利用Java进行验证码的实现——算数验证码

我主要使用使用 Java Swing 库创建一个 GUI 窗口，然后在窗口中显示生成的算术验证码图片，并提供一个文本框和一个按钮，输入验证码并验证显示结果。

代码如下：

package calculate;
import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.image.BufferedImage;
public class ArithmeticValidateCodeExample extends JFrame implements ActionListener {private static final int WIDTH = 100;     // 图片宽度private static final int HEIGHT = 80;     // 图片高度private static final int FONT_SIZE = 20;  // 字体大小private BufferedImage image;              // 验证码图片private String arithmeticExpression;       // 算术表达式private int arithmeticResult;              // 算术表达式的结果private JLabel label;                      // 显示算术表达式和"请输入验证码结果"private JTextField textField;              // 获取用户输入的结果public ArithmeticValidateCodeExample() {// 生成算术表达式和结果arithmeticExpression = generateArithmeticExpression();arithmeticResult = calculateArithmeticExpression(arithmeticExpression);// 创建验证码图片image = generateValidateCodeImage(arithmeticExpression);// 设置JFrame的属性setSize(WIDTH + 80, HEIGHT + 100);  // 加上100的高度为了留出空间放"请输入验证码结果"和输入框setLocationRelativeTo(null);setTitle("算数验证码");// 创建一个JLabel用于显示验证码图片JLabel imageLabel = new JLabel(new ImageIcon(image));getContentPane().add(imageLabel, BorderLayout.NORTH);// 添加"请输入验证码结果"和输入框及"验证"按钮label = new JLabel("请输入验证码结果：");textField = new JTextField(8);JButton button = new JButton("验证");button.addActionListener(this);JPanel inputPanel = new JPanel(new FlowLayout());inputPanel.add(label);inputPanel.add(textField);inputPanel.add(button);getContentPane().add(inputPanel, BorderLayout.CENTER);}public static void main(String[] args) {ArithmeticValidateCodeExample example = new ArithmeticValidateCodeExample();example.setVisible(true);example.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);}@Overridepublic void actionPerformed(ActionEvent e) {String userInput = textField.getText();int userResult = Integer.parseInt(userInput);if (userResult == arithmeticResult) {JOptionPane.showMessageDialog(null, "验证通过！");} else {JOptionPane.showMessageDialog(null, "验证失败！");}}private static String generateArithmeticExpression() {int number1 = (int) (Math.random() * 100);int number2 = (int) (Math.random() * 100);int operator = (int) (Math.random() * 4);char operatorChar;switch (operator) {case 0:operatorChar = '+';break;case 1:operatorChar = '-';break;case 2:operatorChar = '*';break;case 3:operatorChar = '/';break;default:operatorChar = '+';}return number1 + " " + operatorChar + " " + number2;}private static int calculateArithmeticExpression(String arithmeticExpression) {String[] components = arithmeticExpression.split(" ");int number1 = Integer.parseInt(components[0]);char operator = components[1].charAt(0);int number2 = Integer.parseInt(components[2]);int result;switch (operator) {case '+':result = number1 + number2;break;case '-':result = number1 - number2;break;case '*':result = number1 * number2;break;case '/':result = number1 / number2;break;default:result = 0;}return result;}private static BufferedImage generateValidateCodeImage(String arithmeticExpression) {BufferedImage image = new BufferedImage(WIDTH, HEIGHT, BufferedImage.TYPE_INT_RGB);Graphics2D g = image.createGraphics();// 设置背景颜色g.setColor(Color.WHITE);g.fillRect(0, 0, WIDTH, HEIGHT);// 设置字体样式和大小Font font = new Font(Font.DIALOG, Font.BOLD, FONT_SIZE);g.setFont(font);// 设置验证码文本颜色g.setColor(Color.BLACK);// 绘制算术表达式的文本g.drawString(arithmeticExpression, 10, HEIGHT / 2 - FONT_SIZE);// 添加干扰线for (int i = 0; i < 5; i++) {int x1 = (int) (Math.random() * WIDTH);int y1 = (int) (Math.random() * HEIGHT);int x2 = (int) (Math.random() * WIDTH);int y2 = (int) (Math.random() * HEIGHT);g.drawLine(x1, y1, x2, y2);}// 噪点数量int noiseCount = WIDTH * HEIGHT / 5;for (int i = 0; i < noiseCount; i++) {int x = (int) (Math.random() * WIDTH);int y = (int) (Math.random() * HEIGHT);int rgb = getRandomColor().getRGB();image.setRGB(x, y, rgb);}g.dispose();return image;}private static Color getRandomColor() {int r = (int) (Math.random() * 256);int g = (int) (Math.random() * 256);int b = (int) (Math.random() * 256);return new Color(r, g, b);}
}