1. Oracle中IP转long 和Long转IP

create or replace function ip2number(ip varchar2)   
return number  
is  
  ip_num_hex varchar2(80);  
begin  
  if (regexp_like(ip, '^(/d{1,3})/.(/d{1,3})/.(/d{1,3})/.(/d{1,3})$')) then  
     ip_num_hex := lpad(trim(to_char(regexp_replace(ip, '^(/d{1,3})/.(/d{1,3})/.(/d{1,3})/.(/d{1,3})$', '/1'), 'XX')),2,'0') ||  
                   lpad(trim(to_char(regexp_replace(ip, '^(/d{1,3})/.(/d{1,3})/.(/d{1,3})/.(/d{1,3})$', '/2'), 'XX')),2,'0') ||  
                   lpad(trim(to_char(regexp_replace(ip, '^(/d{1,3})/.(/d{1,3})/.(/d{1,3})/.(/d{1,3})$', '/3'), 'XX')),2,'0') ||  
                   lpad(trim(to_char(regexp_replace(ip, '^(/d{1,3})/.(/d{1,3})/.(/d{1,3})/.(/d{1,3})$', '/4'), 'XX')),2,'0');  

     return to_number(ip_num_hex, 'XXXXXXXX');  
  else  
     return -1;  
  end if;  
exception  
when others then  
  return -99999999999;  
end;  

select ip2number('169.254.55.6') from dual;  

IP2NUMBER('169.254.55.6')  
-------------------------  
               2852009734  

create or replace function number2ip(num number)  
return varchar2 is  
  ip_num_hex varchar2(8);  
begin  
  ip_num_hex := lpad(trim(to_char(num, 'XXXXXXXX')), 8, '0');  
  return to_number(substr(ip_num_hex, 1, 2), 'XX') || '.' ||  
         to_number(substr(ip_num_hex, 3, 2), 'XX') || '.' ||  
         to_number(substr(ip_num_hex, 5, 2), 'XX') || '.' ||  
         to_number(substr(ip_num_hex, 7, 2), 'XX');  
exception  
when others then  
  dbms_output.put_line(sqlerrm);  
  return null;  
end;  

select number2ip(2852009734) from dual;  

NUMBER2IP(2852009734)                                                             
--------------------------------------------------------------------------------  
169.254.55.6    

2.java中实现方式

/** 
     * ip地址转成整数. 
     * @param ip 
     * @return 
     */  
    public static long ip2long(String ip) {  
        String[] ips = ip.split("[.]");  
        long num =  16777216L*Long.parseLong(ips[0]) + 65536L*Long.parseLong(ips[1]) + 256*Long.parseLong(ips[2]) + Long.parseLong(ips[3]);  
        return num;  
    }  

    /** 
     * 整数转成ip地址. 
     * @param ipLong 
     * @return 
     */  
    public static String long2ip(long ipLong) {  
        //long ipLong = 1037591503;  
        long mask[] = {0x000000FF,0x0000FF00,0x00FF0000,0xFF000000};  
        long num = 0;  
        StringBuffer ipInfo = new StringBuffer();  
        for(int i=0;i<4;i++){  
            num = (ipLong & mask[i])>>(i*8);  
            if(i>0) ipInfo.insert(0,".");  
            ipInfo.insert(0,Long.toString(num,10));  
        }  
        return ipInfo.toString();  
    }