输入一个IP地址，判断该IP地址是IPv4，还是IPv6类地址

【题目】 输入一个IP地址，判断该IP地址是IPv4，还是IPv6类地址。

                使用正则表达式。

class Solution{
private static Pattern pattern;
private static Pattern ptipv4;
static {
// ipv6
pattern = Pattern.compile("^((([0-9A-Fa-f]{1,4}:){7}[0-9A-Fa-f]{1,4})|(([0-9A-Fa-f]{1,4}:){1,7}:)|(([0-9A-Fa-f]{1,4}:){6}:[0-9A-Fa-f]{1,4})|(([0-9A-Fa-f]{1,4}:){5}(:[0-9A-Fa-f]{1,4}){1,2})|(([0-9A-Fa-f]{1,4}:){4}(:[0-9A-Fa-f]{1,4}){1,3})|(([0-9A-Fa-f]{1,4}:){3}(:[0-9A-Fa-f]{1,4}){1,4})|(([0-9A-Fa-f]{1,4}:){2}(:[0-9A-Fa-f]{1,4}){1,5})|([0-9A-Fa-f]{1,4}:(:[0-9A-Fa-f]{1,4}){1,6})|(:(:[0-9A-Fa-f]{1,4}){1,7})|(([0-9A-Fa-f]{1,4}:){6}(\\d|[1-9]\\d|1\\d{2}|2[0-4]\\d|25[0-5])(\\.(\\d|[1-9]\\d|1\\d{2}|2[0-4]\\d|25[0-5])){3})|(([0-9A-Fa-f]{1,4}:){5}:(\\d|[1-9]\\d|1\\d{2}|2[0-4]\\d|25[0-5])(\\.(\\d|[1-9]\\d|1\\d{2}|2[0-4]\\d|25[0-5])){3})|(([0-9A-Fa-f]{1,4}:){4}(:[0-9A-Fa-f]{1,4}){0,1}:(\\d|[1-9]\\d|1\\d{2}|2[0-4]\\d|25[0-5])(\\.(\\d|[1-9]\\d|1\\d{2}|2[0-4]\\d|25[0-5])){3})|(([0-9A-Fa-f]{1,4}:){3}(:[0-9A-Fa-f]{1,4}){0,2}:(\\d|[1-9]\\d|1\\d{2}|2[0-4]\\d|25[0-5])(\\.(\\d|[1-9]\\d|1\\d{2}|2[0-4]\\d|25[0-5])){3})|(([0-9A-Fa-f]{1,4}:){2}(:[0-9A-Fa-f]{1,4}){0,3}:(\\d|[1-9]\\d|1\\d{2}|2[0-4]\\d|25[0-5])(\\.(\\d|[1-9]\\d|1\\d{2}|2[0-4]\\d|25[0-5])){3})|([0-9A-Fa-f]{1,4}:(:[0-9A-Fa-f]{1,4}){0,4}:(\\d|[1-9]\\d|1\\d{2}|2[0-4]\\d|25[0-5])(\\.(\\d|[1-9]\\d|1\\d{2}|2[0-4]\\d|25[0-5])){3})|(:(:[0-9A-Fa-f]{1,4}){0,5}:(\\d|[1-9]\\d|1\\d{2}|2[0-4]\\d|25[0-5])(\\.(\\d|[1-9]\\d|1\\d{2}|2[0-4]\\d|25[0-5])){3}))$");
// ipv4
ptipv4 = Pattern.compile("^(\\d|[1-9]\\d|1\\d{2}|2[0-4]\\d|25[0-5])(\\.(\\d|[1-9]\\d|1\\d{2}|2[0-4]\\d|25[0-5])){3}$");
}

public static String[] checkIPs(String[] ip_array) {

String[] str=new String[ip_array.length];
for(int i=0;i<ip_array.length;i++){
if(pattern.matcher(ip_array[i]).matches()){
str[i]= "IPv6";
}else if(ptipv4.matcher(ip_array[i]).matches() ){
str[i]="IPv4";
}else{
str[i]="Neither";
}
}
return str;
}

}