SimpleCaptcha is a simple Java library which can be used to develop random "captcha" generation for verification and validation purposes. Captcha is combination of background , text and line(noise) like below:
I used Spring boot to develop; this application is complete CRUD in which I did all necessary operation of user. User can register with verification and edit with verification and deleted also. Application allows to view all registered users also. Here is my git, you can download complete code.