JSP中使用EL表达式 ieELIgnoed问题

来源：未知责任编辑：责任编辑发表时间:2015-03-01 01:35　点击:次

在JSP中使用EL表达式时，需要标识 isELIgnored="false"，不然EL表达式是作为普通的字符串来编译的，而在页面上也不会显示出正确的值。

[html]

<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8" isELIgnored="false"%>

<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>

<c:out value="${param.para1}" default="hello world">

在apache-tomcat-6.0.35-src中可以看到这一点：

[java]

protected String[] generateJava() throws Exception {

String[] smapStr = null;

long t1, t2, t3, t4;

t1 = t2 = t3 = t4 = 0;

if (log.isDebugEnabled()) {

t1 = System.currentTimeMillis();

}

// Setup page info area

pageInfo = new PageInfo(new BeanRepository(ctxt.getClassLoader(),

errDispatcher), ctxt.getJspFile());

JspConfig jspConfig = options.getJspConfig();

JspConfig.JspProperty jspProperty = jspConfig.findJspProperty(ctxt

.getJspFile());

* If the current uri is matched by a pattern specified in a

* jsp-property-group in web.xml, initialize pageInfo with those

* properties.

if (jspProperty.isELIgnored() != null) {

pageInfo.setELIgnored(JspUtil.booleanValue(jspProperty

.isELIgnored()));

}