在工作中，我的任务是让一群人HTML文件变成一个简单的JSP项目。它实际上是静态的，没有服务器端的逻辑来编程。我应该指出，我对Java完全陌生。JSP文件似乎使处理公共包含和变量变得很容易，就像PHP，但是我想知道一个简单的方法来获得类似于模板继承的东西(Django样式)，或者至少能够有一个base.jsp文件，其中包含页眉和页脚，这样以后我就可以插入内容了。本灵他的回答似乎带来了一些希望：JSP模板继承有人能解释一下如何做到这一点吗？考虑到我没有太多的时间，我认为动态路由有点多，所以我很高兴让URL直接映射到.jsp文件，但我愿意接受建议。谢谢。编辑：我不想使用任何外部库，因为它会增加我自己和其他从事这个项目的人的学习曲线，而我工作的公司已经签约这样做了。另一个编辑：我不确定JSP tags将是有用的，因为我的内容实际上没有任何模板变量。我需要的是一种能够做到这一点的方法：base.html:<html><body>{ content.body }</body></html>somepage.html<wrapper:base.html><h1>Welcome</h1></wrapper>产出如下：<html><body><h1>Welcome</h1></body></html>我想这会给我足够多的能力去做我所需要的一切。它可以通过includes但是，我需要一个顶部和一个底部包含每个包装，这有点麻烦。使模板变得更容易的JSP技巧？
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翻阅古今
TA贡献1780条经验 获得超5个赞
<%--
The block tag implements a basic but useful extensible template system.
A base template consists of a block tag without a 'template' attribute.
The template body is specified in a standard jsp:body tag, which can
contain EL, JSTL tags, nested block tags and other custom tags, but
cannot contain scriptlets (scriptlets are allowed in the template file,
but only outside of the body and attribute tags). Templates can be
full-page templates, or smaller blocks of markup included within a page.
The template is customizable by referencing named attributes within
the body (via EL). Attribute values can then be set either as attributes
of the block tag element itself (convenient for short values), or by
using nested jsp:attribute elements (better for entire blocks of markup).
Rendering a template block or extending it in a child template is then
just a matter of invoking the block tag with the 'template' attribute set
to the desired template name, and overriding template-specific attributes
as necessary to customize it.
Attribute values set when rendering a tag override those set in the template
definition, which override those set in its parent template definition, etc.
The attributes that are set in the base template are thus effectively used
as defaults. Attributes that are not set anywhere are treated as empty.
Internally, attributes are passed from child to parent via request-scope
attributes, which are removed when rendering is complete.
Here's a contrived example:
====== WEB-INF/tags/block.tag (the template engine tag)
<the file you're looking at right now>
====== WEB-INF/templates/base.jsp (base template)
<%@ page trimDirectiveWhitespaces="true" %>
<%@ taglib prefix="t" tagdir="/WEB-INF/tags" %>
<t:block>
<jsp:attribute name="title">Template Page</jsp:attribute>
<jsp:attribute name="style">
.footer { font-size: smaller; color: #aaa; }
.content { margin: 2em; color: #009; }
${moreStyle}
</jsp:attribute>
<jsp:attribute name="footer">
<div class="footer">
Powered by the block tag </div>
</jsp:attribute>
<jsp:body>
<html>
<head>
<title>${title}</title>
<style>
${style}
</style>
</head>
<body>
<h1>${title}</h1>
<div class="content">
${content}
</div>
${footer}
</body>
</html>
</jsp:body>
</t:block>
====== WEB-INF/templates/history.jsp (child template)
<%@ page trimDirectiveWhitespaces="true" %>
<%@ taglib prefix="t" tagdir="/WEB-INF/tags" %>
<t:block template="base" title="History Lesson">
<jsp:attribute name="content" trim="false">
<p>${shooter} shot first!</p>
</jsp:attribute>
</t:block>
====== history-1977.jsp (a page using child template)
<%@ page trimDirectiveWhitespaces="true" %>
<%@ taglib prefix="t" tagdir="/WEB-INF/tags" %>
<t:block template="history" shooter="Han" />
====== history-1997.jsp (a page using child template)
<%@ page trimDirectiveWhitespaces="true" %>
<%@ taglib prefix="t" tagdir="/WEB-INF/tags" %>
<t:block template="history" title="Revised History Lesson">
<jsp:attribute name="moreStyle">.revised { font-style: italic; }</jsp:attribute>
<jsp:attribute name="shooter"><span class="revised">Greedo</span></jsp:attribute>
</t:block>--%><%@ tag trimDirectiveWhitespaces="true" %><%@ tag import="java.util.HashSet, java.util.Map, java.util.Map.Entry" %>
<%@ tag dynamic-attributes="dynattributes" %><%@ attribute name="template" %><%
// get template name (adding default .jsp extension if it does not contain
// any '.', and /WEB-INF/templates/ prefix if it does not start with a '/')
String template = (String)jspContext.getAttribute("template");
if (template != null) {
if (!template.contains("."))
template += ".jsp";
if (!template.startsWith("/"))
template = "/WEB-INF/templates/" + template;
}
// copy dynamic attributes into request scope so they can be accessed from included template page
// (child is processed before parent template, so only set previously undefined attributes)
Map<String, String> dynattributes = (Map<String, String>)jspContext.getAttribute("dynattributes");
HashSet<String> addedAttributes = new HashSet<String>();
for (Map.Entry<String, String> e : dynattributes.entrySet()) {
if (jspContext.getAttribute(e.getKey(), PageContext.REQUEST_SCOPE) == null) {
jspContext.setAttribute(e.getKey(), e.getValue(), PageContext.REQUEST_SCOPE);
addedAttributes.add(e.getKey());
}
}%><% if (template == null) { // this is the base template itself, so render it %>
<jsp:doBody/><% } else { // this is a page using the template, so include the template instead %>
<jsp:include page="<%= template %>" /><% } %><%
// clean up the added attributes to prevent side effect outside the current tag
for (String key : addedAttributes) {
jspContext.removeAttribute(key, PageContext.REQUEST_SCOPE);
}%>添加回答
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