Simple verification code generation java version

We all know the verification code. I don't need to say more about its role. If it is not clear, please refer to the explanation in Baidu Encyclopedia. Generally, the generation of verification code is to randomly generate characters (numbers, letters or Chinese characters, etc.), then draw these generated characters into a picture, and then add some interference elements, such as various lines, to the picture. Well, no more nonsense. Let's look down together:

Simple login page (the code is not complete, only the verification code)

Through session Getattribute ("Rand"), get the generated verification code, compare it with the one entered by the user, and then handle it accordingly according to the comparison results.

Generate verification code through servlet:

web. Servlet configuration information in XML:

In this way, the function of the verification code is realized, which is very simple and practical. Of course, there are more beautiful and rigorous ways. Interested friends can study it in depth. Here is a simple way to share with you. You are welcome to criticize and correct.

The above is the whole content of this article. I hope it will be helpful to your study, and I hope you can support programming tips.