The method of transforming IP and integer in Java _java

This article illustrates the method of transforming IP and integer in java. Share to everyone for your reference. The specific analysis is as follows:

I. Basic points of knowledge

ip--> integer:
Converts an IP address into an array of bytes
Convert to int by left shift (<<), with (&), or (|)
Integer--> IP:
The integer value is shifted to the right (>>>), 24 digits to the right, and the operator (&) 0xFF, and the resulting number is the first segment of IP.
The integer value is shifted to the right (>>>), 16 digits to the right, and the operator (&) 0xFF, and the resulting number is the second segment of IP.
The integer value is shifted to the right (>>>), 8 digits to the right, and the operator (&) 0xFF, and the resulting number is the third segment of IP.
The integer value is performed with the operator (&) 0xFF, and the resulting number is the fourth segment IP.

Second, Java code example (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 Practice: 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] <<) & 0xff0000); 
  Addr |= (Bytes[0] <<) & 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 >>>) & 0xFF); 
  IPADDR[1] = (byte) ((Ipint >>>) & 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 >>) & 0xff). Append ('. ') . Append ((Ipint >>) & 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 > To) {throw new IllegalArgumentException ("Invalid ipandmask with:" + IPANDMA 
  SK); 
  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 (ipAd 
  DR, 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 address segment: [" + ipscope[0] + "," + ipscope[1] + "]); System.out.println (Ipandmask + "--> IP address segment: [" + Ipv4util.inttoip (ipscope[0]) + "," + Ipv4util.inttoip (Ipsco 
  PE[1]) + "]"); 
  String IPADDR1 = "192.168.1.1", IpMask1 = "255.255.255.0"; 
  int[] Ipscope1 = Ipv4util.getipintscope (IPADDR1, IpMask1); 
  System.out.println (IpAddr1 + "," + IpMask1 + "--> int address segment: [" + ipscope1[0] + "," + ipscope1[1] + "]); System.out.println (IpAddr1 + "," + IpMask1 + "--> IP address segment: [" + Ipv4util.inttoip (ipscope1[0]) + "," + ipv4u 
 Til.inttoip (ipscope1[1]) + "]"); } 
}

I hope this article will help you with your Java programming.