说明：  Web程序员能够利用 JSTL和 EL来开发 Web程序，取代传统直接在页面上 嵌入Java程序(Scripting)的做法，以提高程序的阅读性、维护性和方便性。
(Web programmers can use JSTL and EL to develop Web programs instead of traditional ones directly on the page. Embedding Java program (Scripting) to improve the readability, maintainability and convenience of the program.)