本文实例为大家分享了java生成登录随机验证码的具体代码，供大家参考，具体内容如下
验证码工具类： VerifyUtil.java
import java.awt.*;
import java.awt.image.BufferedImage;
import java.util.HashMap;
import java.util.Map;
import java.util.Random;
public class VerifyUtil {
// 验证码字符集
private static final char[] CHARS = {
'0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n',
'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z',
'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N',
'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z'};
// 字符数量
private static final int SIZE = 4;
// 干扰线数量
private static final int LINES = 5;
// 宽度
private static final int WIDTH = 80;
// 高度
private static final int HEIGHT = 40;
// 字体大小
private static final int FONT_SIZE = 30;
/**
* 生成随机验证码及图片
*/
public static Map<String, Object> createImage() {
StringBuffer sb = new StringBuffer();
// 1.创建空白图片
BufferedImage image = new BufferedImage(WIDTH, HEIGHT, BufferedImage.TYPE_INT_RGB);
// 2.获取图片画笔
Graphics graphic = image.getGraphics();
// 3.设置画笔颜色
graphic.setColor(Color.LIGHT_GRAY);
// 4.绘制矩形背景
graphic.fillRect(0, 0, WIDTH, HEIGHT);
// 5.画随机字符
Random ran = new Random();
for (int i = 0; i < SIZE; i++) {
// 取随机字符索引
int n = ran.nextInt(CHARS.length);
// 设置随机颜色
graphic.setColor(getRandomColor());
// 设置字体大小
graphic.setFont(new Font(null, Font.BOLD + Font.ITALIC, FONT_SIZE));
// 画字符
graphic.drawString(CHARS[n] + "", i * WIDTH / SIZE, HEIGHT * 2 / 3);
// 记录字符
sb.append(CHARS[n]);
}
// 6.画干扰线
for (int i = 0; i < LINES; i++) {
// 设置随机颜色
graphic.setColor(getRandomColor());
// 随机画线
graphic.drawLine(ran.nextInt(WIDTH), ran.nextInt(HEIGHT), ran.nextInt(WIDTH), ran.nextInt(HEIGHT));
}
// 7.返回验证码和图片
Map<String, Object> map = new HashMap<>();
//验证码
map.put("code", sb.toString());
//图片
map.put("image", image);
return map;
}
/**
* 随机取色
*/
public static Color getRandomColor() {
Random ran = new Random();
return new Color(ran.nextInt(256), ran.nextInt(256), ran.nextInt(256));
}
}
获取验证码
@GetMapping("/verify-code")
public void getCode(HttpServletResponse response) throws Exception{
Map<String, Object> map = VerifyUtil.createImage();
//将图片输出给浏览器
BufferedImage image = (BufferedImage) map.get("image");
response.setContentType("image/png");
OutputStream os = response.getOutputStream();
ImageIO.write(image, "png", os);
}
页面
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>获取验证码</title>
</head>
<body onload="getVerify()">
<h1>点击图片切换验证码</h1><img src="" alt="更换验证码" height="36" onclick="getVerify()">
</body>
<script>
//获取验证码
function getVerify(){
document.getElementById("img-verify").src="/verify-code?"+Math.random();
}
</script>
</html>
