我有ip地址和10.1.1.1/32等掩码。我想检查10.1.1.1是否在该范围内。是否有可以执行此操作的库或实用程序，或者我是否需要自己编写某些内容？
答案 0 :(得分：29)
首先，您需要将IP地址转换为平面int，这样更容易使用：
String s = "10.1.1.99";
Inet4Address a = (Inet4Address) InetAddress.getByName(s);
byte[] b = a.getAddress();
int i = ((b[0] & 0xFF) << 24) |
((b[1] & 0xFF) << 16) |
((b[2] & 0xFF) << 8) |
((b[3] & 0xFF) << 0);
将IP地址设为普通int后，您可以执行一些算术运算来执行检查：
int subnet = 0x0A010100; // 10.1.1.0/24
int bits = 24;
int ip = 0x0A010199; // 10.1.1.99
// Create bitmask to clear out irrelevant bits. For 10.1.1.0/24 this is
// 0xFFFFFF00 -- the first 24 bits are 1's, the last 8 are 0's.
//
// -1 == 0xFFFFFFFF
// 32 - bits == 8
// -1 << 8 == 0xFFFFFF00
mask = -1 << (32 - bits)
if ((subnet & mask) == (ip & mask)) {
// IP address is in the subnet.
}
答案 1 :(得分：3)
public static boolean netMatch(String addr, String addr1){ //addr is subnet address and addr1 is ip address. Function will return true, if addr1 is within addr(subnet)
String[] parts = addr.split("/");
String ip = parts[0];
int prefix;
if (parts.length < 2) {
prefix = 0;
} else {
prefix = Integer.parseInt(parts[1]);
}
Inet4Address a =null;
Inet4Address a1 =null;
try {
a = (Inet4Address) InetAddress.getByName(ip);
a1 = (Inet4Address) InetAddress.getByName(addr1);
} catch (UnknownHostException e){}
byte[] b = a.getAddress();
int ipInt = ((b[0] & 0xFF) << 24) |
((b[1] & 0xFF) << 16) |
((b[2] & 0xFF) << 8) |
((b[3] & 0xFF) << 0);
byte[] b1 = a1.getAddress();
int ipInt1 = ((b1[0] & 0xFF) << 24) |
((b1[1] & 0xFF) << 16) |
((b1[2] & 0xFF) << 8) |
((b1[3] & 0xFF) << 0);
int mask = ~((1 << (32 - prefix)) - 1);
if ((ipInt & mask) == (ipInt1 & mask)) {
return true;
}
else {
return false;
}
}
答案 2 :(得分：3)
这是一个以几种常见方式获取子网描述的版本，包括 IPv6 。
根据此处发布的其他代码。
在 IPv4 地址上，它可能比在int上执行二进制操作的方法更慢。
package de.c3oe.tryanderror;
import java.math.BigInteger;
import java.net.InetAddress;
import java.net.UnknownHostException;
/**
* @author c3oe.de, based on snippets from Scott Plante, John Kugelmann
*/
public class Subnet
{
final private int bytesSubnetCount;
final private BigInteger bigMask;
final private BigInteger bigSubnetMasked;
/** For use via format "192.168.0.0/24" or "2001:db8:85a3:880:0:0:0:0/57" */
public Subnet( final InetAddress subnetAddress, final int bits )
{
this.bytesSubnetCount = subnetAddress.getAddress().length; // 4 or 16
this.bigMask = BigInteger.valueOf( -1 ).shiftLeft( this.bytesSubnetCount*8 - bits ); // mask = -1 << 32 - bits
this.bigSubnetMasked = new BigInteger( subnetAddress.getAddress() ).and( this.bigMask );
}
/** For use via format "192.168.0.0/255.255.255.0" or single address */
public Subnet( final InetAddress subnetAddress, final InetAddress mask )
{
this.bytesSubnetCount = subnetAddress.getAddress().length;
this.bigMask = null == mask ? BigInteger.valueOf( -1 ) : new BigInteger( mask.getAddress() ); // no mask given case is handled here.
this.bigSubnetMasked = new BigInteger( subnetAddress.getAddress() ).and( this.bigMask );
}
/**
* Subnet factory method.
* @param subnetMask format: "192.168.0.0/24" or "192.168.0.0/255.255.255.0"
* or single address or "2001:db8:85a3:880:0:0:0:0/57"
* @return a new instance
* @throws UnknownHostException thrown if unsupported subnet mask.
*/
public static Subnet createInstance( final String subnetMask )
throws UnknownHostException
{
final String[] stringArr = subnetMask.split("/");
if ( 2 > stringArr.length )
return new Subnet( InetAddress.getByName( stringArr[ 0 ] ), (InetAddress)null );
else if ( stringArr[ 1 ].contains(".") || stringArr[ 1 ].contains(":") )
return new Subnet( InetAddress.getByName( stringArr[ 0 ] ), InetAddress.getByName( stringArr[ 1 ] ) );
else
return new Subnet( InetAddress.getByName( stringArr[ 0 ] ), Integer.parseInt( stringArr[ 1 ] ) );
}
public boolean isInNet( final InetAddress address )
{
final byte[] bytesAddress = address.getAddress();
if ( this.bytesSubnetCount != bytesAddress.length )
return false;
final BigInteger bigAddress = new BigInteger( bytesAddress );
return bigAddress.and( this.bigMask ).equals( this.bigSubnetMasked );
}
@Override
final public boolean equals( Object obj )
{
if ( ! (obj instanceof Subnet) )
return false;
final Subnet other = (Subnet)obj;
return this.bigSubnetMasked.equals( other.bigSubnetMasked ) &&
this.bigMask.equals( other.bigMask ) &&
this.bytesSubnetCount == other.bytesSubnetCount;
}
@Override
final public int hashCode()
{
return this.bytesSubnetCount;
}
@Override
public String toString()
{
final StringBuilder buf = new StringBuilder();
bigInteger2IpString( buf, this.bigSubnetMasked, this.bytesSubnetCount );
buf.append( '/' );
bigInteger2IpString( buf, this.bigMask, this.bytesSubnetCount );
return buf.toString();
}
static private void bigInteger2IpString( final StringBuilder buf, final BigInteger bigInteger, final int displayBytes )
{
final boolean isIPv4 = 4 == displayBytes;
byte[] bytes = bigInteger.toByteArray();
int diffLen = displayBytes - bytes.length;
final byte fillByte = 0 > (int)bytes[ 0 ] ? (byte)0xFF : (byte)0x00;
int integer;
for ( int i = 0; i < displayBytes; i++ )
{
if ( 0 < i && ! isIPv4 && i % 2 == 0 )
buf.append( ':' );
else if ( 0 < i && isIPv4 )
buf.append( '.' );
integer = 0xFF & (i < diffLen ? fillByte : bytes[ i - diffLen ]);
if ( ! isIPv4 && 0x10 > integer )
buf.append( '0' );
buf.append( isIPv4 ? integer : Integer.toHexString( integer ) );
}
}
}
答案 3 :(得分：1)
感谢John Kugelman - 我使用他的代码片段来创建这个类。
package bs;
import java.net.Inet4Address;
import java.net.InetAddress;
import java.net.UnknownHostException;
/**
* Represents an IP range based on an address/mask.
* @author Scott Plante, using code snippets by John Kugelman.
*/
public class IPMask
{
public static void main(String args[])
throws UnknownHostException
{
IPMask ipmask;
ipmask = IPMask.getIPMask("192.168.20.32/24");
System.out.println("Checking "+ipmask+"...");
test(ipmask, "192.168.20.31 ", true);
test(ipmask, "192.168.20.32 ", true);
test(ipmask, "192.168.20.33 ", true);
test(ipmask, "192.168.20.34 ", true);
test(ipmask, "192.168.20.35 ", true);
test(ipmask, "192.168.20.36 ", true);
test(ipmask, "192.168.20.254", true);
test(ipmask, "192.168.20.157", true);
test(ipmask, "192.168.21.1 ", false);
test(ipmask, "192.168.19.255", false);
test(ipmask, "192.168.24.1 ", false);
ipmask = IPMask.getIPMask("192.168.20.32/31");
System.out.println("Checking "+ipmask+"...");
test(ipmask, "192.168.20.31 ", false);
test(ipmask, "192.168.20.32 ", true);
test(ipmask, "192.168.20.33 ", true);
test(ipmask, "192.168.20.34 ", false);
test(ipmask, "192.168.20.35 ", false);
test(ipmask, "192.168.20.36 ", false);
test(ipmask, "192.168.20.254", false);
test(ipmask, "192.168.20.157", false);
test(ipmask, "192.168.21.1 ", false);
test(ipmask, "192.168.19.255", false);
test(ipmask, "192.168.24.1 ", false);
ipmask = IPMask.getIPMask("192.168.20.32/23");
System.out.println("Checking "+ipmask+"...");
test(ipmask, "192.168.20.31 ", true);
test(ipmask, "192.168.20.32 ", true);
test(ipmask, "192.168.20.33 ", true);
test(ipmask, "192.168.20.254", true);
test(ipmask, "192.168.21.254", true);
test(ipmask, "192.168.19.255", false);
test(ipmask, "192.168.24.1 ", false);
}
public static void test(IPMask ipmask, String addr, boolean expect)
throws UnknownHostException
{
boolean got = ipmask.matches(addr);
System.out.println(addr + "\t(" + expect + ") ?\t"+got
+ "\t" + (got==expect?"":"!!!!!!!!"));
}
private Inet4Address i4addr;
private byte maskCtr;
private int addrInt;
private int maskInt;
public IPMask(Inet4Address i4addr, byte mask)
{
this.i4addr = i4addr;
this.maskCtr = mask;
this.addrInt = addrToInt(i4addr);
this.maskInt = ~((1 << (32 - maskCtr)) - 1);
}
/** IPMask factory method.
*
* @param addrSlashMask IP/Mask String in format "nnn.nnn.nnn.nnn/mask". If
* the "/mask" is omitted, "/32" (just the single address) is assumed.
* @return a new IPMask
* @throws UnknownHostException if address part cannot be parsed by
* InetAddress
*/
public static IPMask getIPMask(String addrSlashMask)
throws UnknownHostException
{
int pos = addrSlashMask.indexOf('/');
String addr;
byte maskCtr;
if (pos==-1)
{
addr = addrSlashMask;
maskCtr = 32;
}
else
{
addr = addrSlashMask.substring(0, pos);
maskCtr = Byte.parseByte(addrSlashMask.substring(pos + 1));
}
return new IPMask((Inet4Address) InetAddress.getByName(addr), maskCtr);
}
/** Test given IPv4 address against this IPMask object.
*
* @param testAddr address to check.
* @return true if address is in the IP Mask range, false if not.
*/
public boolean matches(Inet4Address testAddr)
{
int testAddrInt = addrToInt(testAddr);
return ((addrInt & maskInt) == (testAddrInt & maskInt));
}
/** Convenience method that converts String host to IPv4 address.
*
* @param addr IP address to match in nnn.nnn.nnn.nnn format or hostname.
* @return true if address is in the IP Mask range, false if not.
* @throws UnknownHostException if the string cannot be decoded.
*/
public boolean matches(String addr)
throws UnknownHostException
{
return matches((Inet4Address)InetAddress.getByName(addr));
}
/** Converts IPv4 address to integer representation.
*/
private static int addrToInt(Inet4Address i4addr)
{
byte[] ba = i4addr.getAddress();
return (ba[0] << 24)
| ((ba[1]&0xFF) << 16)
| ((ba[2]&0xFF) << 8)
| (ba[3]&0xFF);
}
@Override
public String toString()
{
return "IPMask(" + i4addr.getHostAddress() + "/" + maskCtr + ")";
}
@Override
public boolean equals(Object obj)
{
if (obj == null)
return false;
if (getClass() != obj.getClass())
return false;
final IPMask that = (IPMask) obj;
return (this.addrInt == that.addrInt && this.maskInt == that.maskInt);
}
@Override
public int hashCode()
{
return this.maskInt + this.addrInt;
}
}
我必须在他的代码中为int转换添加一个掩码：
Inet4Address a = (Inet4Address) InetAddress.getByName("192.192.192.192");
byte[] b = a.getAddress();
int i = (b[0] << 24) | (b[1] << 16) | (b[2] << 8) | (b[3] << 0);
System.out.println(Integer.toHexString(i));
System.out.println(Integer.toHexString(addrToInt(a)));
制作人：
ffffffc0
c0c0c0c0
在我的系统上：
$> uname -a
Linux guin 2.6.37.6-0.5-desktop #1 SMP PREEMPT 2011-04-25 21:48:33 +0200 x86_64 x86_64 x86_64 GNU/Linux
$> java -version
java version "1.6.0_25"
Java(TM) SE Runtime Environment (build 1.6.0_25-b06)
Java HotSpot(TM) 64-Bit Server VM (build 20.0-b11, mixed mode)
$>
您可以从上面的类中删除main和test方法。它们是从单元测试代码改编而来的，为简单起见而添加到这里。
答案 4 :(得分：1)
这只是open-source IPAddress Java library的几行代码。免责声明：我是IPAddress库的项目经理。
String subnetStr = "10.1.1.1/24";
String addrStr = "10.1.1.1";
IPAddress subnetAddress = new IPAddressString(subnetStr).getAddress();
IPAddress subnet = subnetAddress.toPrefixBlock();
IPAddress testAddress = new IPAddressString(addrStr).getAddress();
boolean result = subnet.contains(testAddress);
System.out.println(subnetAddress + " is in subnet " + subnet + " and " +
(result ? "contains" : "does not contain") + " address " + testAddress);
输出：
10.1.1.1/24 is in subnet 10.1.1.0/24 and contains address 10.1.1.1
答案 5 :(得分：1)
我相信有一个commons-ip-math库很不错。请注意，截至2019年5月，该库两年未进行任何更新（可能是其已经非常成熟的库）。它在maven-central
上可用它支持同时使用IPv4和IPv6地址。他们的简要文档提供了有关如何检查IPv4和IPv6
的地址是否在特定范围内的示例。用于IPv4范围检查的示例：
String input1 = "10.1.1.1";
Ipv4 ipv41 = Ipv4.parse(input1);
// Using CIDR notation to specify the networkID and netmask
Ipv4Range range = Ipv4Range.parse("10.1.1.1/32");
boolean result = range.contains(ipv41);
System.out.println(result); //true
String input2 = "10.1.1.1";
Ipv4 ipv42 = Ipv4.parse(input2);
// Specifying the range with a start and end.
Ipv4 start = Ipv4.of("10.1.1.1");
Ipv4 end = Ipv4.of("10.1.1.1");
range = Ipv4Range.from(start).to(end);
result = range.contains(ipv42); //true
System.out.println(result);