登录页面，库存管理页面

src/main/java/com/example/Main.java

@@ -4,39 +4,66 @@ import javax.swing.*;
 import java.awt.*;
 import java.awt.event.ActionEvent;
 import java.awt.event.ActionListener;
+import java.sql.ResultSet;
+import java.sql.SQLException;
+import java.util.Random;
 
 public class Main extends JFrame implements ActionListener {
 
-    JButton jb1,jb2,jb3;
-
+    JButton jb1,jb2;
+    JTextField tf1,tf3;
+    JPasswordField tf2;
+    JLabel jl1,jl2,jl3,jl4,jl5;
+    Random rand = new Random();
     Main(){
-        super("超市进销存信息管理系统");
-        jb1=new JButton("进货商品信息");
-        jb2=new JButton("销售商品信息");
-        jb3=new JButton("库存商品信息");
+        super("登录");
+        jb1=new JButton("登录");
+        jb2=new JButton("取消");
+        tf1=new JTextField(6);
+        tf2=new JPasswordField(6);
+        tf3=new JTextField(6);
+        jl1=new JLabel("用户名",JLabel.CENTER);
+        jl2=new JLabel("密码",JLabel.CENTER);
+        jl3=new JLabel("验证码",JLabel.CENTER);
+        jl4=new JLabel("验证码：",JLabel.CENTER);
+        jl5=new JLabel("",JLabel.CENTER);
         jb1.addActionListener(this);
         jb2.addActionListener(this);
-        jb3.addActionListener(this);
-        setLayout(new GridLayout(3,3));
+        setLayout(new GridLayout(5,2));
         setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
-        add(jb1);
-        add(jb2);
-        add(jb3);
-        setBounds(100,100,500,500);
+        add(jl1);add(tf1);
+        add(jl2);add(tf2);
+        add(jl3);add(tf3);
+        add(jl4);add(jl5);
+        add(jb1);add(jb2);
+        jl5.setText(Integer.toString(rand.nextInt(100)+100));
+        setBounds(500,100,500,500);
         setVisible(true);
     }
 
     @Override
     public void actionPerformed(ActionEvent e) {
+
         if(e.getSource()==jb1){
-            new InventoryProductManagement();//进入进货商品信息管理系统
-            setVisible(false);
+            Jdbc jdbc = new Jdbc();
+            String sql = "select * from user where username='"+tf1.getText()+"' and password='"+tf2.getText()+"'"; ;
+            try {
+                ResultSet rs = jdbc.query(sql);
+                jdbc.close();
+                if(rs.next()&&tf3.getText().equals(jl5.getText())) {
+                    JOptionPane.showMessageDialog(null, "登录成功");
+                    new Home();
+                    this.setVisible(false);
+                }
+                else{
+                    JOptionPane.showMessageDialog(null,"登录失败");
+                    jl5.setText(Integer.toString(rand.nextInt(100)+100));
+                }
+            } catch (SQLException ex) {
+                throw new RuntimeException(ex);
+            }
         }else if(e.getSource()==jb2){
-            new SalesProductManagement();//进入销售商品信息管理系统
-            setVisible(false);
-        }else if(e.getSource()==jb3){
-            new StockProductManagement();//进入库存商品信息管理系统
-            setVisible(false);
+            System.exit(0);
         }
     }