java生成验证码图片

一、绘制验证码工具类

package com.personalbutler.util;

import java.awt.*;
import java.awt.image.BufferedImage;
import java.util.Random;

/**
* @description: 生成验证码工具类
* @projectName:personal
* @author:yuzonghao
* @createTime:2020/3/7 12:57
*/
public class VerifyCodeUtil {

private static String baseNumLetter = "123456789abcdefghijklmnopqrstuvwxyzABCDEFGHJKLMNPQRSTUVWXYZ";
private static String font = "微软雅黑";

/**
* description: 绘制验证码图片,返回验证码文本内容
* param [width, height, verifyImg]
* author yuzonghao
* createTime 2020/3/7 13:06
**/
public static  String drawRandomText(int width, int height, BufferedImage verifyImg) {

Graphics2D graphics = (Graphics2D) verifyImg.getGraphics();
graphics.setColor(Color.WHITE);//设置画笔颜色-验证码背景色
graphics.fillRect(0, 0, width, height);//填充背景
graphics.setFont(new Font(font, Font.BOLD, 30));

StringBuffer sBuffer = new StringBuffer();
int x = 10;  //旋转原点的 x 坐标
String ch = "";
Random random = new Random();
for(int i = 0;i < 4;i++){
graphics.setColor(getRandomColor());
//设置字体旋转角度
int degree = random.nextInt() % 30;  //角度小于30度
int dot = random.nextInt(baseNumLetter.length());
ch = baseNumLetter.charAt(dot) + "";
sBuffer.append(ch);
//正向旋转
graphics.rotate(degree * Math.PI / 180, x, 45);
graphics.drawString(ch, x, 45);
//反向旋转
graphics.rotate(-degree * Math.PI / 180, x, 45);
x += 48;
}

//画干扰线
for (int i = 0; i <30; i++) {
// 设置随机颜色
graphics.setColor(getRandomColor());
// 随机画线
graphics.drawLine(random.nextInt(width), random.nextInt(height),
random.nextInt(width), random.nextInt(height));

}

//添加噪点
for(int i=0;i<60;i++){
int x1 = random.nextInt(width);
int y1 = random.nextInt(height);
graphics.setColor(getRandomColor());
graphics.fillRect(x1, y1, 2,2);

}
return sBuffer.toString();
}

/**
* description: 获取随机颜色
* param []
* author yuzonghao
* createTime 2020/3/7 12:55
**/
private static Color getRandomColor(){
Random ran = new Random();
Color color = new Color(ran.nextInt(256),
ran.nextInt(256),ran.nextInt(256));
return color;
}
}

二、调用验证码工具类的方法

/**
* description: 获取验证码图片
* param [response, request]
* author yuzonghao
* createTime 2020/3/7 13:36
**/
@GetMapping("/getCheckCode")
public void getCheckCode(HttpServletResponse response, HttpServletRequest request){
try {
int width=200;
int height=69;
BufferedImage verifyImg=new BufferedImage(width,height,BufferedImage.TYPE_INT_RGB);
//生成对应宽高的初始图片
String randomText = VerifyCodeUtil.drawRandomText(width,height,verifyImg);
request.getSession().setAttribute("verifyCode", randomText);
response.setContentType("image/png");//必须设置响应内容类型为图片，否则前台不识别
OutputStream os = response.getOutputStream(); //获取文件输出流
ImageIO.write(verifyImg,"png",os);//输出图片流
os.flush();
os.close();//关闭流
} catch (IOException e) {
log.error("获取验证码图片失败!",e);
}

三、生成效果：