正则表达式从下面的页面中提取段落

Question

我有使用iText从pdf中提取的文本，并将其放入String变量中：

(1) A a, — al'-fah; of Hebrew origin; the first letter of the alphabet;
figurative only (from its use as a numeral) the first: — Alpha.
Often used (usually ajn an, before a vowel) also in composition
(as a contraction from (427) (a]neu,)) in the sense of privation;
so in many words beginning with this letter; occasionally in the
sense of union (as a contraction of (260) (a[ma)).
(2) ÆAarw>n, — ah-ar-ohn'; of Hebrew origin [Hebrew {175}
('Aharown)]; Aaron, the brother of Moses: — Aaron.
(3) ÆAbaddw>n, — ab-ad-dohn'; of Hebrew origin [Hebrew {11}
('abaddown)]; a destroying angel: — Abaddon.
(4) ajbarh>v, — ab-ar-ace'; from (1) (a) (as a negative particle) and (922)
(ba>rov); weightless, i.e. (figurative) not burdensome: — from
being burdensome.
(5) ÆAbba~, — ab-bah'; of Chaldee origin [Hebrew {2} ('ab (Chaldee))];
father (as a vocative): — Abba.
(6) &Abel, — ab'-el; of Hebrew origin [Hebrew {1893} (Hebel)]; Abel,
the son of Adam: — Abel.
(7) ÆAbia>, — ab-ee-ah'; of Hebrew origin [Hebrew {29} ('Abiyah)];
Abijah, the name of two Israelites: — Abia.
(8) ÆAbia>qar, — ab-ee-ath'-ar; of Hebrew origin [Hebrew {54}
('Ebyathar)]; Abiathar, an Israelite: — Abiathar.
(9) ÆAbilhnh>, — ab-ee-lay-nay'; of foreign origin [compare Hebrew {58}
('abel)]; Abilene, a region of Syria: — Abilene.
(10) ÆAbiou>d, — ab-ee-ood'; of Hebrew origin [Hebrew {31}
('Abiyhuwd)]; Abihud, an Israelite: — Abiud.

字符串中的段落以(9)或(5) ([0-9])开头，我想使用pagestring.split("regex")提取以该字符序列开头的每个段落。 可以帮忙吗？

Answer 1

这样可以避免在文本中嵌入的“（999）”上产生分裂。 它基于以下假设：行尾在括号内的数字之前，该数字指示段落的开头。 另请注意，示例文本会在第一个带括号的数字之前的任何文本中生成一个空的“段落”，因此为if语句。

  String text = ...;
  String[] paras = text.split( "(?<=(^|\\n))\\(\\d+\\)" );
  for( String para: paras ){
      if( para.length() > 0 ){
          System.out.println( "Para: " + para );
      }
  }

Answer 2

您可以将以下正则表达式"[\\n|.]\\\\([0-9]{1,2}\\\\)"与split方法一起使用，它将从文本中提取所有段落（包括从0到0的数字） 99）：

String[] parts=st.split("[\n|.]\\([0-9]{1,2}\\)");

[\\n|.] ：仅考虑新段落，而忽略段落文本中的(n) 。

\\\\([0-9]{1,2}\\\\) ：匹配（）中的任何一组一 两位数字。

这是有效的DEMO ，给出了一个包含所有段落的数组。

有关使用正则表达式的更多信息，请参见Java Regex Pattern 。