java实现滑块验证码
时间: 2023-06-29 16:05:46 浏览: 92
滑块验证码是一种常见的人机交互验证方式,主要用于防止恶意攻击和机器人攻击。下面是一个简单的Java实现滑块验证码的示例代码:
1. 首先,需要在前端页面上实现一个滑块组件,并在后台生成一个随机的验证码图片。
2. 然后,用户需要按住滑块并将其拖动到正确的位置,以验证自己是一个真正的人类用户。
3. 在后台,需要验证用户拖动滑块的位置是否正确,以确保用户通过了验证。
下面是一个基于Spring Boot框架的简单示例代码:
1. 在前端页面中添加如下代码:
```html
<div class="slider-container">
<div class="slider-background"></div>
<div class="slider-handle"></div>
</div>
```
2. 在后台代码中,需要生成一个随机的验证码图片,并将验证码信息保存在Session中,以便后续验证。以下是一个简单的验证码生成器示例代码:
```java
import java.awt.*;
import java.awt.image.BufferedImage;
import java.util.Random;
public class CaptchaGenerator {
private static final int IMAGE_WIDTH = 200;
private static final int IMAGE_HEIGHT = 80;
private static final int LINE_COUNT = 20;
private static final int CHAR_COUNT = 4;
private static final String CHAR_SET = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
private static final int CHAR_SPACE = 20;
private static final int CHAR_FONT_SIZE = 50;
public static BufferedImage generate(String captcha) {
BufferedImage image = new BufferedImage(IMAGE_WIDTH, IMAGE_HEIGHT, BufferedImage.TYPE_INT_RGB);
Graphics2D g = image.createGraphics();
g.setColor(Color.WHITE);
g.fillRect(0, 0, IMAGE_WIDTH, IMAGE_HEIGHT);
g.setColor(Color.BLACK);
Random random = new Random();
for (int i = 0; i < LINE_COUNT; i++) {
int x1 = random.nextInt(IMAGE_WIDTH);
int y1 = random.nextInt(IMAGE_HEIGHT);
int x2 = random.nextInt(IMAGE_WIDTH);
int y2 = random.nextInt(IMAGE_HEIGHT);
g.drawLine(x1, y1, x2, y2);
}
Font font = new Font("Arial", Font.BOLD, CHAR_FONT_SIZE);
g.setFont(font);
int x = (IMAGE_WIDTH - CHAR_COUNT * CHAR_FONT_SIZE - (CHAR_COUNT - 1) * CHAR_SPACE) / 2;
int y = (IMAGE_HEIGHT - CHAR_FONT_SIZE) / 2 + CHAR_FONT_SIZE;
for (int i = 0; i < captcha.length(); i++) {
char c = captcha.charAt(i);
g.drawString(String.valueOf(c), x, y);
x += CHAR_FONT_SIZE + CHAR_SPACE;
}
g.dispose();
return image;
}
public static String generateCaptcha() {
Random random = new Random();
StringBuilder sb = new StringBuilder();
for (int i = 0; i < CHAR_COUNT; i++) {
char c = CHAR_SET.charAt(random.nextInt(CHAR_SET.length()));
sb.append(c);
}
return sb.toString();
}
}
```
3. 在Controller中,需要处理滑块验证请求,并进行验证码验证。以下是一个简单的Controller示例代码:
```java
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.*;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.awt.image.BufferedImage;
import java.io.IOException;
@Controller
public class CaptchaController {
@GetMapping("/captcha")
public void captcha(HttpServletRequest request, HttpServletResponse response) throws IOException {
String captcha = CaptchaGenerator.generateCaptcha();
BufferedImage image = CaptchaGenerator.generate(captcha);
HttpSession session = request.getSession();
session.setAttribute("captcha", captcha);
response.setContentType("image/png");
response.getOutputStream().write(ImageUtil.toByteArray(image));
}
@PostMapping("/captcha/verify")
@ResponseBody
public boolean verify(@RequestParam String captcha, HttpSession session) {
String expectedCaptcha = (String) session.getAttribute("captcha");
return captcha.equals(expectedCaptcha);
}
}
```
以上是一个简单的Java实现滑块验证码的示例代码。为了实现更好的安全性,实际应用中需要进一步加强验证机制,例如添加时间限制、IP限制等。