本文實例講述了JAVA中IP和整數相互轉化的方法。分享給大家供大家參考。具體分析如下：
一、基本知識點
IP ——> 整數：
把IP地址轉化為字節數組
通過左移位(<<)、與(&)、或(|)這些操作轉為int
整數 ——> IP：
將整數值進行右移位操作(>>>)，右移24位，再進行與操作符(&)0xFF，得到的數字即為第一段IP。
將整數值進行右移位操作(>>>)，右移16位，再進行與操作符(&)0xFF，得到的數字即為第二段IP。
將整數值進行右移位操作(>>>)，右移8位，再進行與操作符(&)0xFF，得到的數字即為第三段IP。
將整數值進行與操作符(&)0xFF，得到的數字即為第四段IP。
二、java代碼示例(IPv4Util.java)
?
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 package michael.utils; import java.net.InetAddress; public class IPv4Util { private final static int INADDRSZ = 4; public static byte[] ipToBytesByInet(String ipAddr) { try { return InetAddress.getByName(ipAddr).getAddress(); } catch (Exception e) { throw new IllegalArgumentException(ipAddr + " is invalid IP"); } }JTA實踐:Spring+ATOMIKOS 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"); } } 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(); } 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; } public static int ipToInt(String ipAddr) { try { return bytesToInt(ipToBytesByInet(ipAddr)); } catch (Exception e) { throw new IllegalArgumentException(ipAddr + " is invalid IP"); } } 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; } 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(); } 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 }; } public static String[] getIPAddrScope(String ipAndMask) { int[] ipIntArr = IPv4Util.getIPIntScope(ipAndMask); return new String[] { IPv4Util.intToIp(ipIntArr[0]), IPv4Util.intToIp(ipIntArr[0]) }; } 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("255.255.255.255") - 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); } } 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]) }; } public static void main(String[] args) throws Exception { String ipAddr = "192.168.8.1"; 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 = "192.168.1.1/24"; 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 = "192.168.1.1", ipMask1 = "255.255.255.0"; 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]) + " ]"); } }希望本文所述對大家的java程序設計有所幫助。
