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

ps：freemarker的replace功能

替换字符串 replace 

${s?replace(‘ba', ‘xy' )} 
${s?replace(‘ba', ‘xy' , ‘规则参数')}

将s里的所有的ba替换成xy 规则参数包含: i r m s c f 具体含义如下: 

· i: 大小写不区分. 
· f: 只替换第一个出现被替换字符串的字符串 
· r:  xy是正则表达式 

· 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. 

· s: enables dotall mode for regular expressions (same as perl singe-line mode). in dotall 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.