我要评论工具类：
package com.example.demo.util;
import lombok.extern.slf4j.slf4j;
import javax.imageio.imageio;
import java.awt.*;
import java.awt.image.bufferedimage;
import java.io.file;
import java.io.ioexception;
import java.security.securerandom;
/**
* 验证码工具类
*
* @author wangbo
* @since 2024/10/29
*/
@slf4j
public class captchageneratorutil {
private captchageneratorutil() {
// ...
}
public static void main(string[] args) throws ioexception {
// 生成4位随机数字验证码
string text = generaterandomcode();
// 创建验证码图片
bufferedimage image = createimage(text);
// 保存图片到文件
imageio.write(image, "png", new file("captcha.png"));
}
private static final securerandom random = new securerandom();
/**
* 生成4位随机数字字母验证码
*/
public static string generaterandomcode() {
stringbuilder code = new stringbuilder();
for (int i = 0; i < 4; i++) {
int i1 = random.nextint(3);
if (i1 == 0) {
code.append((char) (random.nextint(26) + 65));
} else if (i1 == 1) {
code.append((char) (random.nextint(26) + 97));
} else {
code.append(random.nextint(10));
}
}
log.info("生成的验证码文本 text = {}", code);
return code.tostring();
}
/**
* 创建验证码图片
*/
public static bufferedimage createimage(string text) {
log.info("待生成验证码图片的文本 text = {}", text);
int width = 75;
int height = 25;
bufferedimage image = new bufferedimage(width, height, bufferedimage.type_int_rgb);
// 使用graphics2d以获得更好的图形控制
graphics2d g2d = image.creategraphics();
try {
// 设置背景颜色
g2d.setcolor(new color(0xdcdcdc));
g2d.fillrect(0, 0, width, height);
// 设置字体和颜色
g2d.setfont(new font("arial", font.bold, 20));
g2d.setcolor(new color(0x004000));
// 确保文本不会超出图像边界
fontmetrics fm = g2d.getfontmetrics();
int textwidth = fm.stringwidth(text);
// 居中文本
int x = (width - textwidth) / 2;
// 居中文本（基线对齐）
int y = (height - fm.getheight()) / 2 + fm.getascent();
g2d.drawstring(text, x, y);
// 添加噪声线
for (int i = 0; i < 5; i++) {
g2d.setcolor(new color(random.nextint(255), random.nextint(255), random.nextint(255)));
g2d.drawline(random.nextint(width), random.nextint(height), random.nextint(width), random.nextint(height));
}
// 设置渲染提示以提高图像质量（可选）
g2d.setrenderinghint(renderinghints.key_antialiasing, renderinghints.value_antialias_on);
} finally {
// 确保在try块之后释放graphics2d资源
g2d.dispose();
}
return image;
}
private static final string captcha_prefix = "captcha:";
public static string generatecaptcharediskey(string key) {
return captcha_prefix + key;
}
}
生成图片验证码接口（该接口无需权限校验）：
/**
* 生成图片验证码
*
* @param key uuid字符串
*/
@getmapping("/captcha/generator/{key}")
public void captchagenerator(@pathvariable("key") string key, httpservletresponse response) throws baseexception {
userservice.captchagenerator(key, response);
}
public void captchagenerator(string key, httpservletresponse response) throws baseexception {
//查看key的验证码是否已存在
string captcharediskey = captchageneratorutil.generatecaptcharediskey(key);
boolean haskey = boolean.true.equals(redistemplate.haskey(captcharediskey));
if (haskey) {
throw new baseexception(errorcode.user_key_repetition);
}
string captcha = captchageneratorutil.generaterandomcode();
bufferedimage image = captchageneratorutil.createimage(captcha);
//设置验证码，有效期1分钟
redistemplate.opsforvalue().set(captcharediskey, captcha, 60l, timeunit.seconds);
response.setcontenttype("image/jpeg");
try (servletoutputstream out = response.getoutputstream()) {
imageio.write(image, "jpeg", out);
} catch (ioexception e) {
throw new runtimeexception(e);
}
}
登录接口或者其他涉及验证码的接口进行验证码校验：
//校验验证码
string key = loginpage.getkey();
string captcha = loginpage.getcaptcha();
if (stringutils.isnullorempty(key) || stringutils.isnullorempty(captcha)) {
throw new baseexception(errorcode.user_key_or_captcha_not_found);
}
string captcharediskey = captchageneratorutil.generatecaptcharediskey(key);
string rediscaptcha = redistemplate.opsforvalue().get(captcharediskey);
if (stringutils.isnullorempty(rediscaptcha) || !captcha.equalsignorecase(rediscaptcha)) {
throw new baseexception(errorcode.user_captcha_error);
} else {
//删除验证码缓存
redistemplate.delete(captcharediskey);
}
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