Interface SocketFactory
- All Known Implementing Classes:
SunProxy
An instance of this interface can be passed to methods that allocate sockets. In this way, the actual, underlying type of socket allocated can be replaced (for instance, with an SSL socket or an firewall-tunnelling socket), without the user of the socket having to explicitly be aware of the underlying implementation.
In some ways, this class is a replacement for the
SocketImplFactory
class. This class addresses the following
issues.
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A
SocketImplFactory
may be installed only once for the entire process, so different policies cannot be used concurrently and/or consectively. For instance, imagine a situation where the user wants one part of the program talking via SSL to some port on machine A and via standard sockets to some port on machine B. It is not possible to install separateSocketImplFactory
objects to allow both. -
The standard
Socket
class presumes a highly-connected network with the ability to resolve hostnames to IP addresses. The standardSocket
class always converts the hostname to an IP address before callingSocketImplFactory
. If the hostname does not have an IP address, then theSocketImplFactory
never gets a chance to intercept the host name and perform alternate routing based on the name. For instance, imagine that the user has implemented a firewall-tunnelling socket; the raw hostname must be passed to the firewall machine, which allows the socket to be established once some out-of-band credentials are supplied. But we could never get this far because the standardSocket
class would have already rejected the request since the IP address of the target machine was unknown.
- Version:
- 2.2
- Author:
- Colin Stevens (colin.stevens@sun.com)
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Field Summary
Fields -
Method Summary
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Field Details
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defaultFactory
The default socket factory. It just creates a standardSocket
to the specified host and port, and is exactly equivalent to callingnew Socket(host, port)
.
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Method Details
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newSocket
Creates a newSocket
that talks to the specified port on the named host.The implementation may choose any way it wants to provide a socket-like object (essentially any mechanism that supports bidirectional communication). The returned
Socket
(or subclass ofSocket
) might not be based on TCP/IP, or it might involve running a TCP/IP stack over some other protocol, or it might actually redirect all connections via some other proxy machine, etc.- Parameters:
host
- The host name.port
- The port number.- Returns:
- An object that provides socket-like communication.
- Throws:
IOException
- If there is some problem establishing the socket to the specified port on the named host.
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