regex替换所有忽略的情况

Question

在下面的例子中，我如何忽略大小写？

outText = inText.replaceAll(word, word.replaceAll(" ", "~"));

示例：

输入：

inText = "Retail banking Wikipedia, the free encyclopedia Retail banking "
       + "From Wikipedia. retail banking industry."

word   = "retail banking"

输出

outText = "Retail~banking Wikipedia, the free encyclopedia Retail~banking " +
          "From Wikipedia. retail~banking industry."

Answer 1

若要执行不区分大小写的搜索和替换，可以更改

outText = inText.replaceAll(word, word.replaceAll(" ", "~"));

转到

outText = inText.replaceAll("(?i)" + word, word.replaceAll(" ", "~"));

避免破坏原来的大写：

然而，在上面的方法中，您正在破坏替换单词的大写。以下是一个更好的建议：

String inText="Sony Ericsson is a leading company in mobile. " +
              "The company sony ericsson was found in oct 2001";
String word = "sony ericsson";

Pattern p = Pattern.compile(word, Pattern.CASE_INSENSITIVE);
Matcher m = p.matcher(inText);

StringBuffer sb = new StringBuffer();

while (m.find()) {
  String replacement = m.group().replace(' ', '~');
  m.appendReplacement(sb, Matcher.quoteReplacement(replacement));
}
m.appendTail(sb);

String outText = sb.toString();

System.out.println(outText);

输出：

Sony~Ericsson is a leading company in mobile.
The company sony~ericsson was found in oct 2001

Answer 2

在进行搜索之前，您可以将其全部转换为小写，或者查看正则表达式修饰符Pattern.CASE_INSENSITIVE。

Answer 3

以下是我的做法：

        private String replaceAllIgnoreCase(final String text, final String search, final String replacement){
        if(search.equals(replacement)) return text;
        final StringBuffer buffer = new StringBuffer(text);
        final String lowerSearch = search.toLowerCase(Locale.CANADA);
        int i = 0;
        int prev = 0;
        while((i = buffer.toString().toLowerCase(Locale.CANADA).indexOf(lowerSearch, prev)) > -1){
            buffer.replace(i, i+search.length(), replacement);
            prev = i+replacement.length();
        }
        return buffer.toString();
    }

在我看来是完美无缺的。用我的方式来做它的好处是，在我的解决方案中没有正则表达式，这意味着如果您想替换一个括号或加号(或任何其他元字符)，它实际上将取代它的实际内容，而不是它在regex中的含义。希望这能帮上忙。