Bundled Tomcat can be setup to support 1.5 features in JSPs. IDE could do it
automatically when user sets 1.5 Source level of WebApp. Although Tomcat using
non-jasper parser (default Tomcat configuration) doesn't have this possibility.

Notice: Running Bundled Tomcat on 1.4.x JDK with source level set to 1.5 (see
bellow) will fail all JSP compilations.

Modify TOMCAT_BASE/conf/web.xml
  <servlet>
    <servlet-name>jsp</servlet-name>
    <servlet-class>org.apache.jasper.servlet.JspServlet</servlet-class>
    <init-param>
      <param-name>fork</param-name>
      <param-value>false</param-value>
    </init-param>
    <init-param>
      <param-name>xpoweredBy</param-name>
      <param-value>false</param-value>
    </init-param>
+    <init-param>
+      <param-name>compilerSourceVM</param-name>
+      <param-value>1.5</param-value>
+    </init-param>
+    <init-param>
+      <param-name>compilerTargetVM</param-name>
+      <param-value>1.5</param-value>
+    </init-param>
    <init-param>
      <param-name>mappedfile</param-name>
      <param-value>true</param-value>
    </init-param>
    <load-on-startup>3</load-on-startup>
  </servlet>

Based on nbusers thread:
http://www.netbeans.org/servlets/ReadMsg?list=nbusers&msgNo=53786