ipv4address.java

来自「纯java操作系统jnode,安装简单和操作简单的个人使用的Java操作系统」· Java 代码 · 共 332 行

/*
 * $Id: IPv4Address.java,v 1.1 2003/11/25 11:52:24 epr Exp $
 */
package org.jnode.net.ipv4;

import java.io.Serializable;
import java.net.InetAddress;
import java.net.UnknownHostException;
import java.util.StringTokenizer;

import org.jnode.net.ProtocolAddress;
import org.jnode.net.SocketBuffer;
import org.jnode.net.ethernet.EthernetConstants;

/**
 * @author epr
 */
public class IPv4Address implements ProtocolAddress, Serializable {
	
	private final static int length = 4;
	private final byte[] address;
	private InetAddress inetAddress;
	
	public static final IPv4Address ANY = new IPv4Address("0.0.0.0");
	public static final IPv4Address BROADCAST = new IPv4Address("255.255.255.255");

	private static final IPv4Address DEFAULT_ANY_SUBNETMASK = new IPv4Address("0.0.0.0");
	private static final IPv4Address DEFAULT_CLASS_A_SUBNETMASK = new IPv4Address("255.0.0.0");
	private static final IPv4Address DEFAULT_CLASS_B_SUBNETMASK = new IPv4Address("255.255.0.0");
	private static final IPv4Address DEFAULT_CLASS_C_SUBNETMASK = new IPv4Address("255.255.255.0");
	private static final IPv4Address DEFAULT_CLASS_D_SUBNETMASK = new IPv4Address("255.255.255.0");
	
	/**
	 * Create a new instance
	 * @param src
	 * @param offset
	 */
	public IPv4Address(byte[] src, int offset) { 
		address = new byte[length];
		System.arraycopy(src, offset, address, 0, length);
	}

	/**
	 * Create a new instance
	 * @param skbuf
	 * @param offset
	 */
	public IPv4Address(SocketBuffer skbuf, int offset) { 
		address = new byte[length];
		skbuf.get(address, 0, offset, length);
	}
	
	/**
	 * Create a new instance from a String representation
	 * @param addrStr
	 * @throws IllegalArgumentException
	 */
	public IPv4Address(String addrStr) 
	throws IllegalArgumentException {
		final StringTokenizer tok = new StringTokenizer(addrStr, ".");
		if (tok.countTokens() != length) {
			throw new IllegalArgumentException("Not an IPv4 address " + addrStr);
		}
		address = new byte[length];
		for (int i = 0; i < length; i++) {
			try {
				address[i] = (byte)Integer.parseInt(tok.nextToken());
			} catch (NumberFormatException ex) {
				throw new IllegalArgumentException("Not a valid IPv4 address " + addrStr);
			}
		}
	}
	
	/**
	 * Create a new instance from a java.net.InetAddress
	 * @param inetAddress
	 */
	public IPv4Address(InetAddress inetAddress) {
		this.inetAddress = inetAddress;
		this.address = inetAddress.getAddress();
		if (address.length != length) {
			throw new IllegalArgumentException("inetAddress.length is incorrect");
		}
	}
	
	/**
	 * Is this address equal to the given address?
	 */
	public final boolean equals(IPv4Address other) {
		if (other == null) {
			return false;
		}
		for (int i = 0; i < length; i++) {
			if (address[i] != other.address[i]) {
				return false;
			}
		}
		return true;
	}	

	/**
	 * Is this address equal to the given address.
	 * @param o
	 */
	public boolean equals(ProtocolAddress o) {
		if (o instanceof IPv4Address) {
			return equals((IPv4Address)o);
		} else {
			return false;
		}
	}
	
	/**
	 * @see java.lang.Object#equals(java.lang.Object)
	 */
	public final boolean equals(Object obj) {
		if (obj instanceof IPv4Address) {
			return equals((IPv4Address)obj);
		} else {
			return false;
		}
	}

	/**
	 * Gets the length of this address in bytes
	 */
	public final int getLength() {
		return length;
	}
	
	/**
	 * Gets the address-byte at a given index
	 * @param index
	 */
	public final byte get(int index) {
		return address[index];
	}
	
	/**
	 * Write this address to a given offset in the given buffer
	 * @param skbuf
	 * @param skbufOffset
	 */
	public final void writeTo(SocketBuffer skbuf, int skbufOffset) {
		skbuf.set(skbufOffset, address, 0, length);
	}

	/**
	 * @see java.lang.Object#toString()
	 */
	public String toString() {
		return "" + (address[0] & 0xFF) + '.' +
		        (address[1] & 0xFF) + '.' +
				(address[2] & 0xFF) + '.' +
				(address[3] & 0xFF);
	}

	/**
	 * @see java.lang.Object#hashCode()
	 */
	public int hashCode() {
		final int v0 = address[0] & 0xFF;
		final int v1 = address[1] & 0xFF;
		final int v2 = address[2] & 0xFF;
		final int v3 = address[3] & 0xFF;
		return (v3 << 24) | (v2 << 16) | (v1 << 8) | v0;
	}
	
	/** 
	 * Is this a class A address.
	 * Class A = 0.0.0.0 - 127.255.255.255
	 */
	public boolean isClassA() {
		final int b0 = address[0] & 0xFF;
		return (b0 >= 0) && (b0 <= 127);
	}
	
	/** 
	 * Is this a class B address.
	 * Class B = 128.0.0.0 - 191.255.255.255
	 */
	public boolean isClassB() {
		final int b0 = address[0] & 0xFF;
		return (b0 >= 128) && (b0 <= 191);
	}
	
	/** 
	 * Is this a class C address.
	 * Class C = 192.0.0.0 - 223.255.255.255
	 */
	public boolean isClassC() {
		final int b0 = address[0] & 0xFF;
		return (b0 >= 192) && (b0 <= 223);
	}
	
	/** 
	 * Is this a class D (multicast) address.
	 * Class D = 224.0.0.0 - 239.255.255.255
	 */
	public boolean isClassD() {
		final int b0 = address[0] & 0xFF;
		return (b0 >= 224) && (b0 <= 239);
	}
	
	/** 
	 * Is this a class E (experimental) address.
	 * Class E = 240.0.0.0 - 247.255.255.255
	 */
	public boolean isClassE() {
		final int b0 = address[0] & 0xFF;
		return (b0 >= 240) && (b0 <= 247);
	}
	
	/** 
	 * Is this an unicast address.
	 * Unicast = 0.0.0.0 - 223.255.255.255
	 */
	public boolean isUnicast() {
		final int b0 = address[0] & 0xFF;
		return (b0 >= 0) && (b0 <= 223);
	}

	/** 
	 * Is this a multicast address.
	 * Multicast = 224.0.0.0 - 239.255.255.255
	 */
	public boolean isMulticast() {
		final int b0 = address[0] & 0xFF;
		return (b0 >= 224) && (b0 <= 239);
	}
	
	/** 
	 * Is this a broadcast address.
	 * Broadcast = hostID = -1
	 */
	public boolean isBroadcast() {
		final int b3 = address[3] & 0xFF;
		return (b3 == 0xFF);
	}
	
	/**
	 * Is this a host address.
	 * A host address has <code>hostID != 0</code>
	 */
	public boolean isHost() {
		final int b3 = address[3] & 0xFF;
		return (b3 != 0);
	}
	
	/**
	 * Is this an Any address.
	 * An Any address is equal to "0.0.0.0"
	 */
	public boolean isAny() {
		for (int i = 0; i < length; i++) {
			if (address[i] != 0) {
				return false;
			}
		}
		return true;
	}
	
	/**
	 * Is this a network address.
	 * A network address has <code>hostID == 0</code>
	 */
	public boolean isNetwork() {
		final int b3 = address[3] & 0xFF;
		return (b3 == 0);
	}
	
	/**
	 * Does this address matches a given mask?
	 * @param mask
	 */
	public boolean matches(IPv4Address otherAddress, IPv4Address mask) {
		for (int i = 0; i < length; i++) {
			final int a = address[i] & 0xFF;
			final int o = otherAddress.address[i] & 0xFF;
			final int m = mask.address[i] & 0xFF;
			if ((a & m) != (o & m)) {
				return false;
			}
		}
		return true;
	}

	/**
	 * Convert to a java.net.InetAddress
	 * @see java.net.InetAddress
	 * @see java.net.Inet4Address
	 * @return This address as java.net.InetAddress
	 */	
	public InetAddress toInetAddress() {
		if (inetAddress == null) {
			try {
				inetAddress = InetAddress.getByAddress(address);
			} catch (UnknownHostException ex) {
				throw new RuntimeException(ex);
			}
		}
		return inetAddress;
	}
	
	/**
	 * Gets the default subnet mask for this address 
	 */
	public IPv4Address getDefaultSubnetmask() {
		if (isAny()) {
			return DEFAULT_ANY_SUBNETMASK;
		} else if (isClassA()) {
			return DEFAULT_CLASS_A_SUBNETMASK;
		} else if (isClassB()) {
			return DEFAULT_CLASS_B_SUBNETMASK;
		} else if (isClassC()) {
			return DEFAULT_CLASS_C_SUBNETMASK;
		} else if (isClassD()) {
			return DEFAULT_CLASS_D_SUBNETMASK;
		} else {
			throw new IllegalArgumentException("Unknown address class");
		}
	}

	/**
	 * Gets the type of this address.
	 * This type is used by (e.g.) ARP.
	 */
	public int getType() {
		return EthernetConstants.ETH_P_IP;
	}
}