JDK8/Java8源码在线阅读
/*
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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*/
package java.net;
import java.io.ObjectStreamException;
/**
* This class represents an Internet Protocol version 4 (IPv4) address.
* Defined by <a href="http://www.ietf.org/rfc/rfc790.txt">
* <i>RFC 790: Assigned Numbers</i></a>,
* <a href="http://www.ietf.org/rfc/rfc1918.txt">
* <i>RFC 1918: Address Allocation for Private Internets</i></a>,
* and <a href="http://www.ietf.org/rfc/rfc2365.txt"><i>RFC 2365:
* Administratively Scoped IP Multicast</i></a>
*
* <h3> <A NAME="format">Textual representation of IP addresses</a> </h3>
*
* Textual representation of IPv4 address used as input to methods
* takes one of the following forms:
*
* <blockquote><table cellpadding=0 cellspacing=0 summary="layout">
* <tr><td>{@code d.d.d.d}</td></tr>
* <tr><td>{@code d.d.d}</td></tr>
* <tr><td>{@code d.d}</td></tr>
* <tr><td>{@code d}</td></tr>
* </table></blockquote>
*
* <p> When four parts are specified, each is interpreted as a byte of
* data and assigned, from left to right, to the four bytes of an IPv4
* address.
* <p> When a three part address is specified, the last part is
* interpreted as a 16-bit quantity and placed in the right most two
* bytes of the network address. This makes the three part address
* format convenient for specifying Class B net- work addresses as
* 128.net.host.
*
* <p> When a two part address is supplied, the last part is
* interpreted as a 24-bit quantity and placed in the right most three
* bytes of the network address. This makes the two part address
* format convenient for specifying Class A network addresses as
* net.host.
*
* <p> When only one part is given, the value is stored directly in
* the network address without any byte rearrangement.
*
* <p> For methods that return a textual representation as output
* value, the first form, i.e. a dotted-quad string, is used.
*
* <h4> The Scope of a Multicast Address </h4>
*
* Historically the IPv4 TTL field in the IP header has doubled as a
* multicast scope field: a TTL of 0 means node-local, 1 means
* link-local, up through 32 means site-local, up through 64 means
* region-local, up through 128 means continent-local, and up through
* 255 are global. However, the administrative scoping is preferred.
* Please refer to <a href="http://www.ietf.org/rfc/rfc2365.txt">
* <i>RFC 2365: Administratively Scoped IP Multicast</i></a>
* @since 1.4
*/
public final
class Inet4Address extends InetAddress {
final static int INADDRSZ = 4;
/** use serialVersionUID from InetAddress, but Inet4Address instance
* is always replaced by an InetAddress instance before being
* serialized */
private static final long serialVersionUID = 3286316764910316507L;
/*
* Perform initializations.
*/
static {
init();
}
Inet4Address() {
super();
holder().hostName = null;
holder().address = 0;
holder().family = IPv4;
}
Inet4Address(String hostName, byte addr[]) {
holder().hostName = hostName;
holder().family = IPv4;
if (addr != null) {
if (addr.length == INADDRSZ) {
int address = addr[3] & 0xFF;
address |= ((addr[2] << 8) & 0xFF00);
address |= ((addr[1] << 16) & 0xFF0000);
address |= ((addr[0] << 24) & 0xFF000000);
holder().address = address;
}
}
}
Inet4Address(String hostName, int address) {
holder().hostName = hostName;
holder().family = IPv4;
holder().address = address;
}
/**
* Replaces the object to be serialized with an InetAddress object.
*
* @return the alternate object to be serialized.
*
* @throws ObjectStreamException if a new object replacing this
* object could not be created
*/
private Object writeReplace() throws ObjectStreamException {
// will replace the to be serialized 'this' object
InetAddress inet = new InetAddress();
inet.holder().hostName = holder().getHostName();
inet.holder().address = holder().getAddress();
/**
* Prior to 1.4 an InetAddress was created with a family
* based on the platform AF_INET value (usually 2).
* For compatibility reasons we must therefore write the
* the InetAddress with this family.
*/
inet.holder().family = 2;
return inet;
}
/**
* Utility routine to check if the InetAddress is an
* IP multicast address. IP multicast address is a Class D
* address i.e first four bits of the address are 1110.
* @return a {@code boolean} indicating if the InetAddress is
* an IP multicast address
* @since JDK1.1
*/
public boolean isMulticastAddress() {
return ((holder().getAddress() & 0xf0000000) == 0xe0000000);
}
/**
* Utility routine to check if the InetAddress in a wildcard address.
* @return a {@code boolean} indicating if the Inetaddress is
* a wildcard address.
* @since 1.4
*/
public boolean isAnyLocalAddress() {
return holder().getAddress() == 0;
}
/**
* Utility routine to check if the InetAddress is a loopback address.
*
* @return a {@code boolean} indicating if the InetAddress is
* a loopback address; or false otherwise.
* @since 1.4
*/
public boolean isLoopbackAddress() {
/* 127.x.x.x */
byte[] byteAddr = getAddress();
return byteAddr[0] == 127;
}
/**
* Utility routine to check if the InetAddress is an link local address.
*
* @return a {@code boolean} indicating if the InetAddress is
* a link local address; or false if address is not a link local unicast address.
* @since 1.4
*/
public boolean isLinkLocalAddress() {
// link-local unicast in IPv4 (169.254.0.0/16)
// defined in "Documenting Special Use IPv4 Address Blocks
// that have been Registered with IANA" by Bill Manning
// draft-manning-dsua-06.txt
int address = holder().getAddress();
return (((address >>> 24) & 0xFF) == 169)
&& (((address >>> 16) & 0xFF) == 254);
}
/**
* Utility routine to check if the InetAddress is a site local address.
*
* @return a {@code boolean} indicating if the InetAddress is
* a site local address; or false if address is not a site local unicast address.
* @since 1.4
*/
public boolean isSiteLocalAddress() {
// refer to RFC 1918
// 10/8 prefix
// 172.16/12 prefix
// 192.168/16 prefix
int address = holder().getAddress();
return (((address >>> 24) & 0xFF) == 10)
|| ((((address >>> 24) & 0xFF) == 172)
&& (((address >>> 16) & 0xF0) == 16))
|| ((((address >>> 24) & 0xFF) == 192)
&& (((address >>> 16) & 0xFF) == 168));
}
/**
* Utility routine to check if the multicast address has global scope.
*
* @return a {@code boolean} indicating if the address has
* is a multicast address of global scope, false if it is not
* of global scope or it is not a multicast address
* @since 1.4
*/
public boolean isMCGlobal() {
// 224.0.1.0 to 238.255.255.255
byte[] byteAddr = getAddress();
return ((byteAddr[0] & 0xff) >= 224 && (byteAddr[0] & 0xff) <= 238 ) &&
!((byteAddr[0] & 0xff) == 224 && byteAddr[1] == 0 &&
byteAddr[2] == 0);
}
/**
* Utility routine to check if the multicast address has node scope.
*
* @return a {@code boolean} indicating if the address has
* is a multicast address of node-local scope, false if it is not
* of node-local scope or it is not a multicast address
* @since 1.4
*/
public boolean isMCNodeLocal() {
// unless ttl == 0
return false;
}
/**
* Utility routine to check if the multicast address has link scope.
*
* @return a {@code boolean} indicating if the address has
* is a multicast address of link-local scope, false if it is not
* of link-local scope or it is not a multicast address
* @since 1.4
*/
public boolean isMCLinkLocal() {
// 224.0.0/24 prefix and ttl == 1
int address = holder().getAddress();
return (((address >>> 24) & 0xFF) == 224)
&& (((address >>> 16) & 0xFF) == 0)
&& (((address >>> 8) & 0xFF) == 0);
}
/**
* Utility routine to check if the multicast address has site scope.
*
* @return a {@code boolean} indicating if the address has
* is a multicast address of site-local scope, false if it is not
* of site-local scope or it is not a multicast address
* @since 1.4
*/
public boolean isMCSiteLocal() {
// 239.255/16 prefix or ttl < 32
int address = holder().getAddress();
return (((address >>> 24) & 0xFF) == 239)
&& (((address >>> 16) & 0xFF) == 255);
}
/**
* Utility routine to check if the multicast address has organization scope.
*
* @return a {@code boolean} indicating if the address has
* is a multicast address of organization-local scope,
* false if it is not of organization-local scope
* or it is not a multicast address
* @since 1.4
*/
public boolean isMCOrgLocal() {
// 239.192 - 239.195
int address = holder().getAddress();
return (((address >>> 24) & 0xFF) == 239)
&& (((address >>> 16) & 0xFF) >= 192)
&& (((address >>> 16) & 0xFF) <= 195);
}
/**
* Returns the raw IP address of this {@code InetAddress}
* object. The result is in network byte order: the highest order
* byte of the address is in {@code getAddress()[0]}.
*
* @return the raw IP address of this object.
*/
public byte[] getAddress() {
int address = holder().getAddress();
byte[] addr = new byte[INADDRSZ];
addr[0] = (byte) ((address >>> 24) & 0xFF);
addr[1] = (byte) ((address >>> 16) & 0xFF);
addr[2] = (byte) ((address >>> 8) & 0xFF);
addr[3] = (byte) (address & 0xFF);
return addr;
}
/**
* Returns the IP address string in textual presentation form.
*
* @return the raw IP address in a string format.
* @since JDK1.0.2
*/
public String getHostAddress() {
return numericToTextFormat(getAddress());
}
/**
* Returns a hashcode for this IP address.
*
* @return a hash code value for this IP address.
*/
public int hashCode() {
return holder().getAddress();
}
/**
* Compares this object against the specified object.
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