java 子网掩码和IP计算起始IP和终止IP工具类

1.根据掩码位数获取掩码

2.根据ip地址和掩码获取起始IP

3.根据ip地址和掩码获取终止IP

4.ip转换Long

5.实际可用ip数量

public class NetAddressUtils {/*** 根据掩码位数获取掩码*/public static String getNetMask(String mask) {int inetMask =Integer.parseInt(mask);if(inetMask > 32){return null;}//子网掩码为1占了几个字节int num1 = inetMask/8;//子网掩码的补位位数int num2 = inetMask%8;int array[] = new int[4];for (int i = 0; i < num1; i++) {array[i] = 255;}for (int i = num1; i < 4; i++) {array[i] = 0;}for (int i = 0; i < num2; num2--) {array[num1] += Math.pow(2, 8-num2);}return  array[0] + "." + array[1] + "." + array[2] + "." + array[3];}/*** 根据ip地址和掩码获取起始IP* @param ipinfo* @param netMask* @return*/public static String getLowAddr(String ipinfo, String netMask) {String lowAddr = "";int ipArray[] = new int[4];int netMaskArray[] = new int[4];if(4 != ipinfo.split("\\.").length || "" == netMask){return null;}for (int i = 0; i < 4; i++) {try{ipArray[i] = Integer.parseInt(ipinfo.split("\\.")[i]);}catch(NumberFormatException e){String ip = ipinfo.replaceAll("\n", "");ipArray[i] = Integer.parseInt(ip.split("\\.")[i]);}netMaskArray[i] = Integer.parseInt(netMask.split("\\.")[i]);if(ipArray[i] > 255 || ipArray[i] < 0 || netMaskArray[i] > 255 || netMaskArray[i] < 0){return null;}ipArray[i] = ipArray[i]&netMaskArray[i];}//构造最小地址for (int i = 0; i < 4; i++){if(i == 3){ipArray[i] = ipArray[i] + 1;}if ("" == lowAddr){lowAddr +=ipArray[i];} else{lowAddr += "." + ipArray[i];}}return lowAddr;}/*** 根据ip地址和掩码获取终止IP* @param ipinfo* @param netMask* @return*/public static String getHighAddr(String ipinfo, String netMask) {String lowAddr = getLowAddr(ipinfo, netMask);int hostNumber = getHostNumber(netMask);if("" == lowAddr || hostNumber == 0){return null;}int lowAddrArray[] = new int[4];for (int i = 0; i < 4; i++) {lowAddrArray[i] = Integer.parseInt(lowAddr.split("\\.")[i]);if(i == 3){lowAddrArray[i] = lowAddrArray[i] - 1;}}lowAddrArray[3] = lowAddrArray[3] + (hostNumber - 1);if(lowAddrArray[3] >255){int k = lowAddrArray[3] / 256;lowAddrArray[3] = lowAddrArray[3] % 256;lowAddrArray[2] = lowAddrArray[2] + k;}if(lowAddrArray[2] > 255){int  j = lowAddrArray[2] / 256;lowAddrArray[2] = lowAddrArray[2] % 256;lowAddrArray[1] = lowAddrArray[1] + j;if(lowAddrArray[1] > 255){int  k = lowAddrArray[1] / 256;lowAddrArray[1] = lowAddrArray[1] % 256;lowAddrArray[0] = lowAddrArray[0] + k;}}String highAddr = "";for(int i = 0; i < 4; i++){if(i == 3){lowAddrArray[i] = lowAddrArray[i] - 1;}if("" == highAddr){highAddr = lowAddrArray[i]+"";}else{highAddr += "." + lowAddrArray[i];}}return highAddr;}/*** ip转换Long* @param ip* @return*/public static long ip2long(String ip) {String[] ips = ip.split("[.]");if (ips.length != 4 || "".equals(ip)) {return 0;} else {return 16777216L * Long.parseLong(ips[0]) + 65536L* Long.parseLong(ips[1]) + 256 * Long.parseLong(ips[2])+ Long.parseLong(ips[3]);}}/*** 实际可用ip数量* @param netMask* @return*/public static int getHostNumber(String netMask) {int hostNumber = 0;int netMaskArray[] = new int[4];for (int i = 0; i < 4 ; i++) {netMaskArray[i] = Integer.parseInt(netMask.split("\\.")[i]);if(netMaskArray[i] < 255){hostNumber =  (int) (Math.pow(256,3-i) * (256 - netMaskArray[i]));break;}}return hostNumber;}public static int getNetMaskNumber(String netMask) {int netMaskNumber = 0;switch (netMask) {case "255.255.255.255":netMaskNumber = 32;break;case "255.255.255.254":netMaskNumber = 31;break;case "255.255.255.252":netMaskNumber = 30;break;case "255.255.255.248":netMaskNumber = 29;break;case "255.255.255.240":netMaskNumber = 28;break;case "255.255.255.224":netMaskNumber = 27;break;case "255.255.255.192":netMaskNumber = 26;break;case "255.255.255.128":netMaskNumber = 25;break;case "255.255.255.0":netMaskNumber = 24;break;case "255.255.254.0":netMaskNumber = 23;break;case "255.255.252.0":netMaskNumber = 22;break;case "255.255.248.0":netMaskNumber = 21;break;case "255.255.240.0":netMaskNumber = 20;break;}return netMaskNumber;}//    public static void main(String[] args) throws Exception {
//        /*
//         * 10.197.12.0	255.255.254.0	 10.197.12.1 	10.197.13.254	Used	210
//         * 10.202.123.0	255.255.255.0	10.202.123.1	10.202.123.254	Used	11
//         * 10.194.220.0	255.255.255.224	10.194.220.1	10.194.220.254	Used	22
//         * 10.102.161.0	255.255.255.0	10.102.161.1	10.102.161.254	Used	12
//         */
//        String ip = "10.194.220.0";
//        String netmask = "255.255.255.224";
        String startIp = NetAddressUtils.getLowAddr(ip, netmask);
        String endIp = NetAddressUtils.getHighAddr(ip, netmask);
        System.out.println("start ip: " + startIp);
        System.out.println("end ip: " + endIp);
        System.out.println("amount: " +
                (NetAddressUtils.ip2long(endIp) - NetAddressUtils.ip2long(startIp) + 1));
//
//        int ss = getHostNumber(netmask);
//        System.out.println(ss);
//        String aa  = getNetMask("28");
//        System.out.println(aa);
//    }}