studentName;
        this.courseName = courseName;
        this.courseGrade = courseGrade;
        this.studentID = studentID;
    }

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getStudentName() {
        return studentName;
    }

    public void setStudentName(String studentName) {
        this.studentName = studentName;
    }

    public String getCourseName() {
        return courseName;
    }

    public void setCourseName(String courseName) {
        this.courseName = courseName;
    }

    public Integer getCourseGrade() {
        return courseGrade;
    }

    public void setCourseGrade(Integer courseGrade) {
        this.courseGrade = courseGrade;
    }

    public String getStudentID() {
        return studentID;
    }

    public void setStudentID(String studentID) {
        this.studentID = studentID;
    }
}

AdminView类的编写，负责管理员的选择登陆界面

package View;

import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;


public class AdminView extends JFrame {

    public static StudentCourseView studentCourseView = new StudentCourseView();

    public static StudentView studentView = new StudentView();
    public AdminView(){
        super("学生管理系统");
        getContentPane().setFont(new Font("宋体", Font.PLAIN, 35));
        this.setBounds(0, 0, 900, 400);
        this.setLocationRelativeTo(null);// 让窗口在屏幕中间显示
        this.setResizable(false);
        getContentPane().setLayout(null);
        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);// 用户单击窗口的关闭按钮时程序执行的操作

        JLabel lblxxx = new JLabel("你好,欢迎使用学生管理系统");
        lblxxx.setFont(new Font("宋体", Font.PLAIN, 35));
        lblxxx.setBounds(44, 35, 726, 91);
        getContentPane().add(lblxxx);

        JButton button = new JButton("学生信息管理");
        button.setFont(new Font("宋体", Font.BOLD, 20));
        button.setBounds(10, 192, 300, 100);
        button.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent arg0) {
                studentView.setVisible(true);
                dispose();
            }
        });
        getContentPane().add(button);

        JButton button_1 = new JButton("学生成绩管理");
        button_1.setFont(new Font("宋体", Font.BOLD, 20));
        button_1.setBounds(500, 192, 300, 100);
        button_1.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent arg0) {
                studentCourseView.setVisible(true);
                dispose();
            }
        });
        getContentPane().add(button_1);
    }
}

StudentCourseView类的编写

package View;

import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;


public class AdminView extends JFrame {

    public static StudentCourseView studentCourseView = new StudentCourseView();

    public static StudentView studentView = new StudentView();
    public AdminView(){
        super("学生管理系统");
        getContentPane().setFont(new Font("宋体", Font.PLAIN, 35));
        this.setBounds(0, 0, 900, 400);
        this.setLocationRelativeTo(null);// 让窗口在屏幕中间显示
        this.setResizable(false);
        getContentPane().setLayout(null);
        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);// 用户单击窗口的关闭按钮时程序执行的操作

        JLabel lblxxx = new JLabel("你好,欢迎使用学生管理系统");
        lblxxx.setFont(new Font("宋体", Font.PLAIN, 35));
        lblxxx.setBounds(44, 35, 726, 91);
        getContentPane().add(lblxxx);

        JButton button = new JButton("学生信息管理");
        button.setFont(new Font("宋体", Font.BOLD, 20));
        button.setBounds(10, 192, 300, 100);
        button.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent arg0) {
                studentView.setVisible(true);
                dispose();
            }
        });
        getContentPane().add(button);

        JButton button_1 = new JButton("学生成绩管理");
        button_1.setFont(new Font("宋体", Font.BOLD, 20));
        button_1.setBounds(500, 192, 300, 100);
        button_1.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent arg0) {
                studentCourseView.setVisible(true);
                dispose();
            }
        });
        getContentPane().add(button_1);
    }
}

StudentView类的编写
下面展示一些 内联代码片。

package View;

import Controller.Select;
import Controller.Updata;

import javax.swing.*;
import javax.swing.border.TitledBorder;
import javax.swing.table.DefaultTableModel;
import java.awt.event.*;
import java.io.IOException;
import java.util.Objects;


public class StudentView extends JFrame {
    Select select = new Select();
    Updata updata = new Updata();
    private JTable table;
    DefaultTableModel df;

    Object[][] data = null;
    String[] header =  new String[] { "数据编号","学生姓名" ,"性别","出生年月日","学号" };
    private JTextField searchid;
    
    private JTextField ID;

    private JTextField name;

    private JTextField sex;

    private JTextField dateOfBirth;

    private JTextField studentID;
    public StudentView(){

        super("学生信息管理");
        data = select.selectStudentAll();
        this.setBounds(0, 0, 935, 700);
        this.setLocationRelativeTo(null);// 让窗口在屏幕中间显示
        this.setResizable(false);
        getContentPane().setLayout(null);

        JScrollPane scrollPane = new JScrollPane();
        scrollPane.setBounds(27, 321, 876, 331);
        getContentPane().add(scrollPane);
        //数据版
        table = new JTable();
        df = new DefaultTableModel(data,header);
        table.setModel(df);
        scrollPane.setViewportView(table);
        table.addMouseListener(new MouseListener() {

            @Override
            public void mouseReleased(MouseEvent e) {
                // 处理鼠标释放
            }

            @Override
            public void mousePressed(MouseEvent e) {
                // 处理鼠标按下
            }

            @Override
            public void mouseExited(MouseEvent e) {
                // 处理鼠标离开
            }

            @Override
            public void mouseEntered(MouseEvent e) {
                // 处理鼠标移入
            }

            public void mouseClicked(MouseEvent e) {
                // 处理鼠标点击
                ID.setText(table.getValueAt(table.getSelectedRow(),0).toString());
                name.setText(table.getValueAt(table.getSelectedRow(),1).toString());
                sex.setText(table.getValueAt(table.getSelectedRow(),2).toString());
                dateOfBirth.setText(table.getValueAt(table.getSelectedRow(),3).toString());
                studentID.setText(table.getValueAt(table.getSelectedRow(),4).toString());
            }
        });

        JPanel panel = new JPanel();
        panel.setBorder(new TitledBorder(null, "学生信息", TitledBorder.LEADING, TitledBorder.TOP, null, null));
        panel.setBounds(27, 27, 876, 200);
        getContentPane().add(panel);
        panel.setLayout(null);

        JLabel label = new JLabel("数据编号:");
        label.setBounds(32, 30, 75, 18);
        panel.add(label);

        ID = new JTextField();
        ID.setBounds(112, 26, 171, 24);
        panel.add(ID);
        ID.setEditable(false);
        ID.setColumns(10);

        JLabel label_1 = new JLabel("学生姓名：");
        label_1.setBounds(300, 30, 75, 18);
        panel.add(label_1);

        name = new JTextField();
        name.setBounds(400, 26, 171, 24);
        panel.add(name);
        name.setColumns(10);

        JLabel label_1_1 = new JLabel("学生性别:");
        label_1_1.setBounds(32, 60, 60, 18);
        panel.add(label_1_1);

        sex = new JTextField();
        sex.setColumns(10);
        sex.setBounds(112, 60, 171,24);
        panel.add(sex);

        JLabel label_1_1_1 = new JLabel("出生年月:");
        label_1_1_1.setBounds(300, 60, 75, 18);
        panel.add(label_1_1_1);

        dateOfBirth = new JTextField();
        dateOfBirth.setBounds(400, 60, 171, 24);
        panel.add(dateOfBirth);
        dateOfBirth.setColumns(10);

        JLabel label_1_1_1_1 = new JLabel("学生学号:");
        label_1_1_1_1.setBounds(32, 90, 60, 18);
        panel.add(label_1_1_1_1);

        studentID = new JTextField();
        studentID.setColumns(10);
        studentID.setBounds(112, 90, 171,24);
        panel.add(studentID);

        JPanel panel_1 = new JPanel();
        panel_1.setBorder(new TitledBorder(null, "条件查询", TitledBorder.LEADING, TitledBorder.TOP, null, null));

        panel_1.setBounds(27, 240, 531, 68);
        getContentPane().add(panel_1);

        JLabel label_5 = new JLabel("学生姓名:");
        panel_1.add(label_5);

        searchid = new JTextField();
        panel_1.add(searchid);
        searchid.setColumns(10);

        JButton searchBuut = new JButton("查询");
        panel_1.add(searchBuut);
        searchBuut.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                // 处理鼠标点击
                name.setText("");
                ID.setText("");
                dateOfBirth.setText("");
                sex.setText("");
                studentID.setText("");
                String name = searchid.getText();
                Object[][] data = select.selectStudentByName(name);
                df.setDataVector(data, header);
            }
        });

        JButton upBuut = new JButton("重置");
        panel_1.add(upBuut);
        upBuut.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                // 处理鼠标点击
                name.setText("");
                ID.setText("");
                sex.setText("");
                dateOfBirth.setText("");
                searchid.setText("");
                studentID.setText("");
                Object[][] data = select.selectStudentAll();
                df.setDataVector(data, header);
            }
        });
        searchBuut.setIcon(new ImageIcon(Objects.requireNonNull(StudentView.class.getResource(""))));

        JButton addButt = new JButton("添加");
        addButt.setBounds(700, 265, 80, 27);
        getContentPane().add(addButt);

        addButt.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                String sName = name.getText();
                String sSex = sex.getText();
                String sDateOfBirth = dateOfBirth.getText();
                String sstringID = studentID.getText();
                String sql = "INSERT INTO  student VALUES(null,'" + sName + "','"+sSex+"','" + sDateOfBirth+ "','" + sstringID+ "')";
                int reselt = updata.addData(sql);
                if (reselt > 0) {
                    JOptionPane.showMessageDialog(null, "添加学生信息成功！");
                } else {
                    JOptionPane.showMessageDialog(null, "添加失败！");
                }
                refresh();
            }
        });

        JButton updataButt = new JButton("修改");
        updataButt.setBounds(559, 265, 100, 27);
        getContentPane().add(updataButt);

        updataButt.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                String sName = name.getText();
                String sSex = sex.getText();
                String sDateOfBirth = dateOfBirth.getText();
                String id = ID.getText();
                String sstringID= studentID.getText();
                if (sName.equals("") && sSex.equals("") && sDateOfBirth.equals("")) {
                    JOptionPane.showMessageDialog(null, "请填写完整信息！");
                } else {
                    String sql = "UPDATE student SET `name`='"+sName+"',sex='"+sSex+"',`dateOfBirth`='"+sDateOfBirth+"',`school_id`='"+sstringID+"' WHERe id='"+id+"'";
                    int reselt = updata.addData(sql);
                    if (reselt > 0) {
                        JOptionPane.showMessageDialog(null, "修改信息成功！");
                    } else {
                        JOptionPane.showMessageDialog(null, "添加失败！");
                    }
                }
                refresh();
            }
        });

        JButton button_3 = new JButton("删除");
        button_3.setBounds(800, 265, 100, 27);
        getContentPane().add(button_3);
        button_3.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                if (table.getSelectedColumn() < 0) {
                    JOptionPane.showMessageDialog(null, "请选中要删除的数据！");
                } else {
                    String text = ID.getText();
                    String dsql = "delete from student where id=" + text;
                    int result = updata.addData(dsql);
                    if (result > 0) {
                        JOptionPane.showMessageDialog(null, "删除成功！");
                        Object[][] data = select.selectStudentAll();
                        df.setDataVector(data, header);
                    } else {
                        JOptionPane.showMessageDialog(null, "删除失败！");
                    }
                }
            }
        });

        this.addWindowListener(new WindowAdapter() {
            public void windowClosing(WindowEvent e) {
                super.windowClosing(e);
                new AdminView().setVisible(true);
            }
        });

    }

    public void refresh(){
        name.setText("");
        ID.setText("");
        sex.setText("");
        dateOfBirth.setText("");
        searchid.setText("");
        studentID.setText("");
        Object[][] data = select.selectStudentAll();
        df.setDataVector(data, header);
    }
}

UserLogin类的编写
下面展示一些 内联代码片。

package View;

import Controller.Select;

import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;


public class UserLogin extends JFrame{
    String uid;
    private static JTextField username;
    private JTextField password;
    JCheckBox chckbxNewCheckBox;

    public UserLogin() {
        super("学生管理系统后台登陆");
        Select select = new Select();
        this.setBounds(0, 0, 600, 350);
        this.setLocationRelativeTo(null);// 让窗口在屏幕中间显示
        this.setResizable(false);// 让窗口大小不可改变
        getContentPane().setLayout(null);
        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);// 用户单击窗口的关闭按钮时程序执行的操作
        this.setIconImage(Toolkit.getDefaultToolkit().getImage(UserLogin.class.getResource("")));

        JLabel usernameText = new JLabel("账号：");
        usernameText.setBounds(142, 70, 72, 18);
        usernameText.setIcon(new ImageIcon(UserLogin.class.getResource("")));
        getContentPane().add(usernameText);

        username = new JTextField();
        username.setBounds(228, 67, 203, 24);
        getContentPane().add(username);
        username.setColumns(10);

        JLabel passwordText = new JLabel("密码：");
        passwordText.setIcon(new ImageIcon(UserLogin.class.getResource("")));
        passwordText.setBounds(142, 138, 72, 18);

        getContentPane().add(passwordText);

        password = new JPasswordField();
        password.setColumns(10);
        password.setBounds(228, 135, 203, 24);
        getContentPane().add(password);

        JButton logButton = new JButton("登录");
        logButton.setIcon(new ImageIcon(UserLogin.class.getResource("")));
        logButton.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                String uname = username.getText();
                String pwd = password.getText();
                if (uname.equals("") && pwd.equals("")) {
                    JOptionPane.showMessageDialog(null, "账户名或密码未填写！");
                } else {
                    //核心判断语句
                    String sql = "select COUNT(*) from admin where username='" + uname + "' and password='" + pwd
                            + "'";
                    int reselt = select.userloginSelect(sql);
                    if (reselt > 0) {
                        JOptionPane.showMessageDialog(null, "登录成功！欢迎使用！");
                        new AdminView().setVisible(true);
                        dispose();
                    } else {
                        JOptionPane.showMessageDialog(null, "登录失败！账户名或密码不正确！请重新输入！");
                    }
                }
            }
        });
        logButton.setBounds(318, 228, 113, 27);
        getContentPane().add(logButton);

        JButton regButton = new JButton("重置");
        regButton.setIcon(new ImageIcon(UserLogin.class.getResource("")));
        regButton.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                username.setText("");
                password.setText("");
            }
        });
        regButton.setBounds(142, 228, 113, 27);
        getContentPane().add(regButton);
    }

//	public static String getUsername() {
//		if (username.getText().equals("")) {
//			return username.getText();
//		}
//		return "系统管理员";
//	}

    public static void main(String[] args) {
        new UserLogin().setVisible(true);
    }

}

utils包下的DbConnection类代码如下

package Utils;

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


public class DbConnection {
    // 驱动类的类名
    private static final String DRIVERNAME = "com.mysql.cj.jdbc.Driver";
    // 连接数据的URL路径
    private static final String URL = "jdbc:mysql://127.0.0.1:3306/test?useUnicode=true&characterEncoding=UTF-8&useSSL=false";
    // 数据库登录账号
    private static final String USER = "root";
    // 数据库登录密码
    private static final String PASSWORD = "yuyue123";
    // 加载驱动
    static {
        try {
            Class.forName(DRIVERNAME);
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }
    }

    // 获取数据库连接
    public static Connection getConnection() {
        try {
            return DriverManager.getConnection(URL, USER, PASSWORD);
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return null;
    }

    // 查询
    public static ResultSet query(String sql) {
        System.out.println(sql);
        // 获取连接
        Connection connection = getConnection();
        PreparedStatement psd;
        try {
            psd = connection.prepareStatement(sql);
            return psd.executeQuery();
        } catch (SQLException e) {
            JOptionPane.showMessageDialog(null, "执行语句出错n" + e.toString());
            e.printStackTrace();
        }
        return null;
    }

    // 增、删、改、查
    public static int updataInfo(String sql) {
        System.out.println(sql);
        // 获取连接
        Connection connection = getConnection();
        try {
            PreparedStatement psd = connection.prepareStatement(sql);
            return psd.executeUpdate();
        } catch (SQLException e) {
            JOptionPane.showMessageDialog(null, "执行语句出错n" + e.toString());
            e.printStackTrace();
        }
        return 0;
    }

    // 关闭连接
    public static void colse(ResultSet rs, PreparedStatement stmt, Connection conn) throws Exception {
        try {
            if (rs != null) {
                rs.close();
            }
            if (stmt != null) {
                stmt.cancel();
            }
            if (conn != null) {
                conn.close();
            }
        } catch (Exception e) {
            e.printStackTrace();
            throw new Exception();
        }
    }

    public static void main(String[] args) {

    }
}

package Main;

import View.UserLogin;


public class DoMain {
    public static void main(String[] args) {
        new UserLogin().setVisible(true);
    }
}

写的比较草率，等课设答辩完会仔细修稿。