Verification code

Login assistance authentication is a common but necessary feature used by most systems. There are a variety of verification methods, such as graphic verification, verification bar, dragging puzzle pieces, etc. Here is a graphic verification code for the way to achieve. The open source implementation of KapCHA is adopted.

Introduction of kaptcha

Kaptcha is a highly configurable utility captcha generator with optional options such as:

• The font of the verification code
• The size of the captcha font
• The font color of the verification code font
• Verification code content range (numbers, letters, Chinese characters!)
• Captcha image size, border, border thickness, border color
• Verification code interference line
• Captcha styles (Fisheye style, 3D, plain blur,…)

Kaptcha configuration

Constant	describe	The default value
kaptcha.border	Image border, valid value: yes, no	yes
kaptcha.border.color	Border color, legal values: R, G, B (and optional alpha) or White,black,blue	black
kaptcha.image.width	Image width	200
kaptcha.image.height	Pictures of high	50
kaptcha.producer.impl	Picture implementation class	com.google.code.kaptcha.impl.DefaultKaptcha
kaptcha.textproducer.impl	Text implementation class	com.google.code.kaptcha.text.impl.DefaultTextCreator
kaptcha.textproducer.char.string	Text collection from which the captcha value is obtained	abcde2345678gfynmnpwx
kaptcha.textproducer.char.length	Verification code length	5
kaptcha.textproducer.font.names	The font	Arial, Courier
kaptcha.textproducer.font.size	The font size	40px.
kaptcha.textproducer.font.color	Font color, legal values: R, G, B or white,black,blue.	black
kaptcha.textproducer.char.space	Text interval	2
kaptcha.noise.impl	Interference implementation class	com.google.code.kaptcha.impl.DefaultNoise
kaptcha.noise.colorv	Interference colors, legal values: R, G, B or white,black,blue.	black
kaptcha.obscurificator.impl	Image style: Water lines com. Google. Code. Kaptcha. Impl. WaterRipple Fisheye com. Google. Code. Kaptcha. Impl. FishEyeGimpy Shadow com. Google. Code. Kaptcha. Impl. ShadowGimpy	com.google.code.kaptcha.impl.WaterRipple
kaptcha.background.impl	Background implementation class	com.google.code.kaptcha.impl.DefaultBackground
kaptcha.background.clear.from	Background color gradient, start color	light grey
kaptcha.background.clear.to	Background color gradient, end color	white
kaptcha.word.impl	Text renderer	com.google.code.kaptcha.text.impl.DefaultWordRenderer
kaptcha.session.key	session key	KAPTCHA_SESSION_KEY
kaptcha.session.date	session date	KAPTCHA_SESSION_DATE

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Implementation captcha

Introduce kaptCHA dependencies

        <! Add captcha implementation library dependency kaptcha-->
        <dependency>
            <groupId>com.github.axet</groupId>
            <artifactId>kaptcha</artifactId>
            <version>0.0.9</version>
 </dependency> Copy the code

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Adding a Configuration Class

/ * ** Captcha configuration class* /
@Configuration
public class KaptchaConfig {
  @Bean  public DefaultKaptcha producer(a) throws KrbException {  Properties properties = new Properties();  properties.put("kaptcha.border"."no");  properties.put("kaptcha.textproducer.font,color"."black");  properties.put("kaptcha.textproducer.char.space"."5");  Config config = new Config(properties);  DefaultKaptcha defaultKaptcha = new DefaultKaptcha();  defaultKaptcha.setConfig(config);  return defaultKaptcha;  } } Copy the code

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Interface implementation

@Api(tags = "Login Verification")
@RequestMapping(value = "login")
@RestController
public class SysLoginController {

 @Autowired  private Producer producer;   @ApiOperation(value = "Generate captcha image")  @GetMapping(value = "captchat.jpg")  public void createKacptcha(HttpServletResponse response, HttpServletRequest request) throws IOException {  response.setHeader("Cache-Control"."no-store");  response.setContentType("image/jpeg");  // Text verification code  String text = producer.createText();  // Image verification code  BufferedImage image = producer.createImage(text);  // Save the verification code to session  request.getSession().setAttribute(Constants.KAPTCHA_SESSION_KEY,text);  ServletOutputStream outputStream = response.getOutputStream();  ImageIO.write(image,"jpg",outputStream);  IOUtils.closeQuietly(outputStream);  } } Copy the code

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test

Open the Swagger interface test page and execute the interface. The result is as follows. Each time it is executed, the verification code is refreshed

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