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JAVA中IP和整数相互转化介绍

作者:sjsky  发布日期:2011-06-22 20:38:41
Tag标签:JAVA  整数  相互  
  • 在项目中经常会用到IP(v4)范围判定比较的功能,一般将IP转化为整数再进行比较。
    一、基本知识点

     

    IP ——> 整数:

    •把IP地址转化为字节数组
    •通过左移位(<<)、与(&)、或(|)这些操作转为int
    整数 ——> IP:

    •将整数值进行右移位操作(>>>),右移24位,再进行与操作符(&)0xFF,得到的数字即为第一段IP。
    •将整数值进行右移位操作(>>>),右移16位,再进行与操作符(&)0xFF,得到的数字即为第二段IP。
    •将整数值进行右移位操作(>>>),右移8位,再进行与操作符(&)0xFF,得到的数字即为第三段IP。
    •将整数值进行与操作符(&)0xFF,得到的数字即为第四段IP。
    二、java代码示例

        IPv4Util.java


     

    package michael.utils;   
      
    import java.net.InetAddress;   
      
    /**  
     * @author michael <br>  
     *         blog: http://sjsky.iteye.com <br>  
     *         mail: sjsky007@gmail.com  
     */  
    public class IPv4Util {   
      
        private final static int INADDRSZ = 4;   
      
        /**  
         * 把IP地址转化为字节数组  
         * @param ipAddr  
         * @return byte[]  
         */  
        public static byte[] ipToBytesByInet(String ipAddr) {   
            try {   
                return InetAddress.getByName(ipAddr).getAddress();   
            } catch (Exception e) {   
                throw new IllegalArgumentException(ipAddr + " is invalid IP");   
            }   
        }   
      
        /**  
         * 把IP地址转化为int  
         * @param ipAddr  
         * @return int  
         */  
        public static byte[] ipToBytesByReg(String ipAddr) {   
            byte[] ret = new byte[4];   
            try {   
                String[] ipArr = ipAddr.split("\\.");   
                ret[0] = (byte) (Integer.parseInt(ipArr[0]) & 0xFF);   
                ret[1] = (byte) (Integer.parseInt(ipArr[1]) & 0xFF);   
                ret[2] = (byte) (Integer.parseInt(ipArr[2]) & 0xFF);   
                ret[3] = (byte) (Integer.parseInt(ipArr[3]) & 0xFF);   
                return ret;   
            } catch (Exception e) {   
                throw new IllegalArgumentException(ipAddr + " is invalid IP");   
            }   
      
        }   
      
        /**  
         * 字节数组转化为IP  
         * @param bytes  
         * @return int  
         */  
        public static String bytesToIp(byte[] bytes) {   
            return new StringBuffer().append(bytes[0] & 0xFF).append('.').append(   
                    bytes[1] & 0xFF).append('.').append(bytes[2] & 0xFF)   
                    .append('.').append(bytes[3] & 0xFF).toString();   
        }   
      
        /**  
         * 根据位运算把 byte[] -> int  
         * @param bytes  
         * @return int  
         */  
        public static int bytesToInt(byte[] bytes) {   
            int addr = bytes[3] & 0xFF;   
            addr |= ((bytes[2] << 8) & 0xFF00);   
            addr |= ((bytes[1] << 16) & 0xFF0000);   
            addr |= ((bytes[0] << 24) & 0xFF000000);   
            return addr;   
        }   
      
        /**  
         * 把IP地址转化为int  
         * @param ipAddr  
         * @return int  
         */  
        public static int ipToInt(String ipAddr) {   
            try {   
                return bytesToInt(ipToBytesByInet(ipAddr));   
            } catch (Exception e) {   
                throw new IllegalArgumentException(ipAddr + " is invalid IP");   
            }   
        }   
      
        /**  
         * ipInt -> byte[]  
         * @param ipInt  
         * @return byte[]  
         */  
        public static byte[] intToBytes(int ipInt) {   
            byte[] ipAddr = new byte[INADDRSZ];   
            ipAddr[0] = (byte) ((ipInt >>> 24) & 0xFF);   
            ipAddr[1] = (byte) ((ipInt >>> 16) & 0xFF);   
            ipAddr[2] = (byte) ((ipInt >>> 8) & 0xFF);   
            ipAddr[3] = (byte) (ipInt & 0xFF);   
            return ipAddr;   
        }   
      
        /**  
         * 把int->ip地址  
         * @param ipInt  
         * @return String  
         */  
        public static String intToIp(int ipInt) {   
            return new StringBuilder().append(((ipInt >> 24) & 0xff)).append('.')   
                    .append((ipInt >> 16) & 0xff).append('.').append(   
                            (ipInt >> 8) & 0xff).append('.').append((ipInt & 0xff))   
                    .toString();   
        }   
      
        /**  
         * 把1/24 转化为int数组范围  
         * @param ipAndMask  
         * @return int[]  
         */  
        public static int[] getIPIntScope(String ipAndMask) {   
      
            String[] ipArr = ipAndMask.split("/");   
            if (ipArr.length != 2) {   
                throw new IllegalArgumentException("invalid ipAndMask with: "  
                        + ipAndMask);   
            }   
            int netMask = Integer.valueOf(ipArr[1].trim());   
            if (netMask < 0 || netMask > 31) {   
                throw new IllegalArgumentException("invalid ipAndMask with: "  
                        + ipAndMask);   
            }   
            int ipInt = IPv4Util.ipToInt(ipArr[0]);   
            int netIP = ipInt & (0xFFFFFFFF << (32 - netMask));   
            int hostScope = (0xFFFFFFFF >>> netMask);   
            return new int[] { netIP, netIP + hostScope };   
      
        }   
      
        /**  
         * 把1/24 转化为IP数组范围  
         * @param ipAndMask  
         * @return String[]  
         */  
        public static String[] getIPAddrScope(String ipAndMask) {   
            int[] ipIntArr = IPv4Util.getIPIntScope(ipAndMask);   
            return new String[] { IPv4Util.intToIp(ipIntArr[0]),   
                    IPv4Util.intToIp(ipIntArr[0]) };   
        }   
      
        /**  
         * 根据IP 子网掩码(1 0)转化为IP段  
         * @param ipAddr ipAddr  
         * @param mask mask  
         * @return int[]  
         */  
        public static int[] getIPIntScope(String ipAddr, String mask) {   
      
            int ipInt;   
            int netMaskInt = 0, ipcount = 0;   
            try {   
                ipInt = IPv4Util.ipToInt(ipAddr);   
                if (null == mask || "".equals(mask)) {   
                    return new int[] { ipInt, ipInt };   
                }   
                netMaskInt = IPv4Util.ipToInt(mask);   
                ipcount = IPv4Util.ipToInt("255") - netMaskInt;   
                int netIP = ipInt & netMaskInt;   
                int hostScope = netIP + ipcount;   
                return new int[] { netIP, hostScope };   
            } catch (Exception e) {   
                throw new IllegalArgumentException("invalid ip scope express  ip:"  
                        + ipAddr + "  mask:" + mask);   
            }   
      
        }   
      
        /**  
         * 根据IP 子网掩码(1 0)转化为IP段  
         * @param ipAddr ipAddr  
         * @param mask mask  
         * @return String[]  
         */  
        public static String[] getIPStrScope(String ipAddr, String mask) {   
            int[] ipIntArr = IPv4Util.getIPIntScope(ipAddr, mask);   
            return new String[] { IPv4Util.intToIp(ipIntArr[0]),   
                    IPv4Util.intToIp(ipIntArr[0]) };   
        }   
      
        /**  
         * @param args  
         * @throws Exception  
         */  
        public static void main(String[] args) throws Exception {   
            String ipAddr = "1";   
      
            byte[] bytearr = IPv4Util.ipToBytesByInet(ipAddr);   
      
            StringBuffer byteStr = new StringBuffer();   
      
            for (byte b : bytearr) {   
                if (byteStr.length() == 0) {   
                    byteStr.append(b);   
                } else {   
                    byteStr.append("," + b);   
                }   
            }   
            System.out.println("IP: " + ipAddr + " ByInet --> byte[]: [ " + byteStr   
                    + " ]");   
      
            bytearr = IPv4Util.ipToBytesByReg(ipAddr);   
            byteStr = new StringBuffer();   
      
            for (byte b : bytearr) {   
                if (byteStr.length() == 0) {   
                    byteStr.append(b);   
                } else {   
                    byteStr.append("," + b);   
                }   
            }   
            System.out.println("IP: " + ipAddr + " ByReg  --> byte[]: [ " + byteStr   
                    + " ]");   
      
            System.out.println("byte[]: " + byteStr + " --> IP: "  
                    + IPv4Util.bytesToIp(bytearr));   
      
            int ipInt = IPv4Util.ipToInt(ipAddr);   
      
            System.out.println("IP: " + ipAddr + "  --> int: " + ipInt);   
      
            System.out.println("int: " + ipInt + " --> IP: "  
                    + IPv4Util.intToIp(ipInt));   
      
            String ipAndMask = "1/24";   
      
            int[] ipscope = IPv4Util.getIPIntScope(ipAndMask);   
            System.out.println(ipAndMask + " --> int地址段:[ " + ipscope[0] + ","  
                    + ipscope[1] + " ]");   
      
            System.out.println(ipAndMask + " --> IP 地址段:[ "  
                    + IPv4Util.intToIp(ipscope[0]) + ","  
                    + IPv4Util.intToIp(ipscope[1]) + " ]");   
      
            String ipAddr1 = "1", ipMask1 = "0";   
      
            int[] ipscope1 = IPv4Util.getIPIntScope(ipAddr1, ipMask1);   
            System.out.println(ipAddr1 + " , " + ipMask1 + "  --> int地址段 :[ "  
                    + ipscope1[0] + "," + ipscope1[1] + " ]");   
      
            System.out.println(ipAddr1 + " , " + ipMask1 + "  --> IP地址段 :[ "  
                    + IPv4Util.intToIp(ipscope1[0]) + ","  
                    + IPv4Util.intToIp(ipscope1[1]) + " ]");   
      
        }   
    }  
    
    

    运行结果: IP: 192.168.8.1 ByInet --> byte[]: [ -64,-88,8,1 ] IP: 192.168.8.1 ByReg  --> byte[]: [ -64,-88,8,1 ] byte[]: -64,-88,8,1 --> IP: 192.168.8.1 IP: 192.168.8.1  --> int: -1062729727 int: -1062729727 --> IP: 192.168.8.1 192.168.1.1/24 --> int地址段:[ -1062731520,-1062731265 ] 192.168.1.1/24 --> IP 地址段:[ 192.168.1.0,192.168.1.255 ] 192.168.1.1 , 255.255.255.0  --> int地址段 :[ -1062731520,-1062731265 ] 192.168.1.1 , 255.255.255.0  --> IP地址段 :[ 192.168.1.0,192.168.1.255 ]

     

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