验证码的生成以及使用

工具类：

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.util.concurrent.TimeUnit;

import javax.imageio.ImageIO;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

/**
 * 生成验证码工具
 * @Author ChenWenChao
 */
@RestController
@RequestMapping("/code")
public class CodeUtils {
    @Autowired
    private RedisTemplate redisTemplate;

    /**
     * 生成验证码
     * @param request
     * @param response
     * @throws Exception
     */
    @GetMapping("/verificationCode")
    public void verificationCode(HttpServletRequest request, HttpServletResponse response) throws Exception {
        response.setContentType("image/jpeg");
        HttpSession session = request.getSession();
        int width = 60;
        int height = 20;
        //设置浏览器不要缓存此图片
        response.setHeader("Pragma", "No-cache");
        response.setHeader("Cache-Control", "no-cache");
        response.setDateHeader("Expires", 0);
        //创建内存图像并获得其图形上下文
        BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
        Graphics g = image.getGraphics();
        //产生随机验证码
        //定义验证码的字符表(去除01OI降低输错率)
        String chars = "23456789ABCDEFGHJKLMNPQRSTUVWXYZ";
        char[] rands = new char[4];
        for (int i = 0; i < 4; i++) {
            int rand = (int) (Math.random() * 32);
            rands[i] = chars.charAt(rand);
        }
        //产生图像
        //画背景
        g.setColor(new Color(0xDCDCDC));
        g.fillRect(0, 0, width, height);
        //随机产生120个干扰点
        for (int i = 0; i < 120; i++) {
            int x = (int) (Math.random() * width);
            int y = (int) (Math.random() * height);
            int red = (int) (Math.random() * 255);
            int green = (int) (Math.random() * 255);
            int blue = (int) (Math.random() * 255);
            g.setColor(new Color(red, green, blue));
            g.drawOval(x, y, 1, 0);
        }
        g.setColor(Color.BLACK);
        g.setFont(new Font(null, Font.ITALIC | Font.BOLD, 18));
        //在不同的高度上输出验证码的不同字符
        g.drawString("" + rands[0], 1, 17);
        g.drawString("" + rands[1], 16, 15);
        g.drawString("" + rands[2], 31, 18);
        g.drawString("" + rands[3], 46, 16);
        g.dispose();
        //将图像输出到客户端
        ServletOutputStream sos = response.getOutputStream();
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        ImageIO.write(image, "JPEG", baos);
        byte[] buffer = baos.toByteArray();
        response.setContentLength(buffer.length);
        sos.write(buffer);
        baos.close();
        sos.close();
        //将验证码放到session中
        //session.setAttribute("verificationCode", new String(rands));
        //将验证码缓存到redis中(键名用ip来区分)
        redisTemplate.opsForValue().set("verification_code:" + IpUtils.getRealIp(request),
                new String(rands), 600L, TimeUnit.SECONDS);
    }
}

　　

用法：

<img onclick="this.src='/code/verificationCode'+'?t='+new Date().getTime()" src="/code/verificationCode"/>

 

@Autowired
private RedisTemplate<Object, Object> redisTemplate;

//以下代码在登录方法里调用
//String verificationCode = (String) request.getSession().getAttribute("verificationCode");
String verificationCode ="0000";
if (redisTemplate.hasKey("verification_code:" + IpUtils.getRealIp(request))) {
    verificationCode = (String) redisTemplate.opsForValue().get("verification_code:" + IpUtils.getRealIp(request));
}
if (!code.equalsIgnoreCase(verificationCode)) {
    //抛的异常大家根据自己公司封装的自定义异常来使用
    throw new ResultInfo(ResultUtils.error("验证码错误",""));
}