控制ip范围内访问（转）

if(ipIsValid("192.168.100.1-192.168.100.255", localIp) || ipIsValid("200.100.192.0-200.100.192.20", localIp)) {
system.out.println("在ip范围内，可以访问！");
} else {
system.out.println("不在ip范围内，不可以访问！");
}

/**
* 检测用户ip是否在指定ip范围内
* @param string
* @param localIp
* @return
*/
private boolean ipIsValid(String ipSection, String ip) {

if (ipSection == null)
throw new NullPointerException("IP段不能为空！");
if (ip == null)
throw new NullPointerException("IP不能为空！");
ipSection = ipSection.trim();
ip = ip.trim();
final String REGX_IP = "(25[0-5]|2[0-4][0-9]|[0-1]{1}[0-9]{2}|[1-9]{1}[0-9]{1}|[1-9])\\.(25[0-5]|2[0-4][0-9]|[0-1]{1}[0-9]{2}|[1-9]{1}[0-9]{1}|[1-9]|0)\\.(25[0-5]|2[0-4][0-9]|[0-1]{1}[0-9]{2}|[1-9]{1}[0-9]{1}|[1-9]|0)\\.(25[0-5]|2[0-4][0-9]|[0-1]{1}[0-9]{2}|[1-9]{1}[0-9]{1}|[0-9])";
final String REGX_IPB = REGX_IP + "\\-" + REGX_IP;
if (!ipSection.matches(REGX_IPB) || !ip.matches(REGX_IP))
return false;
int idx = ipSection.indexOf('-');
String[] sips = ipSection.substring(0, idx).split("\\.");
String[] sipe = ipSection.substring(idx + 1).split("\\.");
String[] sipt = ip.split("\\.");
long ips = 0L, ipe = 0L, ipt = 0L;
for (int i = 0; i < 4; ++i) {
ips = ips << 8 | Integer.parseInt(sips[i]);
ipe = ipe << 8 | Integer.parseInt(sipe[i]);
ipt = ipt << 8 | Integer.parseInt(sipt[i]);
}
if (ips > ipe) {
long t = ips;
ips = ipe;
ipe = t;
}
return ips <= ipt && ipt <= ipe;
}