Java 正则表达式从复杂字符串中提取子字符串

我有一个字符串，可以有两种格式

第一种格式：

route-policy testPolicy
  if (destination in pfx_manju) then
    set extcommunity rt (10429:103) additive
  endif
end-policy

route-policy testPolicy
  if (destination in EXP1) then
    set extcommunity rt (27699:352002, 2.2.2.2:98) additive
  elseif (destination in pfx_manju) then
    set extcommunity rt (27699:339600, 27679:339700, 1.1.1.1:6763, 65536:45633) additive
  elseif (destination in EXP5) then
    drop
  endif
end-policy

route-policy EXPORTRP1
  if (destination in EXP1) or (destination in EXP2) then
    set extcommunity rt (27699:352002, 2.2.2.2:98) additive
  elseif (destination in pfx_manju) or (destination in EXP4) then
    set extcommunity rt (27699:339600, 27679:339700, 1.1.1.1:6763, 65536:45633) additive
  elseif (destination in EXP5) or (destination in EXP6) then
    drop
  endif
end-policy

  pfx_manju) then
    set extcommunity rt (10429:103) additive

pfx_manju) or (destination in EXP4) then
        set extcommunity rt (27699:339600, 27679:339700, 1.1.1.1:6763, 65536:45633) additive

第二种格式：

route-policy testPolicy
  if (destination in pfx_manju) then
    set extcommunity rt (10429:103) additive
  endif
end-policy

route-policy testPolicy
  if (destination in EXP1) then
    set extcommunity rt (27699:352002, 2.2.2.2:98) additive
  elseif (destination in pfx_manju) then
    set extcommunity rt (27699:339600, 27679:339700, 1.1.1.1:6763, 65536:45633) additive
  elseif (destination in EXP5) then
    drop
  endif
end-policy

route-policy EXPORTRP1
  if (destination in EXP1) or (destination in EXP2) then
    set extcommunity rt (27699:352002, 2.2.2.2:98) additive
  elseif (destination in pfx_manju) or (destination in EXP4) then
    set extcommunity rt (27699:339600, 27679:339700, 1.1.1.1:6763, 65536:45633) additive
  elseif (destination in EXP5) or (destination in EXP6) then
    drop
  endif
end-policy

  pfx_manju) then
    set extcommunity rt (10429:103) additive

pfx_manju) or (destination in EXP4) then
        set extcommunity rt (27699:339600, 27679:339700, 1.1.1.1:6763, 65536:45633) additive

第三种格式：

route-policy testPolicy
  if (destination in pfx_manju) then
    set extcommunity rt (10429:103) additive
  endif
end-policy

route-policy testPolicy
  if (destination in EXP1) then
    set extcommunity rt (27699:352002, 2.2.2.2:98) additive
  elseif (destination in pfx_manju) then
    set extcommunity rt (27699:339600, 27679:339700, 1.1.1.1:6763, 65536:45633) additive
  elseif (destination in EXP5) then
    drop
  endif
end-policy

route-policy EXPORTRP1
  if (destination in EXP1) or (destination in EXP2) then
    set extcommunity rt (27699:352002, 2.2.2.2:98) additive
  elseif (destination in pfx_manju) or (destination in EXP4) then
    set extcommunity rt (27699:339600, 27679:339700, 1.1.1.1:6763, 65536:45633) additive
  elseif (destination in EXP5) or (destination in EXP6) then
    drop
  endif
end-policy

  pfx_manju) then
    set extcommunity rt (10429:103) additive

pfx_manju) or (destination in EXP4) then
        set extcommunity rt (27699:339600, 27679:339700, 1.1.1.1:6763, 65536:45633) additive

所以这里完整的文本是字符串。字符串可以是单个条件（if）或多个条件（elseIf条件）

从上面的字符串中，我想提取一个硬编码策略（pfx_manju）的rt值。我可以用下面的正则表达式提取rt值

final String regex = "rt \\(([^)]+)\\)";

现在的问题是，我想提取属于硬编码策略（pfx_manju）的子字符串

因此，条件是获取一个子字符串，起始位置是索引pfx_manju，结束位置是后续的endif或elseif

所以我想要上面例子的sub-sting输出，如下所述

第一个子字符串：

route-policy testPolicy
  if (destination in pfx_manju) then
    set extcommunity rt (10429:103) additive
  endif
end-policy

route-policy testPolicy
  if (destination in EXP1) then
    set extcommunity rt (27699:352002, 2.2.2.2:98) additive
  elseif (destination in pfx_manju) then
    set extcommunity rt (27699:339600, 27679:339700, 1.1.1.1:6763, 65536:45633) additive
  elseif (destination in EXP5) then
    drop
  endif
end-policy

route-policy EXPORTRP1
  if (destination in EXP1) or (destination in EXP2) then
    set extcommunity rt (27699:352002, 2.2.2.2:98) additive
  elseif (destination in pfx_manju) or (destination in EXP4) then
    set extcommunity rt (27699:339600, 27679:339700, 1.1.1.1:6763, 65536:45633) additive
  elseif (destination in EXP5) or (destination in EXP6) then
    drop
  endif
end-policy

  pfx_manju) then
    set extcommunity rt (10429:103) additive

pfx_manju) or (destination in EXP4) then
        set extcommunity rt (27699:339600, 27679:339700, 1.1.1.1:6763, 65536:45633) additive

第二个子字符串：

pfx_manju) then
        set extcommunity rt (27699:339600, 27679:339700, 1.1.1.1:6763, 65536:45633) additive

第三个子字符串：

route-policy testPolicy
  if (destination in pfx_manju) then
    set extcommunity rt (10429:103) additive
  endif
end-policy

route-policy testPolicy
  if (destination in EXP1) then
    set extcommunity rt (27699:352002, 2.2.2.2:98) additive
  elseif (destination in pfx_manju) then
    set extcommunity rt (27699:339600, 27679:339700, 1.1.1.1:6763, 65536:45633) additive
  elseif (destination in EXP5) then
    drop
  endif
end-policy

route-policy EXPORTRP1
  if (destination in EXP1) or (destination in EXP2) then
    set extcommunity rt (27699:352002, 2.2.2.2:98) additive
  elseif (destination in pfx_manju) or (destination in EXP4) then
    set extcommunity rt (27699:339600, 27679:339700, 1.1.1.1:6763, 65536:45633) additive
  elseif (destination in EXP5) or (destination in EXP6) then
    drop
  endif
end-policy

  pfx_manju) then
    set extcommunity rt (10429:103) additive

pfx_manju) or (destination in EXP4) then
        set extcommunity rt (27699:339600, 27679:339700, 1.1.1.1:6763, 65536:45633) additive

---

任何带有乐观解决方案的建议都将不胜感激

以下正则表达式应该有效

pfx_manju\)[\s\S]*?rt \(([^)]+)\) additive

正则表达式匹配从

pfx_manju

条件开始一直到

rt

值的字符串，这意味着它在只有

pfx_manju

条件时捕获rt值。如果您使用的是java，则需要scape，

\

---

请参见regex

是您给定的子字符串，还是要提取的字符串？是。。我提到的字符串是我应该提取的Cary Swoveland，是的，字符串将始终包含一个带有“prx_manju”的条件，如果字符串不包含“prx_manju”，我将不在这里处理任何事情。好的，我猜字符串总是有条件

pfx_manju

，正如您所提到的那样。用所有可能的方法更新了问题，并添加了注释“是”，尝试了您的建议。感谢您的时间和投入