实现JavaWeb验证码

07-09 09:48 628浏览

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方法一：

1.前端显示

HTML：

<h3>验证码：</h3>
<input type="text" name="validationCode" id="validationCode" placeholder="请输入验证码" lay-verify="required"> 
<img src="validate.jsp" id="validationCode_img" title="看不清?换一个" onclick="loadimage();return false;" name="validationCode_img" align="middle">

JS：

//加载验证码图片，后面加时间可以保证每次页面刷新时验证码也刷新
function loadimage(){
            document.getElementById("validationCode_img").src= "validate.jsp?time=" + new Date().getTime();
        }

2.用一个页面生成验证码图片，这里用JSP页面validate.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<%@page import="java.awt.image.BufferedImage"%>
<%@page import="java.awt.Graphics2D"%>
<%@page import="java.awt.Color"%>
<%@page import="java.awt.Font"%>
<%@page import="javax.imageio.ImageIO"%>
<%@page import="java.util.Random"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>验证码</title>
</head>
<body>
<%
    int width = 60;
    int height = 20;
    // 创建具有可访问图像数据缓冲区的Image
    BufferedImage buffImg = new BufferedImage(width, height,BufferedImage.TYPE_INT_RGB);
    Graphics2D g = buffImg.createGraphics();    
    // 创建一个随机数生成器
    Random random = new Random();    
    g.setColor(Color.WHITE);
    g.fillRect(0, 0, width, height);    
    // 创建字体，字体的大小应该根据图片的高度来定
    Font font = new Font("Times New Roman", Font.PLAIN, 18);
    // 设置字体
    g.setFont(font);    
    // 画边框
    g.setColor(Color.BLACK);
    g.drawRect(0, 0, width - 1, height - 1);    
    // 随机产生160条干扰线
    g.setColor(Color.LIGHT_GRAY);
    for (int i = 0; i < 160; i++) {
        int x = random.nextInt(width);
        int y = random.nextInt(height);
        int x1 = random.nextInt(12);
        int y1 = random.nextInt(12);
        g.drawLine(x, y, x + x1, y + y1);
    }    
    // randomCode 用于保存随机产生的验证码
    StringBuffer randomCode = new StringBuffer();
    int red = 0, green = 0, blue = 0;    
    // 随机产生4位数字的验证码
    for (int i = 0; i < 4; i++) {
        // 得到随机产生的验证码数字
        String strRand = String.valueOf(random.nextInt(10));   
        // 产生随机的颜色分量来构造颜色值
        red = random.nextInt(110);
        green = random.nextInt(50);
        blue = random.nextInt(50);    
        // 用随机产生的颜色将验证码绘制到图像中
        g.setColor(new Color(red, green, blue));
        g.drawString(strRand, 13 * i + 6, 16);    
        randomCode.append(strRand);
    }    
    // 将四位数字的验证码保存到session中
    //HttpSession session = request.getSession();
    session.setAttribute("randomCode", randomCode.toString());    
    // 禁止图像缓存
    response.setHeader("Pragma", "no-cache");
    response.setHeader("Cache-Control", "no-cache");
    response.setDateHeader("Expires", 0);    
    response.setContentType("image/jpeg");
    // 将图像输出到servlet输出流中
    ServletOutputStream sos = response.getOutputStream();
    ImageIO.write(buffImg, "jpeg", sos);
    sos.close();
    //sos = null;
    out.clear();
    out = pageContext.pushBody();
%>
</body>
</html>

3.在validate.jsp页面中生成的验证码其实就是在java后端生成的，所以就存进了session中，我们只需要在用户提交的时候将填写的验证码带到后端，这里我使用的是ajax请求，后端只需要判断验证码是否和session中一样就可以了。

方法二：

html代码：

<div class="layui-form-item">
     <div class="layui-inline">
           <input type="text" name="verity" required lay-verify="required" placeholder="验证码" autocomplete="off" class="layui-input">
     </div>
     <div class="layui-inline">
          <img class="verifyImg" id="verifyImg" onclick="javascript:getvCode();"  />
          <script type="text/javascript">
                  getvCode();//初始化验证码，写在此处减少验证码图片出来的延时
          </script>
     </div>
</div>

js代码：

/**
 * 获取验证码
 * 将验证码写到login.html页面的id = verifyimg 的地方
 */
function getvCode() {
    $("#verifyImg").attr('src',timestamp("verifyCode"));        
}
//为url添加时间戳
 function timestamp(url) {
    var getTimestamp = new Date().getTime();
    if (url.indexOf("?") > -1) {
        url = url + "&timestamp=" + getTimestamp
    } else {
        url = url + "?timestamp=" + getTimestamp
    }
    return url;
};

java代码：

model层

//验证码
public class VerifyCode {
    private String code;
    private byte[] imgBytes;
    private long expireTime;
    public String getCode() {
        return code;
    }
    public void setCode(String code) {
        this.code = code;
    }
    public byte[] getImgBytes() {
        return imgBytes;
    }
    public void setImgBytes(byte[] imgBytes) {
        this.imgBytes = imgBytes;
    }
    public long getExpireTime() {
        return expireTime;
    }
    public void setExpireTime(long expireTime) {
        this.expireTime = expireTime;
    }
}

service层

import java.io.IOException;
import java.io.OutputStream;
import com.hongyang.webglasses.model.VerifyCode;
//验证码生成接口
public interface IVerifyCodeGen {
    /**
     * 生成验证码并返回code，将图片写的os中
     *
     * @param width
     * @param height
     * @param os
     * @return
     * @throws IOException
     */
    String generate(int width, int height, OutputStream os) throws IOException; 
    /**
     * 生成验证码对象
     *
     * @param width
     * @param height
     * @return
     * @throws IOException
     */
    VerifyCode generate(int width, int height) throws IOException;
}

serviceimpl实现

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Random;
import javax.imageio.ImageIO;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Service;
import com.hongyang.webglasses.model.VerifyCode;
import com.hongyang.webglasses.service.IVerifyCodeGen;
import com.hongyang.webglasses.util.RandomUtils;
@Service
public class SimpleCharVerifyCodeGenImpl implements IVerifyCodeGen {
    private static final Logger logger = LoggerFactory.getLogger(SimpleCharVerifyCodeGenImpl.class);
    private static final String[] FONT_TYPES = { "\u5b8b\u4f53", "\u65b0\u5b8b\u4f53", "\u9ed1\u4f53", "\u6977\u4f53", "\u96b6\u4e66" };
    private static final int VALICATE_CODE_LENGTH = 4;    
    /**
     * 生成随机字符
     *
     * @param width
     * @param height
     * @param os
     * @return
     * @throws IOException
     */
    @Override
    public String generate(int width, int height, OutputStream os) throws IOException {
        BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
        Graphics graphics = image.getGraphics();
        fillBackground(graphics, width, height);
        String randomStr = RandomUtils.randomString(VALICATE_CODE_LENGTH);
        createCharacter(graphics, randomStr);
        graphics.dispose();
        //设置JPEG格式
        ImageIO.write(image, "JPEG", os);
        return randomStr;
    }
    /**
     * 验证码生成
     *
     * @param width
     * @param height
     * @return
     */
    @Override
    public VerifyCode generate(int width, int height) {
        VerifyCode verifyCode = null;
        try (
                //将流的初始化放到这里就不需要手动关闭流
                ByteArrayOutputStream baos = new ByteArrayOutputStream();
        ) {
            String code = generate(width, height, baos);
            verifyCode = new VerifyCode();
            verifyCode.setCode(code);
            verifyCode.setImgBytes(baos.toByteArray());
        } catch (IOException e) {
            logger.error(e.getMessage(), e);
            verifyCode = null;
        }
        return verifyCode;
    }
    /**
     * 设置字符颜色大小
     *
     * @param g
     * @param randomStr
     */
    private void createCharacter(Graphics g, String randomStr) {
        char[] charArray = randomStr.toCharArray();
        for (int i = 0; i < charArray.length; i++) {
            //设置RGB颜色算法参数
            g.setColor(new Color(50 + RandomUtils.nextInt(100),
                    50 + RandomUtils.nextInt(100), 50 + RandomUtils.nextInt(100)));
            //设置字体大小，类型
            g.setFont(new Font(FONT_TYPES[RandomUtils.nextInt(FONT_TYPES.length)], Font.BOLD, 26));
            //设置x y 坐标
            g.drawString(String.valueOf(charArray[i]), 15 * i + 5, 19 + RandomUtils.nextInt(8));
        }
    }    
    /**
     * 设置背景颜色及大小，干扰线
     *
     * @param graphics
     * @param width
     * @param height
     */
    private static void fillBackground(Graphics graphics, int width, int height) {
        // 填充背景
        System.setProperty("myColor", "#BBDAEE");
        graphics.setColor(Color.getColor("myColor"));
        //设置矩形坐标x y 为0
        graphics.fillRect(0, 0, width, height);
        // 加入干扰线条
        for (int i = 0; i < 8; i++) {
            //设置随机颜色算法参数
            graphics.setColor(RandomUtils.randomColor(40, 150));
            Random random = new Random();
            int x = random.nextInt(width);
            int y = random.nextInt(height);
            int x1 = random.nextInt(width);
            int y1 = random.nextInt(height);
            graphics.drawLine(x, y, x1, y1);
        }
    }
}

Controller层

@GetMapping("/verifyCode")
    public void verifyCode(HttpServletRequest request, HttpServletResponse response) {
        IVerifyCodeGen iVerifyCodeGen = new SimpleCharVerifyCodeGenImpl();
        try {
            //设置长宽
            VerifyCode verifyCode = iVerifyCodeGen.generate(80, 28);
            String code = verifyCode.getCode();
            //将VerifyCode绑定session，登录控制器可从session中取出从而判断用户填的验证码是否正确
            request.getSession().setAttribute("VerifyCode", code);
            //设置响应头
            response.setHeader("Pragma", "no-cache");
            //设置响应头
            response.setHeader("Cache-Control", "no-cache");
            //在代理服务器端防止缓冲
            response.setDateHeader("Expires", 0);
            //设置响应内容类型
            response.setContentType("image/jpeg");
            response.getOutputStream().write(verifyCode.getImgBytes());
            response.getOutputStream().flush();
        } catch (IOException e) {
        }
    }

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实现JavaWeb验证码

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