java - 需要正则表达式来删除多个换行符之间的空格

Question

我正在处理一些 rawString，其中我需要从某些地方删除\n，而有些地方如果显示\n，我需要进入下一行。例如输入:-

 ** As the coronavirus impact weighs, LMT to advance more\nthan $50 mln to small, medium-sized business partners in its\nsupply chain to protect jobs, support economy \n  \n  *New line should start\n\nregular \n  \n \n  \n text.

I am getting the result Partially using this code

 String str = input.replaceAll("\\n","~").replaceAll("~\\s+",System.lineSeparator()+System.lineSeparator()).replaceAll("~", " ");

现在我得到的结果:

** As the coronavirus impact weighs, LMT to advance more than $50 mln to small, medium-sized business partners in its supply chain to protect jobs, support economy*New line should startregular text.

但问题是我连续得到不止一次“\n”，所有\n都替换为一个“\n”，因为此时我得到的“\n”带有空格，它会转到下一个行，例如，因此它就像“\n\n 关键字”，在这种情况下，“关键字”显示在正确的下一行中，但在该行上方创建一个额外的行会出现问题。任何人都可以帮忙解决这个问题吗？

预期:-

** As the coronavirus impact weighs, LMT to advance more than $50 mln to small, medium-sized business partners in its supply chain to protect jobs, support economy*New line should startregular text.

换行输入模式

\n\n\n SomeText、\n\n SomeText\n、\n\n\n SomeText

在上述所有模式中，someText 将从下一行开始。

图案只会创造空间

\nSomeText、\n\n\nSomeText\n\n、\nSomeText

在所有这些情况下都只会创建空间 "",

Answer 1

我建议进行以下更新:

String str = input
    .replaceAll("(\\n\\s+){2,}","~") // find duplicate linefeeds with optional spaces
    .replaceAll("\\n"," ") // replace remaining linefeeds with spaces
    .replaceAll("\\s{3,}", "") // remove redundant spaces
    .replaceAll("\\s{2}", " ") // replace duplicate spaces with one
    .replaceAll("~", System.lineSeparator() + System.lineSeparator() // restore linefeeds
);

它产生以下文本:

** As the coronavirus impact weighs, LMT to advance more than $50 mln to small, medium-sized business partners in its supply chain to protect jobs, support economy 

*New line should start regular 

text.

新测试用例更新

String str = input
        .replaceAll("(\\n +\\n| \\n+ )","~") // mark duplicate linefeeds with optional spaces
        .replaceAll("\\n+"," ") // replace remaining linefeeds with spaces
        .replaceAll("(~\\s*)+","~") // remove duplicate linefeed marks with optional spaces
        .replaceAll("\\s{3,}", "") // remove redundant spaces
        .replaceAll("\\s{2}", " ") // replace duplicate spaces
        .replaceAll("~", System.lineSeparator() + System.lineSeparator()) // restore linefeeds
    ;
    System.out.println("[" + str + "]");

情况 2:“\n\n\n SomeText1、\n\n SomeText2\n、\n\n\n SomeText3”

[\n
\n
SomeText1,\n
\n
SomeText2 ,\n
\n
SomeText3]

情况 3:“\nSomeText1、\n\n\nSomeText2\n\n、\nSomeText3”

[ SomeText1, SomeText2 , SomeText3]