update:demo12

com/study/demo12/VerifyCodeFrame.java

@@ -0,0 +1,38 @@
+package com.study.demo12;
+
+import java.awt.*;
+import java.awt.event.*;
+
+public class VerifyCodeFrame extends Frame {
+    private Label codeLabel;
+
+    public VerifyCodeFrame() {
+        setTitle("验证码生成窗口");
+        setSize(300, 150);
+        setLayout(new FlowLayout());
+
+        Button codeButton = new Button("获取验证码");
+        codeLabel = new Label("点击按钮获取验证码");
+
+        codeButton.addActionListener(e -> {
+            String timestamp = String.valueOf(System.currentTimeMillis());
+            String last4Digits = timestamp.substring(timestamp.length() - 4);
+            codeLabel.setText("CODE" + last4Digits);
+        });
+
+        addWindowListener(new WindowAdapter() {
+            @Override
+            public void windowClosing(WindowEvent e) {
+                System.exit(0);
+            }
+        });
+
+        add(codeButton);
+        add(codeLabel);
+        setVisible(true);
+    }
+
+    public static void main(String[] args) {
+        new VerifyCodeFrame();
+    }
+}