我正在尝试仅从字符串的开头替换非alpanumeric字符。我想出了以下代码:
public static final class FixNonAlphaNumBegin implements PhraseFilter {
@Override
public String filter(String phrase, long frequency) {
int count = 0;
while (!Character.isLetterOrDigit(phrase.codePointAt(count))
&& phrase.length() > count + 1) {
phrase = phrase.replaceFirst(
Pattern.quote(phrase.substring(count, count + 1)), "");
count++;
}
return phrase.trim();
}
}
IndexOutOfBoundsException来自哪里?它应该是不可能的:
e.g。
String filter = "! "
!Character.isLettorDigit(phrase.codePointAt(0) --> true
phrase.length() > 1 --> true
phrase = phrase.replaceFirst(
Pattern.quote(phrase.substring(0, 0 + 1)), "");
phrase
现在是" "
,count
1
!Character.isLettorDigit(phrase.codePointAt(1) --> true
phrase.length() > 2 --> false
因此循环应该在异常发生之前中断。
任何提示?
答案 0 :(得分:5)
交换while
条件
while (count < pharse.length() && !Character.isLetterOrDigit(phrase.codePointAt(count))) {
这将导致Java在尝试从中提取字符之前检查count
是否小于phrase
的长度(请记住,它是0索引的)