Java implements kaptcha web page verification code verification
First, let’s understand what verification code is:
- Verification Code (CAPTCHA): It is a public fully automatic program that distinguishes whether a user is a computer or a human.
- effect: It can prevent malicious password cracking, ticket swiping, and forum flooding, and effectively prevent a hacker from constantly logging in with a specific registered user using a specific program to brute-force cracking method. In fact, using verification codes is a common method for many websites now (such as China Merchants Bank’s online personal banking and Baidu Community). We have implemented this function in a relatively simple way.
Let's learn about kaptcha together
First of all, we need to understand what kaptcha is?
- It is a Java open source verification code toolkit, kaptcha is a very practical verification code generation tool that can generate diverse verification codes through configuration.
- Of course, in addition to kaptcha, verification code can also be implemented through servlets and jcaptcha.
How does kaptcha work:
- Call to generate an image.
- At the same time, put the generated verification code string into HttpSession.