Java生成随机图片验证码-蒲公英云

转自： https://blog.csdn.net/qq_32963841/article/details/103182827

程序员把地府后台管理系统做出来了，还有3.0版本！12月7号最新消息：已在开发中有github地址: https://blog.csdn.net/m0_37609579/article/details/103108301

《吊打面试官》系列-Redis基础知识: https://blog.csdn.net/qq_35190492/article/details/102841400

java中的Maven项目的两种打包方法: https://blog.csdn.net/u010910436/article/details/48290323

eclipse中打包maven项目完成流程: https://blog.csdn.net/qq_26442553/article/details/78693236

eclipse maven 打war包的几种方式: https://www.cnblogs.com/qlqwjy/p/8231032.html

eclipse通过maven install打包: https://blog.csdn.net/yhblog/article/details/83818158

Eclipse中打包maven项目-war包方式: https://www.cnblogs.com/huangjinyong/p/9223934.html

Eclipse中Maven打包程序并在Linux中运行: https://cloud.tencent.com/developer/article/1080059

Eclipse中给maven项目打jar包: https://www.jianshu.com/p/a6bb81bb38d7

效果如图

前台html代码

验证码：

注释：此处的src=”/qos/dog/getVerifyCodeImg” SpringBoot页面展示Thymeleaf的语法
前台js代码

function change() {
var verifyCode = document.getElementById(“verifyCodeImg”);
verifyCode.src = “/qos/dog/getVerifyCodeImg?time=” + Math.random(1000);
}

/*-*/

/qos/dog/ 这里的路径是需要换成自己的哦

验证代码，在controller里面新建一个util文件夹，然后放入VerifyCodeUtil.java

代码如下

package com.paladin.qos.util;

import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.Random;

public class VerifyCodeUtil {

private static final Random random = new Random();  
private static final String\[\] fontNames = \{"宋体", "华文楷体", "黑体", "Georgia", "微软雅黑", "楷体\_GB2312"\};  
public static String drawImage(ByteArrayOutputStream output) \{  
    String code = "";  
    int width = 50;  
    int height = 25;  
    //创建图片缓冲区  
    BufferedImage bi = new BufferedImage(width, height, BufferedImage.TYPE\_3BYTE\_BGR);  
    Graphics2D g = bi.createGraphics();  
    //设置背景颜色  
    g.setBackground(new Color(255, 255, 255));  
    g.clearRect(0, 0, width, height);  
    StringBuilder stringBuilder = new StringBuilder();  
    //这里只画入四个字符  
    for (int i = 0; i < 4; i++) \{  
        String s = randomChar() + "";      //随机生成字符，因为只有画字符串的方法，没有画字符的方法，所以需要将字符变成字符串再画  
        stringBuilder.append(s);           //添加到StringBuilder里面  
        float x = i \* 1.0F \* width / 4;   //定义字符的x坐标  
        g.setFont(randomFont());           //设置字体，随机  
        g.setColor(randomColor());         //设置颜色，随机  
        g.drawString(s, x, height - 5);  
    \}  
    code = stringBuilder.toString();//获取验证码字符串  
    //定义干扰线  
    //定义干扰线的数量（3-5条）int num = random.nextInt(max)%(max-min+1) + min;  
    int num = random.nextInt(5) % 3 + 3;  
    Graphics2D graphics = (Graphics2D) bi.getGraphics();  
    for (int i = 0; i < num; i++) \{  
        int x1 = random.nextInt(width);  
        int y1 = random.nextInt(height);  
        int x2 = random.nextInt(width);  
        int y2 = random.nextInt(height);  
        graphics.setColor(randomColor());  
        graphics.drawLine(x1, y1, x2, y2);  
    \}  
    // 释放图形上下文  
    g.dispose();  
    try \{  
        ImageIO.write(bi, "jpg", output);  
    \} catch (IOException e) \{  
        e.printStackTrace();  
    \}  
    return code;//为了方便取值，直接返回code，  
\}  
//随机字体  
private static Font randomFont() \{  
    int index = random.nextInt(fontNames.length);  
    String fontName = fontNames\[index\];  
    int style = random.nextInt(4);         //随机获取4种字体的样式  
    int size = random.nextInt(20) % 6 + 15;    //随机获取字体的大小(10-20之间的值)  
    return new Font(fontName, style, size);  
\}  
//随机颜色  
private static Color randomColor() \{  
    int r = random.nextInt(225);  
    int g = random.nextInt(225);  
    int b = random.nextInt(225);  
    return new Color(r, g, b);  
\}  
//随机字符  
private static char randomChar() \{  
    //A-Z,a-z,0-9,可剔除一些难辨认的字母与数字  
    String str = "0123456789ABCdefghiDEFGHIJopPQRVWXYZabcjklSTUmnqrstKLMNOvuwxyz";  
    return str.charAt(random.nextInt(str.length()));  
\}

}
最后，在controller里面引用

@RequestMapping("/getVerifyCodeImg")  
@ResponseBody  
public void getVerifyCodeImg(HttpServletResponse response, HttpSession session) \{  
    ByteArrayOutputStream output = new ByteArrayOutputStream();  
    String code = VerifyCodeUtil.drawImage(output);  
    //将验证码文本直接存放到session中  
    session.setAttribute("verifyCode", code);  
    try \{  
        ServletOutputStream out = response.getOutputStream();  
        output.writeTo(out);  
    \} catch (IOException e) \{  
        e.printStackTrace();  
    \}  
\}