JSF 1.1和JSF 1.2 在支持EL能力上的差别

根据规范:

jsf 1.1

Value Binding Expression Syntax
The syntax of a value binding expression is identical to the syntax of an expression
language expression defined in the JavaServer Pages Specification (version 2.0),
sections 2.3 through 2.9, with the following exceptions:

1. 
   The expression delimiters for a value binding expression are “#{“ and “}” instead
   
2. 
   Value binding expressions do not support EL functions.

jsf 1.2

provided by version 2.1 of the JavaServer Pages specification. The EL is described in a
separate specification document delivered as part of the JSP 2.1 spec. Please consult that
document for complete details about the EL.

JSF 1.2中, JSP 1.2和JSP 2.1在EL 引擎上完全统一了，不像以前JSP和JSF是各自的EL引擎。

JSF 1.1中不支持 自定义EL function 的能力。所以必须通过其他技术手段来完成。