图片验证码案例

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创建工具类:

package com.lyt.util;

import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Date;
import java.util.Random;

/**
 * 验证码生成器
 *
 * @author
 */
public class ValidateCode {
    // 图片的宽度。
    private int width = 160;
    // 图片的高度。
    private int height = 40;
    // 验证码字符个数
    private int codeCount = 5;
    // 验证码干扰线数
    private int lineCount = 150;
    // 验证码
    private String code = null;
    // 验证码图片Buffer
    private BufferedImage buffImg = null;

    // 验证码范围,去掉0(数字)和O(拼音)容易混淆的(小写的1和L也可以去掉,大写不用了)
    private char[] codeSequence = {'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J',
            'K', 'L', 'M', 'N', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W',
            'X', 'Y', 'Z', '1', '2', '3', '4', '5', '6', '7', '8', '9'};

    /**
     * 默认构造函数,设置默认参数
     */
    public ValidateCode() {
        this.createCode();
    }

    /**
     * @param width  图片宽
     * @param height 图片高
     */
    public ValidateCode(int width, int height) {
        this.width = width;
        this.height = height;
        this.createCode();
    }

    /**
     * @param width     图片宽
     * @param height    图片高
     * @param codeCount 字符个数
     * @param lineCount 干扰线条数
     */
    public ValidateCode(int width, int height, int codeCount, int lineCount) {
        this.width = width;
        this.height = height;
        this.codeCount = codeCount;
        this.lineCount = lineCount;
        this.createCode();
    }

    public void createCode() {
        int x = 0, fontHeight = 0, codeY = 0;
        int red = 0, green = 0, blue = 0;

        x = width / (codeCount + 2);//每个字符的宽度(左右各空出一个字符)
        fontHeight = height - 2;//字体的高度
        codeY = height - 4;

        // 图像buffer
        buffImg = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
        Graphics2D g = buffImg.createGraphics();
        // 生成随机数
        Random random = new Random();
        // 将图像填充为白色
        g.setColor(Color.WHITE);
        g.fillRect(0, 0, width, height);
        // 创建字体,可以修改为其它的
        Font font = new Font("Fixedsys", Font.PLAIN, fontHeight);
//        Font font = new Font("Times New Roman", Font.ROMAN_BASELINE, fontHeight);
        g.setFont(font);

        for (int i = 0; i < lineCount; i++) {
            // 设置随机开始和结束坐标
            int xs = random.nextInt(width);//x坐标开始
            int ys = random.nextInt(height);//y坐标开始
            int xe = xs + random.nextInt(width / 8);//x坐标结束
            int ye = ys + random.nextInt(height / 8);//y坐标结束

            // 产生随机的颜色值，让输出的每个干扰线的颜色值都将不同。
            red = random.nextInt(255);
            green = random.nextInt(255);
            blue = random.nextInt(255);
            g.setColor(new Color(red, green, blue));
            g.drawLine(xs, ys, xe, ye);
        }

        // randomCode记录随机产生的验证码
        StringBuffer randomCode = new StringBuffer();
        // 随机产生codeCount个字符的验证码。
        for (int i = 0; i < codeCount; i++) {
            String strRand = String.valueOf(codeSequence[random.nextInt(codeSequence.length)]);
            // 产生随机的颜色值，让输出的每个字符的颜色值都将不同。
            red = random.nextInt(255);
            green = random.nextInt(255);
            blue = random.nextInt(255);
            g.setColor(new Color(red, green, blue));
            g.drawString(strRand, (i + 1) * x, codeY);
            // 将产生的四个随机数组合在一起。
            randomCode.append(strRand);
        }
        // 将四位数字的验证码保存到Session中。
        code = randomCode.toString();
    }

    public void write(String path) throws IOException {
        OutputStream sos = new FileOutputStream(path);
        this.write(sos);
    }

    public void write(OutputStream sos) throws IOException {
        ImageIO.write(buffImg, "png", sos);
        sos.close();
    }

    public BufferedImage getBuffImg() {
        return buffImg;
    }

    public String getCode() {
        return code;
    }

    /**
     * 测试函数,默认生成到d盘
     * @param args
     */
    public static void main(String[] args) {
        ValidateCode vCode = new ValidateCode(160,40,5,150);
        try {
            String path="D:/"+new Date().getTime()+".png";
            System.out.println(vCode.getCode()+" >"+path);
            vCode.write(path);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

通过controller 层进行调用:

package com.lyt.conntroller;


import com.lyt.util.ValidateCode;
import org.springframework.web.bind.annotation.CrossOrigin;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

@RestController
@RequestMapping("/setPric")
@CrossOrigin
public class ValidateCodes {

    /**
     * 响应验证码页面
     * @return
     */
    @RequestMapping(value="/validateCode")
    public String validateCode(HttpServletRequest request, HttpServletResponse response) throws Exception{
        // 设置响应的类型格式为图片格式
        response.setContentType("image/jpeg");
        //禁止图像缓存。
        response.setHeader("Pragma", "no-cache");
        response.setHeader("Cache-Control", "no-cache");
        response.setDateHeader("Expires", 0);

        HttpSession session = request.getSession();

        ValidateCode vCode = new ValidateCode(120,40,5,100);
        session.setAttribute("code", vCode.getCode());
        vCode.write(response.getOutputStream());
        System.out.println(vCode.getCode());
        return null;
    }

}

创建jsp 进行测试:

<%--
  Created by IntelliJ IDEA.
  User: 01391056
  Date: 2018/9/26
  Time: 14:28
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>Title</title>
</head>
<body>


<div class="form-group  col-lg-6">
    <label for="id" class="col-sm-4 control-label">
        验证码:
    </label>
    <div class="col-sm-8">
        <input type="text" id="code" name="code" class="form-control" style="width:250px;"/>
        <img id="imgObj" alt="验证码" src="/article/validateCode" onclick="changeImg()"/>
        <a href="#" onclick="changeImg()">换一张</a>
    </div>
</div>

<script type="text/javascript">
    // 刷新图片
    function changeImg() {
        var imgSrc = $("#imgObj");
        var src = imgSrc.attr("src");
        imgSrc.attr("src", changeUrl(src));
    }
    //为了使每次生成图片不一致，即不让浏览器读缓存，所以需要加上时间戳
    function changeUrl(url) {
        var timestamp = (new Date()).valueOf();
        var index = url.indexOf("?",url);
        if (index > 0) {
            url = url.substring(index, url.indexOf(url, "?"));
        }
        if ((url.indexOf("&") >= 0)) {
            url = url + "×tamp=" + timestamp;
        } else {
            url = url + "?timestamp=" + timestamp;
        }
        return url;
    }
</script>


</body>
</html>