Java学生管理系统（连接数据库查询）超详细

这几天逼着交Java，借鉴各位师傅的做出来这么个简陋的东西，各位大师傅不要笑我。（学都没有学过Java的我，QAQ~)

下面针对的都是SQL Server系列的连接，如果你使用MySQL那么不必看关于连接数据库的介绍。

数据库驱动JDBC在Ecilpse安装教程：点击进入

项目及素材下载链接：点击下载

常见问题：

端口拦截

连接数据库时，端口被防火墙拦截，检查端口是否开放，然后重启sql server服务。

代码使用

在使用代码时，需要额外创建一个包，如图创建

数据库账号密码问题

Java连接数据库需要SQL登录方式，需要账号密码，如果说不知道自己是否是混合登录，或者说忘记密码，可以这样做：

 打开数据库软件，连接数据库(Windows登录就可以了）。

右键你的本地数据库

 

打开属性，点击安全性，查看是否是SQL Server和Windows混合登录。（不是就点上）

接着依次打开安全性-->登录名，那个sa就是我的管理员账号。

双击点开，就可以在账号框和密码框进行账号名，密码更改，最后确认就行。

如果没有账号的话，右键登录名，选择新建登录名，重新创建一个SQL登陆方式的账户。

查看自己的数据库名称：

 

这个“master”就是我的数据库名称，同时也储存着我的数据。

代码：

Login.java

import java.awt.Color;
import java.awt.Cursor;
import java.awt.Font;
import java.awt.Image;
import java.awt.Point;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.BorderFactory;
import javax.swing.ButtonGroup;
import javax.swing.Icon;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JPasswordField;
import javax.swing.JRadioButton;
import javax.swing.JTextField;

import pack.VerCode;
public class Login {
    String StudentAccount="123456";  
    String StudentPassWord="123456";
    JLabel L, L1, L2, L3, L4, BK;
    JTextField te1, te3;
    JPasswordField te2;
    JRadioButton value1, value2;
    JButton B1, B2;
    ButtonGroup bg;
    JPanel jp1,jp2,jp3,jp4;
    //设置图标
    Icon v1 = new ImageIcon("p3.png");
    Icon v2 = new ImageIcon("p4.png");
    Icon v3 = new ImageIcon("p5.png");
    Icon v4 = new ImageIcon("p6.png");
    private VerCode VerCode = new VerCode();//引用验证码函数
    
    public static void main(String[] args) {
        Login frame=new Login();
        frame.show();
    }
        JFrame frame=new JFrame();//frame界面
    public void show() {    
        setBackgroudImage();
        
         Toolkit tk = Toolkit.getDefaultToolkit();//默认加载方式
         Image image = new ImageIcon(getClass().getResource("p6.png")).getImage();//设置光标图片
         Cursor cursor = tk.createCustomCursor(image, new Point(10, 10), "biubiubiu");//光标image属性，指定光标中心，光标文字描述
         frame.setCursor(cursor);
        
        L1=new JLabel("<html>账号:</html>");
        L1.setIcon(v1);
        te1=new JTextField(80);
        //设置密码窗口，使用'*'隐藏密码
        L2=new JLabel("<html>密码:</html>");
        L2.setIcon(v2);
        te2=new JPasswordField(80);//
        te2.setEchoChar('*');
        L4 = new JLabel("验证码:");
        L4.setIcon(v3);
        te3=new JTextField(80);
        
        //设置登录身份选择按钮
        jp2 = new JPanel();
        L3 = new JLabel("身份:");
        L3.setIcon(v4);
        value2=new JRadioButton("学生");
        SetBt(value2);
        
        //设置位置和大小
        L1.setBounds(60, 90, 60, 40);
        L2.setBounds(60, 140, 60, 40);
        L3.setBounds(60, 240, 60, 40);
        L4.setBounds(60, 190, 60, 40);
        
        jp2.setBounds(80, 240, 60, 40);
        te1.setBounds(130, 90, 150, 30);
        te2.setBounds(130, 140, 150, 30);
        te3.setBounds(130, 190, 150, 30);
        VerCode.setBounds(290, 190, 100, 40);
        value2.setBounds(120, 240, 60, 40);
        
        //设置'登录'及'重置'按钮
        B1=new JButton("登录");
        B1.setBounds(120, 280, 80, 40);
        SetBt(B1);
        ButtonListener li1=new ButtonListener(te1,te2);             
        
        B2=new JButton("注册");
        B2.setBounds(250, 280, 80, 40);
        SetBt(B2);
        ButtonListener li2=new ButtonListener(te1,te2);
        
        //设置监听  
        B1.addActionListener(li1);  
        B2.addActionListener(li2);  

        //组键添加到窗口
        frame.setLayout(null);
        //frame.add(L);
        
        frame.add(L1);
        frame.add(te1);
        
        frame.add(L2);
        frame.add(te2);
        
        frame.add(L3);
        frame.add(value2);
        
        frame.add(L4);
        frame.add(te3);
        frame.add(VerCode);
        
        frame.add(B1);
        frame.add(B2);
        frame.setVisible(true);//窗体设置为可见
        
        frame.setTitle("学生管理系统");
        frame.setSize(700,403);
        frame.setLocationRelativeTo(null);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setVisible(true);
        frame.setResizable(false);

    }

    private void SetBt(JButton b12) {
        b12.setBackground(new Color(102, 0, 204));//设置色值
        b12.setFont(new Font("宋体", Font.BOLD, 24));//设置字体，样式。字号
        b12.setOpaque(false);//设置控件透明
        b12.setBorder(BorderFactory.createEmptyBorder());
        
    }
    private void SetBt(JRadioButton b12) {
        b12.setBackground(new Color(102, 0, 204));
        b12.setFont(new Font("Dialog", Font.BOLD, 15));  
        b12.setOpaque(false);//设置控件透明
        b12.setBorder(BorderFactory.createEmptyBorder());
        
    }
    
    public boolean isValidCodeRight() {//判断验证码是否有效
        if(te3 == null) {
            return false;
        }else if(VerCode == null) {
            return true;
        }else if(VerCode.getCode() .equals(te3.getText())) {
            return true;
        }else 
            return false;
    }

    private void setBackgroudImage() {
        // TODO Auto-generated method stub
         ((JPanel) frame.getContentPane()).setOpaque(false);  
            ImageIcon img = new ImageIcon("3.gif"); // 添加图片  
            BK = new JLabel(img);  
            frame.getLayeredPane().add(BK, new Integer(Integer.MIN_VALUE));  
            BK.setBounds(0, 0, img.getIconWidth(), img.getIconHeight());  
    }

    //创建类实现接口
    public  class ButtonListener implements java.awt.event.ActionListener{    //实现ActionListener 接口 implement
        JTextField te1=new JTextField();               //传参
        JPasswordField te2=new JPasswordField();
        Function hua=new Function();                       //一个画板对象
        ButtonListener(JTextField te1,JPasswordField te2) {//重载 窗体上的账号框，密码框传到监听上来
            this.te1=te1;    
            this.te2=te2;
        }
        public ButtonListener(JTextField ID) {
            // TODO Auto-generated constructor stub
        }
        @Override
        public void actionPerformed(ActionEvent ch) {
            // TODO Auto-generated method stub
             if(ch.getActionCommand()=="登录")
                { 
                 if(te3.getText().isEmpty()) {
                        JOptionPane.showMessageDialog(null, "请输入验证码!");
                    }else {
                        if(!isValidCodeRight()) {
                            JOptionPane.showMessageDialog(null, "验证码错误,请重新输入!","错误",JOptionPane.ERROR_MESSAGE);
                            hua.bClear(te3);
                        }
                        else if(value2.isSelected()) 
                        {  
                        hua.Student(StudentAccount, StudentPassWord, te1, te2, frame, hua);//学生
                        }
                          
                        else if(ch.getActionCommand()=="重置")  
                        {  
                            hua.Clear(te1, te2);  
                        }
                    }
                      
                }
            
        }
        
    }
}

VerCode.java

package pack;
import java.awt.Color;  
import java.awt.Dimension;  
import java.awt.Font;  
import java.awt.FontMetrics;  
import java.awt.Graphics;  
import java.awt.Graphics2D;  
import java.awt.event.MouseEvent;  
import java.awt.event.MouseListener;  
 
import java.util.Random;  
  
import javax.swing.JComponent;  
  
public class VerCode extends JComponent implements MouseListener {  
  
    private String typeface;  
  
    private int V1, V2 = 30;  
  
    private int Len = 4;  
  
    private Random random = new Random();  
  
    public VerCode() {  
        V1 = this.Len * 16 + (this.Len - 1) * 10;  
        setPreferredSize(new Dimension(V1, V2));  
        setSize(V1, V2);  
        this.addMouseListener(this);  
        setToolTipText("点击可以更换验证码");  
    }  
  
    public int getCodeLength() {  
        return Len;  
    }  
  

    //设置验证码长度
    public void setCodeLength(int Len) {  
        if(Len < 4) {  
            this.Len = 4;  
        } else {  
            this.Len = Len;  
        }  
          
    }  
  
    public String getCode() {  
        return typeface;  
    }  
  
    //产生随机颜色
    public Color getRandColor(int min, int max) {  
  
        if (min > 255)  
            min = 255;  
        if (max > 255)  
            max = 255;  
        int red = random.nextInt(max - min) + min;  
        int green = random.nextInt(max - min) + min;  
        int blue = random.nextInt(max - min) + min;  
        return new Color(red, green, blue);  
    }  
    //设置验证码字母
    protected String generateCode() {  
        char[] codes = new char[this.Len];  
        for (int i = 0, len = codes.length; i < len; i++) {  
            if (random.nextBoolean()) {  
                codes[i] = (char) (random.nextInt(26) + 65);  
            } else {  
                codes[i] = (char) (random.nextInt(26) + 97);  
            }  
        }  
        this.typeface = new String(codes);  
        return this.typeface;  
    }  
  
    @Override  
    protected void paintComponent(Graphics g) {  
        super.paintComponent(g);  
        if(this.typeface == null || this.typeface.length() != this.Len) {  
            this.typeface = generateCode();  
        }  
        V1 = this.Len * 16 + (this.Len - 1) * 10;  
        super.setSize(V1, V2);  
        super.setPreferredSize(new Dimension(V1, V2));  
        Font mFont = new Font("Arial", Font.BOLD | Font.ITALIC, 25);  
        g.setFont(mFont);  
        //绘制验证码的背景的矩形轮廓  
        Graphics2D g2d = (Graphics2D) g;  
        g2d.setColor(getRandColor(200, 250));  
        g2d.fillRect(0, 0, V1, V2);  
        g2d.setColor(getRandColor(180, 200));  
        g2d.drawRect(0, 0, V1 - 1, V2 - 1);  
        //绘制验证码背景的线  
        int i = 0, len = 150;  
        for (; i < len; i++) {  
            int x = random.nextInt(V1 - 1);  
            int y = random.nextInt(V2 - 1);  
            int x1 = random.nextInt(V1 - 10) + 10;  
            int y1 = random.nextInt(V2 - 4) + 4;  
            g2d.setColor(getRandColor(180, 200));  
            g2d.drawLine(x, y, x1, y1);  
        }  
          
      
  
        //绘制出验证码的具体字母  
        i = 0; len = this.Len;  
        FontMetrics fm = g2d.getFontMetrics();  
        int base = (V2 - fm.getHeight())/2 + fm.getAscent();  
        for(;i<len;i++) {  
            int b = random.nextBoolean() ? 1 : -1;  
            g2d.rotate(random.nextInt(10)*0.01*b);  
            g2d.setColor(getRandColor(20, 130));  
            g2d.drawString(typeface.charAt(i)+"", 16 * i + 10, base);  
        }  
    }  
  
    //下一个验证码  
    public void nextCode() {  
        generateCode();  
        repaint();  
    }  
  
    @Override  
    public void mouseClicked(MouseEvent e) {  
          
        nextCode();  
    }  
  
    @Override  
    public void mousePressed(MouseEvent e) {  
        // TODO Auto-generated method stub  
          
    }  
  
    @Override  
    public void mouseReleased(MouseEvent e) {  
        // TODO Auto-generated method stub  
          
    }  
  
    @Override  
    public void mouseEntered(MouseEvent e) {  
        // TODO Auto-generated method stub  
          
    }  
  
    @Override  
    public void mouseExited(MouseEvent e) {  
        // TODO Auto-generated method stub  
          
    }  
}

Function.java

import java.awt.*;

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

import javax.swing.*;


public class Function extends JFrame implements ActionListener{
    String StuID, Stud_Name;
    String num;
    JTextField ID;
    JButton Select;
    JPanel Va, Vb;
    JTable ival;
    JScrollPane qval;
    DefaultTableModel rval;
    JLabel label;
    static Connection ct;  
    PreparedStatement ps;  
    ResultSet rs;
    
    //Connect connect = new Connect();
    //学生登录界面
    public void StudentShow() {
        Icon v1 = new ImageIcon("p3.png");
        Va=new JPanel();
        label=new JLabel();
        label.setIcon(v1);
        label.setText("学号");
        ID = new JTextField(15);
        
        Select=new JButton("查询");
        Select.addActionListener(this);
        //界面表格名添加
        String[] colnames = { "学号","姓名", "学院", "Java", "Python", "数据结构"};  
        rval = new DefaultTableModel(colnames, 3);  
        ival = new JTable(rval);  
        qval = new JScrollPane(ival);
        
        Va = new JPanel();
        Vb = new JPanel();
        
        Va.add(label);
        Va.add(ID);
        Va.add(Select);
        Vb.add(qval);
        //查询位置调整
        this.add(Va,BorderLayout.SOUTH);
        this.add(Vb);
        
        //界面属性设置
        this.setLocationRelativeTo(null); //居中
        this.setVisible(true);
        this.setSize(500,600);
        this.setDefaultCloseOperation(DISPOSE_ON_CLOSE);
        this.setTitle("学生管理系统");
        
    }

    //学生登录判断
     public void Student(String StudentAccount, String  StudentPassWord,JTextField te1, JPasswordField te2, JFrame frame, Function hua)  
        {
         if(StudentAccount.equals(te1.getText())&&StudentPassWord.equals(te2.getText()))  
            {  
                 JOptionPane.showMessageDialog(this, "登录成功！");
                frame.setVisible(false);//窗口不可见
                hua.StudentShow();//调用一个画板对象中的函数 弹出一个界面
            }else if(te1.getText().isEmpty()&&te2.getText().isEmpty())  
            {  
                JOptionPane.showMessageDialog(this, "请输入账号或密码");
            }else if(te1.getText().isEmpty())  
            {  
                JOptionPane.showMessageDialog(this,"请输入用户名！");  
            }else if(te2.getText().isEmpty())  
            {  
                JOptionPane.showMessageDialog(this,"请输入密码！");
            }else  
            {  
                JOptionPane.showMessageDialog(this,"<html>账户或密码错误！！！<br>请重新输入</html>","错误",JOptionPane.ERROR_MESSAGE);
                //清空输入框  
                Clear(te1, te2);
            }  
 }
        //清空文本框和密码框 
        public void Clear(JTextField te1, JPasswordField te2) {
            te1.setText("");
            te2.setText("");
        }
        //清空密码
        public void aClear(JPasswordField te2)  
        {  
            te2.setText("");  
        }
        public void bClear(JTextField te3)  
        {  
            te3.setText("");  
        }

        
        public  class ButtonListener implements java.awt.event.ActionListener{    //实现ActionListener 接口 implement
            JTextField te1=new JTextField();               //传参
            JPasswordField te2=new JPasswordField();
            Function hua=new Function();                       //一个画板对象
            ButtonListener(JTextField te1,JPasswordField te2) {//重载 窗体上的账号框，密码框传到监听上来
                this.te1=te1;    
                this.te2=te2;
            }
            public ButtonListener(JTextField ID) {
                // TODO Auto-generated constructor stub
            }
            @Override
            public void actionPerformed(ActionEvent e) {
                // TODO Auto-generated method stub
                
            }
        }
        
        public void actionPerformed(ActionEvent ch) {  
            if(ch.getActionCommand()=="查询")  
            {
                Connect.ConnectSQL();//连接数据库
                Connect.GetStudeInfor(ID.getText());//获取ID
                    
                ID.setText("");
                ival.setValueAt(Connect.sID, 0, 0);  
                ival.setValueAt(Connect.sname, 0, 1);
                ival.setValueAt(Connect.Dept, 0 , 2);
                ival.setValueAt(Connect.Java, 0, 3);  
                ival.setValueAt(Connect.Python, 0, 4);  
                ival.setValueAt(Connect.DataStructure, 0, 5);  
            }
              
        }     
}

Connect.java

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

import javax.swing.JOptionPane;
import java.awt.Cursor;
public class Connect {
    static String sID, sname, Dept, Java, Python, DataStructure;
    static Connection Co;  
    static PreparedStatement nValue;  
    static ResultSet ResultInfor; 
    static Statement ST;
    //数据库连接函数
    public static void ConnectSQL() {
        String url = "jdbc:sqlserver://localhost:1433;DatabaseName=master;";//master是自己储存数据的数据库名
        try {
            // 连接数据库
            Co = DriverManager.getConnection(url, "sa", "biubiubiu");//sa是SQL账号，后面是密码
            // 建立Statement对象
            ST = Co.createStatement();
        } catch (SQLException e) {
            e.printStackTrace();
            JOptionPane.showMessageDialog(null,"<html>数据库连接错误！！！<br>请联系管理员修复。</html>","错误",JOptionPane.ERROR_MESSAGE);
        }
    }
    
     public static void GetStudeInfor(String Str) {  
            try {
                // 给?赋值,防止SQL注入， 
                 String sql = "select * from Infor where Stud_ID = ?";
                 nValue = Co.prepareStatement(sql);  
                 nValue.setString(1, Str); 
                 ResultInfor = nValue.executeQuery();  
                 if(ResultInfor.next())     
                 {  
                    //获取学生信息
                    sID = ResultInfor.getString("Stud_ID");  
                    sname = ResultInfor.getString("Stud_Name");
                    Dept = ResultInfor.getString("Stud_Dept");
                    Java = ResultInfor.getString("JavaGrade");  
                    Python = ResultInfor.getString("PythonGrade");  
                    DataStructure = ResultInfor.getString("DataStructureGrade");
                    JOptionPane.showMessageDialog(null, "查询成功！");
                 }else  
                 {  
                     JOptionPane.showMessageDialog(null, "没有此学生！"); 
                 }  
          
             } catch (Exception e1) {  
                // TODO Auto-generated catch block  
                e1.printStackTrace();  
             }  
        } 
}
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原文地址：https://www.cnblogs.com/Mayfly-nymph/p/10192589.html