考虑这个程序：
import java.util.regex.Pattern;
public class xx {
/*
* Ñ
* LATIN CAPITAL LETTER N WITH TILDE
* Unicode: U+00D1,UTF-8: C3 91
*/
public static final String BIG_N = "\u00d1";
/*
* ñ
* LATIN SMALL LETTER N WITH TILDE
* Unicode: U+00F1,UTF-8: C3 B1
*/
public static final String LITTLE_N = "\u00f1";
public static void main(String[] args) throws Exception {
System.out.println(BIG_N.equalsIgnoreCase(LITTLE_N));
System.out.println(Pattern.compile(BIG_N,Pattern.CASE_INSENSITIVE).matcher(LITTLE_N).matches());
}
}
由于Ñ是ñ的大写版本,您可以期望打印：
true true
但它实际打印(java 1.7.0_17-b02)是：
true false
为什么？
解决方法
By default,case-insensitive matching assumes that only characters in the US-ASCII charset are being matched. Unicode-aware case-insensitive matching can be enabled by specifying the UNICODE_CASE flag in conjunction with this flag.
http://docs.oracle.com/javase/7/docs/api/java/util/regex/Pattern.html#CASE_INSENSITIVE
为了完整;你或(|)旗帜在一起.
Pattern.compile(BIG_N,Pattern.CASE_INSENSITIVE | Pattern.UNICODE_CASE)