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。