Java | 实现验证码 - 代码天地

前端

<html>
<head>
    <title>登录</title>
    <script>
        onload = function () {
            imgCode.onclick = function () {
                this.src = "valid?" + new Date().getTime();
            }
        }
    </script>
</head>
<body>
<form action="login">
    <p>
        <label for="name">用户名:</label>
        <input type="text" name="name" id="name">
    </p>
    <p>
        <label for="password">密码:</label>
        <input type="password" name="password" id="password">
    </p>
    <p>
        <label for="code">验证码:</label>
        <input type="text" name="code" id="code">
        <img id="imgCode" src="valid" title="看不清楚，点击换一张">
    </p>
    <p>
        <button formmethod="post">登陆</button>
        <button type="reset">重置</button>
    </p>
</form>
</body>
</html>

controller

package com.java.controller;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

import javax.imageio.ImageIO;
import javax.servlet.http.HttpSession;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.OutputStream;
import java.util.Random;

@Controller
public class ValidCodeController {
    @RequestMapping("valid")
    public void validCode(HttpSession session, OutputStream out) throws Exception {
        Random rnd = new Random();
        String code = "";
        for (int i = 0; i < 4; i++) {
        	// 0-61
            int n = rnd.nextInt(62);
            if (n < 10) {
            	// 0-9
                code += n;
            } else if (n < 36) {
            	// 10-35
                code += (char) (n - 10 + 'A');
            } else {
            	// 36-61
                code += (char) (n - 36 + 'a');
            }
        }
        session.setAttribute("code", code);
        BufferedImage image = new BufferedImage(
                100, 25, BufferedImage.TYPE_INT_RGB);
        Graphics gra = image.getGraphics();
        // 设置背景色
        gra.setColor(Color.yellow);
        // 绘制边框
        gra.fillRect(2, 2, 96, 21);
        // 设置字体
        gra.setFont(new Font("Times New Roman", Font.BOLD | Font.ITALIC, 20));
        for (int i = 0; i < 4; i++) {
            Color clr = new Color(rnd.nextInt(256),
                    rnd.nextInt(256), rnd.nextInt(256));
            //设置字体颜色
            gra.setColor(clr); 
            //绘制文字
            gra.drawString(code.substring(i, i + 1), 15 + 20 * i, 18); 
        }
        //绘制干扰线
        for (int i = 0; i < 5; i++) {
            Color clr = new Color(rnd.nextInt(256),
                    rnd.nextInt(256), rnd.nextInt(256));
            //设置线条颜色
            gra.setColor(clr); 
            //设置线条粗细
            Graphics2D g2d = (Graphics2D) gra;
            g2d.setStroke(new BasicStroke(1 + rnd.nextFloat() + rnd.nextInt(2)));
            gra.drawLine(rnd.nextInt(100), rnd.nextInt(25),
                    rnd.nextInt(100), rnd.nextInt(25));
        }
        ImageIO.write(image, "jpeg", out);
        out.close();
    }
}

阿壮Jonsson

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Java | 实现验证码

前端

controller

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