jsp2.0表达式问题
相同的一个jsp文件，含有表达式的计算，为什么放在tomcat目录下的webapps目录下的任意应用程序目录下执行都可以得到正确的结果，如果应用程序目录不在tomcat目下的webapps下，执行就不会计算表达式，代码如下：
<!--
Copyright 2004 The Apache Software Foundation
Licensed under the Apache License, Version 2.0 (the "License ");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS " BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
-->
<html>
<head>
<title> JSP 2.0 Expression Language - Basic Arithmetic </title>
</head>
<body>
<h1> JSP 2.0 Expression Language - Basic Arithmetic </h1>
<hr>
This example illustrates basic Expression Language arithmetic.
Addition (+), subtraction (-), multiplication (*), division (/ or div),
and modulus (% or mod) are all supported. Error conditions, like
division by zero, are handled gracefully.
<br>
<blockquote>
<code>
<table border= "1 ">
<thead>
<td> <b> EL Expression </b> </td>
<td> <b> Result </b> </td>
</thead>
<tr>
<td> \${1} </td>
<td> ${1} </td>
</tr>
<tr>
<td> \${1 + 2} </td>
<td> ${1 + 2} </td>
</tr>
<tr>
<td> \${1.2 + 2.3} </td>
<td> ${1.2 + 2.3} </td>
</tr>
<tr>
<td> \${1.2E4 + 1.4} </td>
<td> ${1.2E4 + 1.4} </td>
</tr>
<tr>
<td> \${-4 - 2} </td>
<td> ${-4 - 2} </td>
</tr>
<tr>
<td> \${21 * 2} </td>
<td> ${21 * 2} </td>
</tr>
<tr>
<td> \${3/4} </td>
<td> ${3/4} </td>
</tr>
<tr>
<td> \${3 div 4} </td>
<td> ${3 div 4} </td>
</tr>
<tr>
<td> \${3/0} </td>
<td> ${3/0} </td>
</tr>
<tr>
<td> \${10%4} </td>
<td> ${10%4} </td>
</tr>
<tr>
<td> \${10 mod 4} </td>
<td> ${10 mod 4} </td>
</tr>
<tr>
<td> \${(1==2) ? 3 : 4} </td>
<td> ${(1==2) ? 3 : 4} </td>
</tr>
</table>
</code>
</blockquote>
</body>
</html>
附：我的tomcat版本是5.5的，我通过修改conf文件的server.xml方式配置了一个新的应用程序，只是该应用程序的目录不在tomcat目下的webapps下,我试过的，执行不含表达式的jsp页面没有问题的
[解决办法]
加上这句看看,
<% page isELIgnored= "false "%>