Kaptcha验证码的生成及配置

            com.github.penggle
            kaptcha
            2.3.2

 
    
        
            
                
                    
                        
                        no
                        
                        120
                        
                        blue
                        
                        40
                        
                        4
                    
                
            

package com.imooc.reader.controller;

import com.google.code.kaptcha.Producer;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;

import javax.annotation.Resource;
import javax.imageio.ImageIO;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.swing.*;
import java.awt.image.BufferedImage;
import java.io.IOException;

@Controller
public class KaptchaController {
    // kaptchaProducer 为配置文件中的 benId
    @Resource
    private Producer kaptchaProducer;

    //生成验证码图片
    @GetMapping("verify_code")
    public void creatVerifyCode(HttpServletRequest request, HttpServletResponse response) throws IOException {
        //响应立即过期
        response.setDateHeader("Expires",0);
        //不缓存任何图片数据
        response.setHeader("Cache-Control","no-store,no-cache,must-revalidate");
        //为了浏览器的兼容性
        response.setHeader("cache-Control","post-check=0,pre-check=0");
        response.setHeader("Pragma","no-cache");
        //返回的内容类型  为图片格式
        response.setContentType("image/png");

        //生成验证码字符文本
        String verifyCode = kaptchaProducer.createText();
        //将验证码存入当前的会话当中
        request.getSession().setAttribute("kaptchaVerifyCode",verifyCode);
        System.out.println(request.getSession().getAttribute("kaptchaVerifyCode"));

        //CreatImage用于创建验证码图片
        BufferedImage image = kaptchaProducer.createImage(verifyCode);
        //图片为二进制所以使用outPutStream
        ServletOutputStream out = response.getOutputStream();
        //将图片从服务器通过响应发送到客户端浏览器，客户端浏览器收到图片数据为png格式的图片，就当作图片进行展示
        ImageIO.write(image,"png",out);

        out.flush();
        out.close();
    }
}