（windows综合程序）设计一个学生平时成绩统计软件 最后的Java作业

1、（windows综合程序）设计一个学生平时成绩统计软件。要求：

(1) 录入课程名称(进入系统时录入)、学生姓名、学号、成绩、日期(自动生成日期并在界面显示)，除第一次外其他次数输入只需要录入学号、成绩，其他自动产生，录入要求所有项目不能为空，界面设计自己定义，每录入一笔记录暂时放在内存，当点击按钮保存时再写入数据库。每次只能录入一次的学生平时成绩（同一日期，所有学生的成绩）

(2) 数据库端建立数据库表(第一次录入课程名称时创建以课程名为名字的表)，含字段：学号、姓名、第一次平时成绩、第二次次平时成绩(共10次成绩)、平时平均成绩(自动计算)

(3) 查询和浏览学生平时成绩，要求：

① 查询平时成绩时只要录入学号则显示窗体显示：姓名、学号、目前为止平均平时成绩。

② 浏览学生成绩时呀求逐笔学生记录显示学生成绩，每次按按纽‘下一笔’时显示下一位学生的成绩

(4) 生成学生平时成绩EXECL表，将数据库中的学生成绩生成一个表格放在本地(这项不要求每位同学做，愿意做的可以查找相关资料后做)

其他在上面没有提出的自己确定，包括界面形式等，只要能够让系统达到上述要求即可。

以下是我的源代码：

package endtest;


import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.Statement;
import java.sql.*;
import java.text.SimpleDateFormat;
import java.time.LocalDate;
import java.util.Calendar;
import java.util.Date;
import java.util.Scanner;


public class myjdbc {
    private static final String url = "jdbc:mysql://localhost:3306/student?useSSL=false&serverTimezone=UTC";
    private static final String name = "com.mysql.cj.jdbc.Driver";
    private static final String user = "root";
    private static final String password = "06101010lu";
    private Connection conn = null;
    private Statement pst = null;

    public void getDataBaseConnection(){
        try{
            Class.forName(name);
            conn = DriverManager.getConnection(url, user, password);
            System.out.println("已成功的与数据库MySQL建立连接！！");
        }catch(Exception e){
            System.out.println("连接失败！！");
            e.printStackTrace();
        }
    }
    public void init(){
        try {
            pst = conn.createStatement();
            String sql = "CREATE TABLE IF NOT EXISTS register(USER VARCHAR(200),PWD VARCHAR(200))";
            pst.executeUpdate(sql);
        }catch (SQLException e) {
            e.printStackTrace();
        }
    }
    public void addUser(String user,String pwd){
        System.out.println(user+"  yy  "+pwd);
        try {
            pst = conn.createStatement();
            String sql = "INSERT INTO register(USER,PWD) values('"+user+"','"+pwd+"')";
            pst.executeUpdate(sql);
            System.out.println("yes");
        }catch (SQLException e) {
            System.out.println("fails!");
            e.printStackTrace();
        }
    }
    public boolean checkUser(String user,String pwd){
        try {
            pst = conn.createStatement();
            String sql = "SELECT * FROM register WHERE USER = "+user+" AND PWD = "+pwd;
            ResultSet ans = pst.executeQuery(sql);
            if(ans.next()) return true;
            return false;
        }catch (SQLException e) {
            e.printStackTrace();
        }
        return false;
    }

    public void close() {
        try {
            this.conn.close();
            this.pst.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

    public void creatMyTable(String tableName) {
        try{
            System.out.println("请输入课程名称："+tableName+" ");
            pst = conn.createStatement();
            String sql = "CREATE TABLE IF NOT EXISTS "
                    + tableName
                    +"(ID VARCHAR(200),CNAME VARCHAR(200),SCORE FLOAT,CSUM FLOAT ,NUM FLOAT ,CTIME char(200))";
            pst.executeUpdate(sql);
            System.out.println("成功创建学生表！！！");
        }catch(SQLException e){
            e.printStackTrace();
        }
    }

    public boolean checkTable(String tableName){
        try {
            System.out.println("fd:"+tableName);
            ResultSet ans  = conn.getMetaData().getTables(null, null, tableName, null );
            if(ans.next()) return true;
            return false;
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return false;
    }

    public void saveMyTable(String tableName,String name,String id,float score) {
        try {
            LocalDate date = LocalDate.now(); // get the current date
            String time = date.toString();
            System.out.println(date+"  "+time);
            pst = conn.createStatement();
            String sql1 = "SELECT * FROM " + tableName + " WHERE ID="+id;
            ResultSet ans = pst.executeQuery(sql1);
            float sum = score,num = 1.0f;
            if(ans.next()){
                sum +=ans.getFloat("CSUM");
                num +=ans.getFloat("NUM");
                score = sum / num;
            }
            sql1 = "DELETE  FROM "+ tableName + " WHERE ID="+id;
            pst.executeUpdate(sql1);
            System.out.println(score + "  "+ sum+"  "+"  "+num);

            String sql ="INSERT INTO "
                    +tableName
                    +"(ID,CNAME,SCORE,CSUM,NUM,CTIME) VALUES('"+id+"','"+name+"',"+score+","+sum+","+num+",'"+time+"')";
            pst.executeUpdate(sql);// 返回影响的记录行数
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

    public void QueryStudent(String sc,String idn,String[] ans) {
        try{
            System.out.println(sc+"    ---   "+idn+"   ---   ");
            pst = conn.createStatement();
            String sql = "SELECT * FROM "+sc+" WHERE ID= "+idn;
            ResultSet rc = pst.executeQuery(sql);
            System.out.println("true!!!");
            // 展开结果集数据库
            if(rc.next()){
                // 通过字段检索
                ans[0]  = rc.getString("ID");
                ans[1] = rc.getString("CNAME");
                float score = rc.getInt("SCORE");
                ans[2] = Float.toString(score);
            }
        }catch(SQLException e) {
            e.printStackTrace();
        }
    }

    public String[][] DisplayStudent(String sc) {
        try{
            int now=0;
            String [][] res = new String[10000][3];
            pst =  conn.createStatement();
            String sql = "SELECT * FROM "+ sc;
            ResultSet rc = pst.executeQuery(sql);
            // 展开结果集数据库
            System.out.println("所有学生集合：");
            while(rc.next()){
                // 通过字段检索
                res[now][0] = rc.getString("ID");
                res[now][1] = rc.getString("CNAME");
                float score = rc.getInt("SCORE");
                res[now][2] = Float.toString(score);

                now++;
             }
            String [][] ans;
            if(now==0){
                ans = new String[1][3];
                ans[0][0]=ans[0][1]=ans[0][2]="此为空表！";
            }
            else{
                ans = new String[now][3];
                for(int i=0;i<now;i++){
                    ans[i]=res[i];
                }
            }
            return ans;
        }catch(SQLException e) {
            e.printStackTrace();
        }
        return new String[0][0];
    }

}

package endtest;
import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.geom.AffineTransform;

public class test {
    public static void main(String[] args){
        myjdbc jdbc = new myjdbc();
        jdbc.getDataBaseConnection();
        jdbc.init();

        JFrame frame = new JFrame("学生平时成绩统计系统");
        frame.setVisible(true);
        frame.setBounds(300,200,600,400);

        JPanel panel = new JPanel();
        frame.add(panel);
        //采用自定义设置，只有这样，JLabel才可以自定义在JPanel中的位置，不然JLevel是居中显示
        panel.setLayout(null);
        Font font = new Font("微软雅黑", Font.BOLD,18);

        JLabel user_lab = new JLabel("用户名：");
        user_lab.setFont(font);
        user_lab.setBounds(110,20,100,100);
        panel.add(user_lab);

        //创建输入的文本框
        JTextField user_Field = new JTextField();
        user_Field.setBounds(200,60,160,30);
        panel.add(user_Field);
        user_lab.setBackground(Color.white);

        //创建输入的密码框
        JLabel pwd = new JLabel("密码：");
        pwd.setFont(font);
        pwd.setBounds(110,100,160,30);
        panel.add(pwd);

        JPasswordField pwd_Field = new JPasswordField();
        pwd_Field.setBounds(200,100,160,30);
        pwd.setBackground(Color.white);
        panel.add(pwd_Field);

        JButton login = new JButton("登录");
        login.setBounds(180,150,80,30);
        panel.add(login);

        JButton register = new JButton("注册");
        register.setBounds(278,150,80,30);
        panel.add(register);
        register.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                //获取文本值的api
                JPanel RegisterPanel = new JPanel();
                RegisterPanel.setLayout(null);

                JLabel user = new JLabel("用户名：");
                user.setFont(font);
                user.setBounds(110,20,100,100);
                RegisterPanel.add(user);

                //创建输入的文本框
                JTextField user_F = new JTextField();
                user_F.setBounds(200,60,160,30);
                RegisterPanel.add(user_F);
                user.setBackground(Color.white);

                //创建第一个输入的密码框
                JLabel FirPwd = new JLabel("密码：");
                FirPwd.setFont(font);
                FirPwd.setBounds(110,100,160,30);
                RegisterPanel.add(FirPwd);

                JPasswordField FirPwdField = new JPasswordField();
                FirPwdField.setBounds(200,100,160,30);
                FirPwd.setBackground(Color.white);
                RegisterPanel.add(FirPwdField);

                //创建第二个输入的密码框
                JLabel SecPwd = new JLabel("确认密码：");
                SecPwd.setFont(font);
                SecPwd.setBounds(110,140,160,30);
                RegisterPanel.add(SecPwd);

                JPasswordField SecPwdField = new JPasswordField();
                SecPwdField.setBounds(200,140,160,30);
                SecPwd.setBackground(Color.white);
                RegisterPanel.add(SecPwdField);

                JButton reg = new JButton("注册");
                reg.setBounds(278,190,80,30);
                RegisterPanel.add(reg);

                JButton back = new JButton("返回");
                back.setBounds(180,190,80,30);
                RegisterPanel.add(back);

                panel.setVisible(false);
                frame.add(RegisterPanel);

                back.addActionListener(new ActionListener() {
                    @Override
                    public void actionPerformed(ActionEvent actionEvent) {
                        panel.setVisible(true);
                        RegisterPanel.setVisible(false);
                    }
                });
                reg.addActionListener(new ActionListener() {
                    @Override
                    public void actionPerformed(ActionEvent actionEvent) {
                        String user = user_F.getText().trim();
                        String pwd1 = FirPwdField.getText().trim();
                        String pwd2 = SecPwdField.getText().trim();
                        if(pwd1.equals(pwd2)&&!user.equals("")&&!pwd1.equals("")){
                            jdbc.addUser(user,pwd1);
                            frame.setVisible(false);
                            choose(jdbc);
                        }
                        else{
                            System.out.println("ssss help");
                            JFrame error = new JFrame("输入错误！！！");
                            error.setBounds(200,200,400,100);
                            JPanel er = new JPanel();
                            er.setLayout(null);
                            JLabel tip = new JLabel("两次密码输入不同！或者用户名为null！");
                            tip.setBounds(10,0,350,30);
                            JButton reback = new JButton("返回");
                            reback.setBounds(170,30,60,20);
                            er.add(tip);
                            er.add(reback);
                            error.add(er);

                            error.setVisible(true);
                            reback.addActionListener(new ActionListener() {
                                @Override
                                public void actionPerformed(ActionEvent actionEvent) {
                                    error.setVisible(false);
                                    panel.setVisible(true);
                                }
                            });
                        }
                    }
                });

            }
        });

        login.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                //获取文本值的api
                String username = user_Field.getText().trim();
                String password = pwd_Field.getText().trim();
                if(!password.equals("")&&!username.equals("")&&jdbc.checkUser(username,password)){
                    frame.setVisible(false);
                    choose(jdbc);
                }
                else {
                    JFrame error = new JFrame("密码错误");
                    error.setBounds(200,200,400,100);
                    JPanel er = new JPanel();
                    er.setLayout(null);
                    JLabel tip = new JLabel("账号不存在或密码错误！");
                    tip.setBounds(10,0,350,30);
                    JButton reback = new JButton("返回");
                    reback.setBounds(170,30,60,20);
                    er.add(tip);
                    er.add(reback);
                    error.add(er);

                    error.setVisible(true);
                    reback.addActionListener(new ActionListener() {
                        @Override
                        public void actionPerformed(ActionEvent actionEvent) {
                            error.setVisible(false);
                        }
                    });
                }
            }
        });
    }


    public static void choose(myjdbc jdbc){
        JFrame frame = new JFrame("学生平时成绩统计系统");
        frame.setVisible(true);
        frame.setBounds(300,200,600,400);

        JPanel panel = new JPanel();
        frame.add(panel);
        //采用自定义设置，只有这样，JLabel才可以自定义在JPanel中的位置，不然JLevel是居中显示
        panel.setLayout(null);
        Font font = new Font("微软雅黑", Font.BOLD,14);

        JButton first = new JButton("建立表格");
        first.setBounds(200,20,150,50);
        first.setFont(font);
        panel.add(first);


        JButton other = new JButton("录入成绩");
        other.setBounds(200,100,150,50);
        other.setFont(font);
        panel.add(other);

        JButton query = new JButton("查询成绩");
        query.setBounds(200,180,150,50);
        query.setFont(font);
        panel.add(query);


        JButton watch = new JButton("浏览成绩");
        watch.setBounds(200,260,150,50);
        watch.setFont(font);
        panel.add(watch);

        first.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent actionEvent) {
                panel.setVisible(false);
                JPanel create = new JPanel();
                create.setLayout(null);
                frame.add(create);

                JLabel Input = new JLabel("表格的名字：");
                Input.setBounds(10,50,100,30);
                Input.setFont(font);
                create.add(Input);

                JTextField input = new JTextField();
                input.setBounds(120,50,200,30);
                input.setFont(font);
                create.add(input);

                JButton back = new JButton("返回");
                back.setFont(font);
                back.setBounds(100,100,100,30);
                create.add(back);

                JButton submit = new JButton("提交");
                submit.setFont(font);
                submit.setBounds(220,100,100,30);
                create.add(submit);

                back.addActionListener(new ActionListener() {
                    @Override
                    public void actionPerformed(ActionEvent actionEvent) {
                        create.setVisible(false);
                        panel.setVisible(true);
                    }
                });

                submit.addActionListener(new ActionListener() {
                    @Override
                    public void actionPerformed(ActionEvent actionEvent) {
                        String c = input.getText().trim();
                        boolean f = false;
                        if(c.length() == 0) ;
                        else if(c.charAt(0)<='z'&&c.charAt(0)>='a') f = true;
                        else if(c.charAt(0)<='Z'&&c.charAt(0)>='A') f = true;
                        else if(c.charAt(0)=='_') f = true;
                        if(f&&!jdbc.checkTable(c)) {
                            jdbc.creatMyTable(c);
                            create.setVisible(false);
                            panel.setVisible(true);
                        }
                        else{
                            JFrame error = new JFrame("表格错误");
                            error.setBounds(200,200,400,100);
                            JPanel er = new JPanel();
                            er.setLayout(null);
                            JLabel tip = new JLabel("表格名字不符合规范或表格已经存在！！");
                            tip.setBounds(10,0,350,30);
                            JButton reback = new JButton("返回");
                            reback.setBounds(170,30,60,20);
                            er.add(tip);
                            er.add(reback);
                            error.add(er);

                            error.setVisible(true);
                            reback.addActionListener(new ActionListener() {
                                @Override
                                public void actionPerformed(ActionEvent actionEvent) {
                                    error.setVisible(false);
                                }
                            });
                        }
                    }
                });
            }
        });

        other.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent actionEvent) {
                panel.setVisible(false);
                JPanel FPanel = new JPanel();
                FPanel.setLayout(null);
                frame.add(FPanel);
                JLabel Course = new JLabel("课程：");
                Course.setBounds(100,50,100,30);
                Course.setFont(font);
                FPanel.add(Course);
                JTextField course = new JTextField();
                course.setBounds(160,50,200,30);
                FPanel.add(course);

                JLabel Name = new JLabel("姓名：");
                Name.setBounds(100,100,100,30);
                Name.setFont(font);
                FPanel.add(Name);
                JTextField name = new JTextField();
                name.setBounds(160,100,200,30);
                FPanel.add(name);

                JLabel ID = new JLabel("学号：");
                ID.setBounds(100,150,100,30);
                ID.setFont(font);
                FPanel.add(ID);
                JTextField id = new JTextField();
                id.setBounds(160,150,200,30);
                id.setFont(font);
                FPanel.add(id);

                JLabel Score = new JLabel("成绩：");
                Score.setBounds(100,200,100,30);
                Score.setFont(font);
                FPanel.add(Score);
                JTextField score = new JTextField();
                score.setBounds(160,200,200,30);
                score.setFont(font);
                FPanel.add(score);

                JButton last = new JButton("取消");
                last.setBounds(150,250,100,30);
                last.setFont(font);
                FPanel.add(last);

                JButton com = new JButton("提交");
                com.setBounds(260,250,100,30);
                com.setFont(font);
                FPanel.add(com);

                last.addActionListener(new ActionListener() {
                    @Override
                    public void actionPerformed(ActionEvent actionEvent) {
                        FPanel.setVisible(false);
                        panel.setVisible(true);
                    }
                });


                com.addActionListener(new ActionListener() {
                    @Override
                    public void actionPerformed(ActionEvent actionEvent) {
                        String c = course.getText().trim();
                        String n = name.getText().trim();
                        String d = id.getText().trim();
                        String ss = score.getText().trim();
                        int s = 0;
                        for(int i=0;i<ss.length();i++){
                            s=s*10+ss.charAt(i)-'0';
                        }
                        boolean idNum = jdbc.checkTable(c);
                        System.out.println(idNum+"  really");
                        if(idNum&&s<=100&&s>=0&&n.length()!=0&&d.length()==9){
                            jdbc.saveMyTable(c,n,d,s);
                            panel.setVisible(true);
                            FPanel.setVisible(false);
                        }
                        else{
                            JFrame error = new JFrame("输入错误");
                            error.setBounds(200,200,400,230);
                            JPanel er = new JPanel();
                            er.setLayout(null);
                            error.add(er);

                            JLabel tip1 = new JLabel("tip1:课程号不能为空且首字母只能是字母或者下划线！");
                            tip1.setBounds(10,0,350,30);
                            er.add(tip1);

                            JLabel tip2 = new JLabel("tip2:名字不能为空！");
                            tip2.setBounds(10,50,350,30);
                            er.add(tip2);

                            JLabel tip3 = new JLabel("tip3:学号必须是9位并且表格必须存在数据库之中！");
                            tip3.setBounds(10,100,350,30);
                            er.add(tip3);

                            JButton reback = new JButton("返回");
                            reback.setBounds(170,150,60,20);
                            er.add(reback);

                            error.setVisible(true);
                            reback.addActionListener(new ActionListener() {
                                @Override
                                public void actionPerformed(ActionEvent actionEvent) {
                                    error.setVisible(false);
                                }
                            });
                        }
                    }
                });
            }
        });

        query.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent actionEvent) {
                JPanel which = new JPanel();
                frame.add(which);
                which.setLayout(null);
                which.setVisible(true);
                panel.setVisible(false);

                JLabel tip1 = new JLabel("请输入课程：");
                tip1.setFont(font);
                tip1.setBounds(100,100,100,30);
                which.add(tip1);

                JTextField answer1 = new JTextField();
                answer1.setFont(font);
                answer1.setBounds(200,100,300,30);
                which.add(answer1);

                JLabel tip2 = new JLabel("请输入学号：");
                tip2.setFont(font);
                tip2.setBounds(100,150,100,30);
                which.add(tip2);

                JTextField answer2 = new JTextField();
                answer2.setFont(font);
                answer2.setBounds(200,150,300,30);
                which.add(answer2);


                JButton reback = new JButton("返回");
                reback.setFont(font);
                reback.setBounds(270,200,100,20);
                which.add(reback);

                JButton submit = new JButton("提交");
                submit.setFont(font);
                submit.setBounds(400,200,100,20);
                which.add(submit);

                reback.addActionListener(new ActionListener() {
                    @Override
                    public void actionPerformed(ActionEvent actionEvent) {
                        which.setVisible(false);
                        panel.setVisible(true);
                    }
                });

                submit.addActionListener(new ActionListener() {
                    @Override
                    public void actionPerformed(ActionEvent actionEvent) {
                        String sc = answer1.getText().trim();
                        String idN = answer2.getText().trim();

                        String[] ans = new String[3];
                        ans[1]=ans[2]=ans[0]="查无此人！";
                        if(jdbc.checkTable(sc))jdbc.QueryStudent(sc,idN,ans);
                        else{
                            ans[0]=ans[1]=ans[2]="查无此表！";
                        }

                        JPanel show = new JPanel();
                        frame.add(show);
                        show.setLayout(null);
                        show.setVisible(true);
                        which.setVisible(false);
                        frame.add(show);


                        JLabel top = new JLabel("查询成绩");
                        top.setFont(font);
                        top.setBounds(250,20,100,30);
                        show.add(top);

                        JLabel name = new JLabel("姓名：");
                        name.setFont(font);
                        name.setBounds(100,60,100,30);
                        show.add(name);
                        JTextField Name = new JTextField(ans[0]);
                        Name.setFont(font);
                        Name.setBounds( 200,60,200,30);
                        show.add(Name);

                        JLabel id = new JLabel("学号：");
                        id.setFont(font);
                        id.setBounds(100,120,100,30);
                        show.add(id);
                        JTextField ID = new JTextField(ans[1]);
                        ID.setFont(font);
                        ID.setBounds(200,120,200,30);
                        show.add(ID);

                        JLabel score = new JLabel("成绩：");
                        score.setFont(font);
                        score.setBounds(100,180,100,30);
                        show.add(score);
                        JTextField Score = new JTextField(ans[2]);
                        Score.setFont(font);
                        Score.setBounds(200,180,200,30);
                        show.add(Score);


                        JButton back = new JButton("返回");
                        back.setBounds(300,240,100,30);
                        back.setFont(font);
                        show.add(back);

                        back.addActionListener(new ActionListener() {
                            @Override
                            public void actionPerformed(ActionEvent actionEvent) {
                                which.setVisible(true);
                                show.setVisible(false);
                            }
                        });
                    }
                });


            }
        });

        watch.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent actionEvent) {
                JPanel which = new JPanel();
                frame.add(which);
                which.setLayout(null);
                which.setVisible(true);
                panel.setVisible(false);

                JLabel tip1 = new JLabel("请输入课程：");
                tip1.setFont(font);
                tip1.setBounds(100,100,100,30);
                which.add(tip1);

                JTextField answer1 = new JTextField();
                answer1.setFont(font);
                answer1.setBounds(200,100,300,30);
                which.add(answer1);



                JButton reback = new JButton("返回");
                reback.setFont(font);
                reback.setBounds(270,150,100,20);
                which.add(reback);

                JButton submit = new JButton("提交");
                submit.setFont(font);
                submit.setBounds(400,150,100,20);
                which.add(submit);

                reback.addActionListener(new ActionListener() {
                    @Override
                    public void actionPerformed(ActionEvent actionEvent) {
                        which.setVisible(false);
                        panel.setVisible(true);
                    }
                });

                submit.addActionListener(new ActionListener() {
                    @Override
                    public void actionPerformed(ActionEvent actionEvent) {
                        String sc = answer1.getText().trim();
                        String[][] ans ;
                        if(!jdbc.checkTable(sc)){
                            ans = new String[1][3];
                            ans[0][0]=ans[0][1]=ans[0][2]="数据库中无此表！";
                        }
                        else{
                            ans = jdbc.DisplayStudent(sc);
                        }
                        int[] now = {0};

                        JPanel show = new JPanel();
                        frame.add(show);
                        show.setLayout(null);
                        show.setVisible(true);
                        which.setVisible(false);
                        frame.add(show);


                        JLabel top = new JLabel("查询成绩");
                        top.setFont(font);
                        top.setBounds(250,20,100,30);
                        show.add(top);

                        JLabel name = new JLabel("姓名：");
                        name.setFont(font);
                        name.setBounds(100,60,100,30);
                        show.add(name);
                        JTextField Name = new JTextField();
                        Name.setFont(font);
                        Name.setBounds( 200,60,200,30);
                        show.add(Name);
                        Name.setText(ans[now[0]][0]);

                        JLabel id = new JLabel("学号：");
                        id.setFont(font);
                        id.setBounds(100,120,100,30);
                        show.add(id);
                        JTextField ID = new JTextField();
                        ID.setFont(font);
                        ID.setBounds(200,120,200,30);
                        show.add(ID);
                        ID.setText(ans[now[0]][1]);

                        JLabel score = new JLabel("成绩：");
                        score.setFont(font);
                        score.setBounds(100,180,100,30);
                        show.add(score);
                        JTextField Score = new JTextField();
                        Score.setFont(font);
                        Score.setBounds(200,180,200,30);
                        show.add(Score);
                        Score.setText(ans[now[0]][2]);

                        JButton back = new JButton("下一页");
                        back.setBounds(300,240,100,30);
                        back.setFont(font);
                        show.add(back);



                        back.addActionListener(new ActionListener() {
                            @Override
                            public void actionPerformed(ActionEvent actionEvent) {
                                now[0]++;
                                if(now[0] < ans.length) {
                                    Name.setText(ans[now[0]][0]);
                                    ID.setText(ans[now[0]][1]);
                                    Score.setText(ans[now[0]][2]);
                                }
                                else{
                                    show.setVisible(false);
                                    which.setVisible(true);
                                }
                            }
                        });

                    }
                });

            }
        });

    }
}

其实我觉得做了很多重复的东西，还有很多值得改善的地方。

注意这个运行要导入mysql和Java的连接包。