判断用户名只支持中英文和下划线
public static boolean checkLetterInvalid(String s)
{
char[] cs = s.toCharArray();
boolean flag = true;
for(char c:cs)
{
if(Character.isDigit(c))
{
continue;
}
if(Character.isLetter(c))
{
continue;
}
if(c == 95)
{
continue;
}
Character.UnicodeBlock ub = Character.UnicodeBlock.of(c);
if(ub == Character.UnicodeBlock.CJK_UNIFIED_IDEOGRAPHS)
{
continue;
}
flag = false;
break;
}
return flag;
}
