google captcha验证码生成工具使用教程 样式配置

Posted 2022-12-08 一只猪的思考

1、引入依赖

<dependency>
			<groupId>com.github.penggle</groupId>
			<artifactId>kaptcha</artifactId>
			<version>2.3.2</version>
</dependency>

2、代码解析

通过源码分析可知，captcha主要是由Producer接口创建而成

而DefaultKaptcha又实现了Producer接口

所以我们只需要创建DefaultKaptcha对象即可生成验证码

通过Configurable源码又可得知这是配置验证码的父类
于是我们可以通过查阅官网资料配置properties
再通过Configurable继承的父类setConfig方法设置验证码样式即可
官网配置方法写在了最后面
下面是操作代码，大家可以结合理解

package com.liu.community.config;

import com.google.code.kaptcha.Producer;
import com.google.code.kaptcha.impl.DefaultKaptcha;
import com.google.code.kaptcha.util.Config;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import java.io.IOException;
import java.io.InputStream;
import java.util.Properties;

@Configuration
public class CaptchaConfiguration

    @Bean
    public Producer captchaProducer()
        Properties properties = new Properties();
        DefaultKaptcha kaptcha =null;
        InputStream in = CaptchaConfiguration.class.getClassLoader().getResourceAsStream("captcha.properties");
        try 
            properties.load(in);
            kaptcha = new DefaultKaptcha();
            kaptcha.setConfig(new Config(properties));
         catch (IOException e) 
            e.printStackTrace();
        

        return kaptcha;
    

@RequestMapping(path = "/captcha",method = RequestMethod.GET)
    public void generateCaptcha(HttpServletResponse response,HttpSession session)
        Producer producer = captchaConfiguration.captchaProducer();

//        生成验证码
        String text = producer.createText();
//        根据验证码生成图片
        BufferedImage image = producer.createImage(text);
//        存储验证码，登陆时检验
        session.setAttribute("captcha",text);
//        生成的是png格式
        response.setContentType("image/png");
        try 
            ServletOutputStream outputStream = response.getOutputStream();
//            传输图片
            ImageIO.write(image,"png",outputStream);
         catch (IOException e) 
            logger.error("响应验证码失败:" + e.getMessage());
        


    

配置文件

 kaptcha.image.width = 100
kaptcha.image.height = 40
kaptcha.textproducer.char.string = 123456789abcdefghijklmnopqrstuvwxiABCDEFGHIJKLMNOPQRSTUVWXI
kaptcha.textproducer.char.length = 4
kaptcha.textproducer.font.size = 30
kaptcha.textproducer.font.color = black

3、编写配置类

常量	描述	默认
kaptcha.border	Border around kaptcha. Legal values are yes or no.	yes
kaptcha.border.color	Color of the border. Legal values are r,g,b (and optional alpha) or white,black,blue.	black
kaptcha.border.thickness	Thickness of the border around kaptcha. Legal values are > 0.	1
kaptcha.image.width	Width in pixels of the kaptcha image.	200
kaptcha.image.height	Height in pixels of the kaptcha image.	50
kaptcha.producer.impl	The image producer.	com.google.code.kaptcha.impl.DefaultKaptcha
kaptcha.textproducer.impl	The text producer.	com.google.code.kaptcha.text.impl.DefaultTextCreator
kaptcha.textproducer.char.string	The characters that will create the kaptcha.	abcde2345678gfynmnpwx
kaptcha.textproducer.char.length	The number of characters to display.	5
kaptcha.textproducer.font.names	A list of comma separated font names.	Arial, Courier
kaptcha.textproducer.font.size	The size of the font to use.	40px.
kaptcha.textproducer.font.color	The color to use for the font. Legal values are r,g,b.	black
kaptcha.textproducer.char.space	The space between the characters	2
kaptcha.noise.impl	The noise producer.	com.google.code.kaptcha.impl.DefaultNoise
kaptcha.noise.color	The noise color. Legal values are r,g,b.	black
kaptcha.obscurificator.impl	The obscurificator implementation.	com.google.code.kaptcha.impl.WaterRipple
kaptcha.background.impl	The background implementation.	com.google.code.kaptcha.impl.DefaultBackground
kaptcha.background.clear.from	Starting background color. Legal values are r,g,b.	light grey
kaptcha.background.clear.to	Ending background color. Legal values are r,g,b.	white
kaptcha.word.impl	The word renderer implementation.	com.google.code.kaptcha.text.impl.DefaultWordRenderer
kaptcha.session.key	The value for the kaptcha is generated and is put into the HttpSession. This is the key value for that item in the session.	KAPTCHA_SESSION_KEY
kaptcha.session.date	The date the kaptcha is generated is put into the HttpSession. This is the key value for that item in the session.	KAPTCHA_SESSION_DATE