您的web.xml可能引用了Servlet 2.3规范，其中 isELIgnored 设置为 true 默认情况下。如果您引用Servlet 2.4规范，默认情况下 isELIgnored 将设置为 false 。

Your web.xml is probably referencing the Servlet 2.3 spec, in which isELIgnored is set to true by default. If you reference the Servlet 2.4 spec instead, isELIgnored will be set to false by default.

如果你想引用Servlet 2.4规范，你的web.xml标题应如下所示：

If you want to reference the Servlet 2.4 spec, your web.xml header should look something like this:

<web-app xmlns="http://java.sun.com/xml/ns/j2ee"
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd"
     version="2.4">