Javaweb登录验证码代码
时间: 2023-04-12 12:00:34 浏览: 92
以下是一个简单的 JavaWeb 登录验证码代码:
```java
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.util.Random;
import javax.imageio.ImageIO;
import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
public class VerifyCodeServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
private int width = 100; // 验证码图片的默认宽度
private int height = 30; // 验证码图片的默认高度
private int codeCount = 4; // 验证码字符个数
private int lineCount = 20; // 干扰线数量
private String codeChars = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"; // 验证码字符集合
private BufferedImage buffImg = null; // 验证码图片
private Random random = new Random();
@Override
public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException {
// 设置响应头信息
response.setHeader("Pragma", "no-cache");
response.setHeader("Cache-Control", "no-cache");
response.setDateHeader("Expires", 0);
// 设置响应内容类型
response.setContentType("image/jpeg");
// 创建验证码图片
createImage(request.getSession());
try {
// 输出验证码图片到页面
ServletOutputStream sos = response.getOutputStream();
ImageIO.write(buffImg, "jpeg", sos);
sos.close();
} catch (Exception e) {
e.printStackTrace();
}
}
/**
* 创建验证码图片
*
* @param session
*/
private void createImage(HttpSession session) {
// 创建一个 BufferedImage 对象,用于在上面绘制验证码图片
buffImg = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
Graphics g = buffImg.getGraphics();
// 设置背景色
g.setColor(new Color(255, 255, 255));
g.fillRect(0, 0, width, height);
// 设置字体
Font font = new Font("Fixedsys", Font.BOLD, 20);
g.setFont(font);
// 绘制干扰线
for (int i = 0; i < lineCount; i++) {
int xs = random.nextInt(width);
int ys = random.nextInt(height);
int xe = xs + random.nextInt(width / 8);
int ye = ys + random.nextInt(height / 8);
g.setColor(getRandomColor());
g.drawLine(xs, ys, xe, ye);
}
// 绘制验证码
StringBuilder sb = new StringBuilder();
for (int i = 0; i < codeCount; i++) {
String code = String.valueOf(codeChars.charAt(random.nextInt(codeChars.length())));
sb.append(code);
g.setColor(getRandomColor());
g.drawString(code, 20 * i + 10, 25);
}
// 将验证码字符串保存到 Session 中
session.setAttribute("verifyCode", sb.toString());
}
/**
* 获取随机颜色
*
* @return
*/
private Color getRandomColor() {
int r = random.nextInt(255);
int g = random.nextInt(255);
int b = random.nextInt(255);
return new Color(r, g, b);
}
}
```
这段代码可以生成一个简单的验证码图片,用于在 JavaWeb 登录页面中进行验证码验证。