java判断是内网ip还是公网ip

public static boolean internalIp(String ip) {
 
    byte[] addr = IPAddressUtil.textToNumericFormatV4(ip);
 
    return internalIp(addr);
 
}  
 public static boolean internalIp(byte[] addr) {
 
    final byte b0 = addr[0];
 
    final byte b1 = addr[1];
 
    //10.x.x.x/8
 
    final byte SECTION_1 = 0x0A;
 
    //172.16.x.x/12
 
    final byte SECTION_2 = (byte) 0xAC;
 
    final byte SECTION_3 = (byte) 0x10;
 
    final byte SECTION_4 = (byte) 0x1F;
 
    //192.168.x.x/16
 
    final byte SECTION_5 = (byte) 0xC0;
 
    final byte SECTION_6 = (byte) 0xA8;
 
    switch (b0) {
 
        case SECTION_1:
 
            return true;
 
        case SECTION_2:
 
            if (b1 >= SECTION_3 && b1 <= SECTION_4) {
 
                return true;
 
            }
 
        case SECTION_5:
 
            switch (b1) {
 
                case SECTION_6:
 
                    return true;
 
            }
 
        default:
 
            return false;
 
    }
 
}