The method of transforming IP and integer in 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

Via left shift (<<), with (&), or (|) These operations are converted to int

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)

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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) {THR ow new IllegalArgumentException (ipaddr + "is invalid IP"); } public static byte[] Inttobytes (int ipint) {byte[] ipaddr = new Byte[inaddrsz]; ipaddr[0] = (byte) (Ipint >>&G T ) & 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) {th Row new IllegalArgumentException ("Invalid ipandmask with:" + Ipandmask);} int netMask = integer.valueof (Iparr[1].trim ()); if (NetMask < 0 | | NetMask > To) {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); 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.iptob Ytesbyinet (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 (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 address segment: [" + ipscope1[0] + "," + ipscope1[1] + "]); System.out.println (IpAddr1 + "," + IpMask1 + "--> IP address segment: [" + Ipv4util.inttoip (ipscope1[0]) + "," + Ipv4util.intto Ip (ipscope1[1]) + "]"); } }

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