JSP学习之四Q?/span>JSP指o
CoffeeTree 2009-1-5
一?/span>指o基础
a) 指o的格式:<%@ 指o?/span> [….一个或多个属?/span>….] %>Q?/span>
b) 指o的作用:告诉容器在解?/span>JSP时的一些约定;
c) 可用?/span>JSP指o
i. page指o;
ii. taglib指o
iii. include指o
d) JSP指o的处理(注意各个动作所发生的阶D)

二?/span>page指o
告诉容器译阶段如何处理JSP文g?/span>
1. language属?/span> Q?/span><%@ page language=”java” %> 此ؓ默认Q?/span>
2. extends属?/span> Q用超c,基本不用Q?/span>
3. import属?/span> Q?/span><%@ page import=”java.util.*” %> Q?/span>
4. session属?/span> Q?/span>true | false Q?/span>
5. info属?/span> Q指定页面信息,基本不用Q?/span>
6. isELIgnored属?/span> Q?/span>true | false Q?/span>
7. isErrorPage属?/span> Q?/span>true | false Q?/span>
8. errorPage属?/span> Q?/span><%@ page errorPage=”error.jsp” %> Q?/span>
9. contentType属?/span> Q?/span>text/html | text/xml Q?/span>
三?/span>taglib指o
taglib指o的工作流E在?/span> JSP学习之三Q?/span>EL & JSTL(?/span>) 》中已经描述Q关键字Q?/span>taglib映射Q?/span>TLD Q?/span>
1. uri属?/span>
taglib指o告诉容器?/span>JSP用与?/span>uri相关联的标记库?/span>
2. tagdir属?/span>
指定标记库具体目录。(必须?/span>/WEB-INF/tags目录或子目录下)
3. prefix属?/span>
指定一个前~?/span>
隐式包含介绍Q?/span>
如果你开发了一个项目,每一?/span>JSP都用C10个不同的标记库,在每?/span>JSP前面都指?/span>10?/span>taglib指o会很ȝQ此旉式包含可以方便的解决此问题,其处理方法类gC语言中引入一?/span>.h文g?/span>
WEB.xmldQ?/span>
<jsp-config>
<jsp-property-group>
<uri-pattern> index.jsp</uri-pattern>
<include-preclude> /WEB-INF/jspf/pre.jspf</include-preclude>
</jsp-property-group>
</jsp-config>
/WEB-INF/jspf/pre.jspfQ?/span>
<%@ taglib prefix=”c” uri=http://java.sun.com/jsp/jstl/core %>
<%@ taglib prefix=”fmt” uri=http://java.sun.com/jsp/jstl/format %>
四?/span>include指o
include指o告诉容器Q在译阶段把其他文件的内容与当?/span>JSP合ƈ?/span>
1Q?span style="font: 7pt 'Times New Roman'"> 所包含的所?/span>JSP代码都不会被执行Q甚至不会被~译?/span>
2Q?span style="font: 7pt 'Times New Roman'"> 首先合ƈ文gQ然后合q后的整个输ZZ个单元得到翻译?/span>
3Q?span style="font: 7pt 'Times New Roman'"> 如果所包含的文件有所改动Q容器没有一般的Ҏ来知道这一点,只能重新~译整个译单元?/span>
<jsp : include >动作?span style="color: red">h时发?/span>Q可以克服以上限制?br />



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