Java正则表达式匹配基本多语言平面外的字符

要删除所有非BMP字符,应执行以下操作:

String sanitizedString = inputString.replaceAll("[^\u0000-\uFFFF]", "");

您要查找特定字符还是BMP之外的所有字符?

StringBuilder 要从较高的平面构造包含代码点的字符串,regex将按预期工作:

  String test = new StringBuilder().append("test").appendCodePoint(0x10300).append("test").toString();
  Pattern regex = Pattern.compile(new StringBuilder().appendCodePoint(0x10300).toString());

  Matcher matcher = regex.matcher(test);
  matcher.find();
  System.out.println(matcher.start());

如果你想移除 字符串中的非BMP字符,然后我将使用 字符串拼接

  StringBuilder sb = new StringBuilder(test.length());
  for (int ii = 0 ; ii < test.length() ; )
  {
     int codePoint = test.codePointAt(ii);
     if (codePoint > 0xFFFF)
     {
        ii += Character.charCount(codePoint);
     }
     else
     {
        sb.appendCodePoint(codePoint);
        ii++;
     }
  }