JAVA中IP和整数相互转化的方法

本文实例讲述了JAVA中IP和整数相互转化的方法。分享给大家供大家参考。具体分析如下：

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;
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实践: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]) + " ]");
 }
}

希望本文所述对大家的java程序设计有所帮助。