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Today, I would like to share with you the relevant knowledge of how to write the script of JavaScript login CAPTCHA. The content is detailed and the logic is clear. I believe most people still know too much about this, so share this article for your reference. I hope you can get something after reading this article. Let's take a look at it.

Fill in the input information index.jsp

Generate picture image.jps

Get random colors in a given range

Fc = 255; if (bc > 255) bc = 255; int r = fc + random.nextInt (bc-fc); int g = fc + random.nextInt (bc-fc); int b = fc + random.nextInt (bc-fc); return new Color (r, g, b) }% > validation is a problem that you may encounter when entering the correct result.jsp:

Your eclipse will prompt you that there is something wrong with the graphic.drawString () method.

Your jdk version is too high, but it doesn't matter. It would be nice to lower the compatible version of the project.

Specific operation steps:

Right-click the process, select propriety, and then select "Java compiler"

Just reduce the compatible version of jdk to 1.4.

These are all the contents of the article "how to write the script for JavaScript login CAPTCHA". Thank you for reading! I believe you will gain a lot after reading this article. The editor will update different knowledge for you every day. If you want to learn more knowledge, please pay attention to the industry information channel.

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