一个ip地址用字符串保存,长度为(7-15)也就是(14-30bytes),而用int保存只需要4bytes,所以下面的代码:

/**	 * ip字符串转整数	 * ip是.分割的整数字符串,按照r进制转十进制的规律,按权相加求和,这里的权是256.	 * @param ip	 * @return	 */		public int ip2Int(String ip){		if(null == ip || "".equals(ip.trim()) || !checkIP(ip)) return 0;		String[] ipStrs = ip.split("\\.");//分割ip		int result = 0;		for(int i = 0;i < 4;i ++){			Integer ipSubInteger = Integer.parseInt(ipStrs[i]);			if(ipSubInteger > 255) {//正则验证不能为负数				result = 0;				break;			}			result += (ipSubInteger << (24 - i * 8));		}		return result;	}		/*正则验证ip*/	private boolean checkIP(String ip){		return ip.matches("\\d{1,3}(\\.\\d{1,3}){3}");	}		/**	 * 整数转ip	 * @param ip	 * @return	 */	public String int2Ip(int ip){		StringBuilder builder = new StringBuilder(String.valueOf(ip >>> 24));		builder.append(".");		builder.append(String.valueOf((ip & 0X00FFFFFF) >>> 16));		builder.append(".");		builder.append(String.valueOf((ip & 0X0000FFFF) >>> 8));		builder.append(".");		builder.append(String.valueOf(ip & 0X000000FF));		return builder.toString();	}