Freemaker Replace函数的正则表达式运用

replace(param1,param2,param3)

param1 正则表达式；param2 将匹配的字符替换成指定字符；param3 模式

param3 参数如下

模式	i	r	m	s	c	f
replace	支持	支持	只和r 组合	只和r 组合	只和r 组合	支持

模式解释：

i: Case insensitive: 忽略大小写

f: First only. That is, replace/find/etc. only the first occurrence of something.

r: The substring to find is a regular expression.标准正则表达式（http://docs.oracle.com/javase/7/docs/api/java/util/regex/Pattern.html ）

m: Multi-line mode for regular expressions. In multi-line mode the expressions ^ and $ match just after or just before, respectively, a line terminator or the end of the string. By default these expressions only match at the beginning and the end of the entire string. Note that ^ and $ doesn't match the line-break character itself.

s: Enables dot-all mode for regular expressions (same as Perl singe-line mode). In dot-all mode, the expression . matches any character, including a line terminator. By default this expression does not match line terminators.

c: Permits whitespace and comments in regular expressions.在正则表达式中允许空格和注释。

范例如下：

<#assign s = 'foo bAr baar'>
${s?replace('ba', 'XY')}
i: ${s?replace('ba', 'XY', 'i')}
if: ${s?replace('ba', 'XY', 'if')}
r: ${s?replace('ba*', 'XY', 'r')}
ri: ${s?replace('ba*', 'XY', 'ri')}
rif: ${s?replace('ba*', 'XY', 'rif')}  

输出结果：

foo bAr XYar
i: foo XYr XYar
if: foo XYr baar
r: foo XYAr XYr
ri: foo XYr XYr
rif: foo XYr baar 

更多范例：

原文：str = 2积分兑换30元优惠券
${str?replace('\b\d+积分','','r')} 
输出：兑换30元优惠券

更多信息可以参考：

http://freemarker.org/docs/ref_builtins_string.html#ref_builtin_replace