JSP由浅入深(8)―― JSP Tags_MySQL-Mysql Tutorial-php.cn

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JSP由浅入深(8)―― JSP Tags_MySQL

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Jun 01, 2016 pm 02:08 PM

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JSP另外一个重要的语法是Tags（标记）。JSP Tags不是使用字符里面。结束的标志是在字符

body

如果标志不需要一个主体，那么开始和结束标志可以合成在一起，比如：

这里我们利用一个/>替代了>字符，这样我们就可以快速地结束标志而不需要一个实体。这条语法跟XML的是一样的。

标志可以分成两种类型：一种是从外部标志库中转载的，另外一种是预先定义的标志。预先定义的标志是以jsp:字符开始的。举个例子吧，jsp:include是一个预先定义的标志，它用于包括其它的网页。

在前面的教程我们已经学习了“include directive”。其实它跟jsp:include是很相似的。它们都不是在原始文件中装载被包含的文件的文本，而是在运行的时候调用被包括的标志。下面是一个jsp:include 使用的例子：

Going to include hello.jsp...

现在将上面代码中的“jsp:include”改为“jsp:forward”看看它们有什么区别。其实这两个预先定义的标志是很有用的。

再给出本节的练习吧，编写一个JSP，使之根据一个布尔型（boolean）变量来对一个包含的文件。这里还是提示一下吧，要用到HTML和scriptlets的混合编程来处理JSP标志。

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