Androin学习笔记二十五：InetAddress(示例,出错代码)_android inetaddress.java

java.net
类 InetAddress

java.lang.Object
  java.net.InetAddress

所有已实现的接口：

Serializable

直接已知子类：

Inet4Address, Inet6Address

---

public class InetAddress
    
    
     
     extends Object
    
    
    
    
     
     implements Serializable
    
    

The Internet Protocol (IP) address representation class. This class encapsulates an IP address and provides name and reverse name resolution functions. The address is stored in network order, but as a signed (rather than unsigned) integer.

从以下版本开始：

Android 1.0

另请参见：

序列化表格

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equals

public boolean equals(Object obj)

Compares this  InetAddress instance against the specified address in  obj. Two addresses are equal if their address byte arrays have the same length and if the bytes in the arrays are equal.

覆盖：

类  Object 中的  equals

参数：

obj - the object to be tested for equality.

返回：

true if both objects are equal,  false otherwise.

从以下版本开始：

Android 1.0

另请参见：

Object.hashCode()

---

getAddress

public byte[] getAddress()

Returns the IP address represented by this  InetAddress instance as a byte array. The elements are in network order (the highest order address byte is in the zeroth element).

返回：

the address in form of a byte array.

从以下版本开始：

Android 1.0

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getAllByName

public static InetAddress[] getAllByName(String host)
                                  throws UnknownHostException

Gets all IP addresses associated with the given  host identified by name or IP address in dot-notation. The IP address is resolved by the configured name service. If the host name is empty or  null an  UnknownHostException is thrown. If the host name is a dotted IP address string an array with the corresponding single  InetAddress is returned.

参数：

host - the host's name or IP to be resolved to an address.

返回：

the array of addresses associated with the specified host.

抛出：

UnknownHostException - if the address lookup fails.

从以下版本开始：

Android 1.0

---

getByName

public static InetAddress getByName(String host)
                             throws UnknownHostException

Returns the address of a host according to the given host string name  host. The host string may be either a machine name or a dotted string IP address. If the latter, the hostName field is determined upon demand.  host can be  null which means that an address of the loopback interface is returned.

参数：

host - the hostName to be resolved to an address or  null.

返回：

the  InetAddress instance representing the host.

抛出：

UnknownHostException - if the address lookup fails.

从以下版本开始：

Android 1.0

---

getHostAddress

public String getHostAddress()

Gets the textual representation of this IP address.

返回：

the textual representation of this host address in form of a dotted string.

从以下版本开始：

Android 1.0

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getHostName

public String getHostName()

Gets the host name of this IP address. If the IP address could not be resolved, the textual representation in a dotted-quad-notation is returned.

返回：

the corresponding string name of this IP address.

从以下版本开始：

Android 1.0

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getCanonicalHostName

public String getCanonicalHostName()

Gets the fully qualified domain name for the host associated with this IP address. If a security manager is set, it is checked if the method caller is allowed to get the hostname. Otherwise, the textual representation in a dotted-quad-notation is returned.

返回：

the fully qualified domain name of this IP address.

从以下版本开始：

Android 1.0

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getLocalHost

public static InetAddress getLocalHost()
                                throws UnknownHostException

Gets the local host address if the security policy allows this. Otherwise, gets the loopback address which allows this machine to be contacted.

The current implementation returns always the loopback address.

返回：

the  InetAddress representing the local host.

抛出：

UnknownHostException - if the address lookup fails.

从以下版本开始：

Android 1.0

---

hashCode

public int hashCode()

Gets the hashcode of the represented IP address.

覆盖：

类  Object 中的  hashCode

返回：

the appropriate hashcode value.

从以下版本开始：

Android 1.0

另请参见：

Object.equals(java.lang.Object)

---

isMulticastAddress

public boolean isMulticastAddress()

Returns whether this address is an IP multicast address or not.

返回：

true if this address is in the multicast group,  false otherwise.

从以下版本开始：

Android 1.0

---

toString

public String toString()

Returns a string containing a concise, human-readable description of this IP address.

覆盖：

类  Object 中的  toString

返回：

the description, as host/address.

从以下版本开始：

Android 1.0

---

isLoopbackAddress

public boolean isLoopbackAddress()

Returns whether this address is a loopback address or not. This implementation returns always  false. Valid IPv4 loopback addresses are 127.d.d.d The only valid IPv6 loopback address is ::1.

返回：

true if this instance represents a loopback address,  false otherwise.

从以下版本开始：

Android 1.0

---

isLinkLocalAddress

public boolean isLinkLocalAddress()

Returns whether this address is a link-local address or not. This implementation returns always  false.

Valid IPv6 link-local addresses are FE80::0 through to FEBF:FFFF:FFFF:FFFF:FFFF:FFFF:FFFF:FFFF.

There are no valid IPv4 link-local addresses.

返回：

true if this instance represents a link-local address,  false otherwise.

从以下版本开始：

Android 1.0

---

isSiteLocalAddress

public boolean isSiteLocalAddress()

Returns whether this address is a site-local address or not. This implementation returns always  false.

Valid IPv6 site-local addresses are FEC0::0 through to FEFF:FFFF:FFFF:FFFF:FFFF:FFFF:FFFF:FFFF.

There are no valid IPv4 site-local addresses.

返回：

true if this instance represents a site-local address,  false otherwise.

从以下版本开始：

Android 1.0

---

isMCGlobal

public boolean isMCGlobal()

Returns whether this address is a global multicast address or not. This implementation returns always  false.

Valid IPv6 link-global multicast addresses are FFxE:/112 where x is a set of flags, and the additional 112 bits make up the global multicast address space.

Valid IPv4 global multicast addresses are between: 224.0.1.0 to 238.255.255.255.

返回：

true if this instance represents a global multicast address,  false otherwise.

从以下版本开始：

Android 1.0

---

isMCNodeLocal

public boolean isMCNodeLocal()

Returns whether this address is a node-local multicast address or not. This implementation returns always  false.

Valid IPv6 node-local multicast addresses are FFx1:/112 where x is a set of flags, and the additional 112 bits make up the node-local multicast address space.

There are no valid IPv4 node-local multicast addresses.

返回：

true if this instance represents a node-local multicast address,  false otherwise.

从以下版本开始：

Android 1.0

---

isMCLinkLocal

public boolean isMCLinkLocal()

Returns whether this address is a link-local multicast address or not. This implementation returns always  false.

Valid IPv6 link-local multicast addresses are FFx2:/112 where x is a set of flags, and the additional 112 bits make up the link-local multicast address space.

Valid IPv4 link-local addresses are between: 224.0.0.0 to 224.0.0.255

返回：

true if this instance represents a link-local multicast address,  false otherwise.

从以下版本开始：

Android 1.0

---

isMCSiteLocal

public boolean isMCSiteLocal()

Returns whether this address is a site-local multicast address or not. This implementation returns always  false.

Valid IPv6 site-local multicast addresses are FFx5:/112 where x is a set of flags, and the additional 112 bits make up the site-local multicast address space.

Valid IPv4 site-local addresses are between: 239.252.0.0 to 239.255.255.255

返回：

true if this instance represents a site-local multicast address,  false otherwise.

从以下版本开始：

Android 1.0

---

isMCOrgLocal

public boolean isMCOrgLocal()

Returns whether this address is a organization-local multicast address or not. This implementation returns always  false.

Valid IPv6 organization-local multicast addresses are FFx8:/112 where x is a set of flags, and the additional 112 bits make up the organization-local multicast address space.

Valid IPv4 organization-local addresses are between: 239.192.0.0 to 239.251.255.255

返回：

true if this instance represents a organization-local multicast address,  false otherwise.

从以下版本开始：

Android 1.0

---

isAnyLocalAddress

public boolean isAnyLocalAddress()

Returns whether this is a wildcard address or not. This implementation returns always  false.

返回：

true if this instance represents a wildcard address,  false otherwise.

从以下版本开始：

Android 1.0

---

isReachable

public boolean isReachable(int timeout)
                    throws IOException

Tries to reach this  InetAddress. This method first tries to use ICMP  (ICMP ECHO REQUEST). When first step fails, a TCP connection on port 7 (Echo) of the remote host is established.

参数：

timeout - timeout in milliseconds before the test fails if no connection could be established.

返回：

true if this address is reachable,  false otherwise.

抛出：

IOException - if an error occurs during an I/O operation.

IllegalArgumentException - if timeout is less than zero.

从以下版本开始：

Android 1.0

---

isReachable

public boolean isReachable(NetworkInterface netif,
                           int ttl,
                           int timeout)
                    throws IOException

Tries to reach this  InetAddress. This method first tries to use ICMP  (ICMP ECHO REQUEST). When first step fails, a TCP connection on port 7 (Echo) of the remote host is established.

参数：

netif - the network interface on which to connection should be established.

ttl - the maximum count of hops (time-to-live).

timeout - timeout in milliseconds before the test fails if no connection could be established.

返回：

true if this address is reachable,  false otherwise.

抛出：

IOException - if an error occurs during an I/O operation.

IllegalArgumentException - if ttl or timeout is less than zero.

从以下版本开始：

Android 1.0

---

getByAddress

public static InetAddress getByAddress(byte[] ipAddress)
                                throws UnknownHostException

Returns the  InetAddress corresponding to the array of bytes. In the case of an IPv4 address there must be exactly 4 bytes and for IPv6 exactly 16 bytes. If not, an UnknownHostException is thrown.

The IP address is not validated by a name service.

The high order byte is ipAddress[0].

参数：

ipAddress - is either a 4 (IPv4) or 16 (IPv6) byte long array.

返回：

an  InetAddress instance representing the given IP address  ipAddress.

抛出：

UnknownHostException - if the given byte array has no valid length.

从以下版本开始：

Android 1.0

---

getByAddress

public static InetAddress getByAddress(String hostName,
                                       byte[] ipAddress)
                                throws UnknownHostException

Returns the  InetAddress corresponding to the array of bytes, andthe given hostname. In the case of an IPv4 address there must be exactly4 bytes and for IPv6 exactly 16 bytes. If not, an  UnknownHostException will be thrown.

The host name and IP address are not validated.

The hostname either be a machine alias or a valid IPv6 or IPv4 addressformat.

The high order byte is ipAddress[0].

参数：

hostName - the string representation of hostname or IP address.

ipAddress - either a 4 (IPv4) or 16 (IPv6) byte long array.

返回：

an  InetAddress instance representing the given IP addressand hostname.

抛出：

UnknownHostException - if the given byte array has no valid length.

从以下版本开始：

Android 1.0