java - 如何使用java中的正则表达式提取下面文本中所需的字符串？

Question

我想提取下面文本中第一个和最后一个之间的字符串。

场景1:

"Select statement"+"\n"+
"first"+"\n"+
"I want to extract this" +"\n"+
"I want to extract this one too"+"\n"+
"last"+"\n"+
"end of the statement"+"\n"+
"first"+"\n"+
"I want to extract this" +"\n"+
"I want to extract this one too"+"\n"+
"last"+"\n"+
"end of the statement"

场景 2:

"Select statement"+"\n"+
"first"+"\n"+
"I want to extract this" +"\n"+
"last"+"\n"+
"end of the statement";

Java 中的正则表达式模式是什么来完成这项工作？模式应该是一种，但它应该在两种情况下都有效。感谢您的帮助。

Answer 1

您可以使用环视。

Matcher m = Pattern.compile("(?s)(?<=\\bfirst\\n).*?(?=\\n?\\blast\\b)").matcher(s);
if(m.find())
  {
      System.out.println(m.group());
  }