java ip地址转换为长整型

java ip地址转换为长整型；
public class Util {
   
     /**
     * 字符串ip转换为long
     * @param 字符串ip
     * @return
     */
    public static long getStringIpToLong(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; 
    } 
     
    /**
     * 长整型ip转换为string
     * @param long型ip
     * @return
     */ 
    public static String getLongIpToString(long ipLong) {  
       
        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(); 
    } 
}