Package uk.co.westhawk.snmp.net

Class TCPSocket

java.lang.Object

uk.co.westhawk.snmp.net.TCPSocket

All Implemented Interfaces:

ContextSocketFace

public class TCPSocket
extends Object
implements ContextSocketFace

This is a wrapper class around the standard Socket. This sends packets over TCP.

This is part of what is called "Reliable SNMP". SNMP usually goes over UDP. That is why there is a retry mechanisme in SNMP. Sending SNMP over TCP will only work is your agent listens on TCP. See RFC 3430

When listening for incoming packets, the Socket, that is created when accepting an incoming connection, is closed at the end. Because of this, it is NOT possible to send a response back over the same connection.

Since:

4_14

Version:

$Revision: 1.8 $ $Date: 2009/03/05 15:56:19 $

Author:

Birgit Arkesteijn

See Also:

• Socket

Constructor Summary

Constructors

Constructor	Description
TCPSocket()

Method Summary

Modifier and Type	Method	Description
void	close()	Closes this socket.
void	create(int port, String bindAddr)	Creates the socket.
void	create(String host, int port, String bindAddr)	Creates the socket.
String	getLocalSocketAddress()	Returns the address of the endpoint this socket is bound to, or null if it is not bound yet.
String	getReceivedFromHostAddress()	Returns the IP address of the (latest) host of the packet we received.
String	getRemoteSocketAddress()	Returns the address of the endpoint this socket is connected to, or null if it is unconnected.
String	getSendToHostAddress()	Returns the IP address of the host we sent the packet to.
StreamPortItem	receive(int maxRecvSize)	Receives a packet from this socket.
void	send(byte[] packet)	Sends a packet from this socket.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

TCPSocket

public TCPSocket()

Method Details

create

public void create(int port,
 String bindAddr)
            throws IOException

Description copied from interface: ContextSocketFace

Creates the socket. This socket is used when listening for incoming requests or traps. Use only one (1) of the two create methods.

Specified by:

create in interface ContextSocketFace

Parameters:

port - The local port number were we receive (listen for) packets

bindAddr - The local address the server will bind to when listening

Throws:

IOException

See Also:

• ContextSocketFace.create(String, int, String)

create

public void create(String host,
 int port,
 String bindAddr)
            throws IOException

Description copied from interface: ContextSocketFace

Creates the socket. This socket is used to send out our requests. Use only one (1) of the two create methods.

Specified by:

create in interface ContextSocketFace

Parameters:

host - The name of the host that is to receive our packets

port - The port number of the host

bindAddr - The local address the server will bind to when sending packets

Throws:

IOException

See Also:

• ContextSocketFace.create(int, String)

getReceivedFromHostAddress

public String getReceivedFromHostAddress()

Description copied from interface: ContextSocketFace

Returns the IP address of the (latest) host of the packet we received. Only applicable when anything has been received. When sending a request, this will in most cases be the same host where we sent the original packet to.

Specified by:

getReceivedFromHostAddress in interface ContextSocketFace

Returns:

The IP address, or null when the hostname cannot be determined

See Also:

• ContextSocketFace.getSendToHostAddress()

getSendToHostAddress

public String getSendToHostAddress()

Description copied from interface: ContextSocketFace

Returns the IP address of the host we sent the packet to. Only applicable when sending requests, not when (only) listening for incoming requests or traps.

Specified by:

getSendToHostAddress in interface ContextSocketFace

Returns:

The IP address, or null when the hostname cannot be determined

See Also:

• ContextSocketFace.getReceivedFromHostAddress()

getLocalSocketAddress

public String getLocalSocketAddress()

Description copied from interface: ContextSocketFace

Returns the address of the endpoint this socket is bound to, or null if it is not bound yet.

Specified by:

getLocalSocketAddress in interface ContextSocketFace

getRemoteSocketAddress

public String getRemoteSocketAddress()

Description copied from interface: ContextSocketFace

Returns the address of the endpoint this socket is connected to, or null if it is unconnected.

Specified by:

getRemoteSocketAddress in interface ContextSocketFace

receive

public StreamPortItem receive(int maxRecvSize)
                       throws IOException

Description copied from interface: ContextSocketFace

Receives a packet from this socket. The StreamPortItem object contains the host and port the packet came from.

Specified by:

receive in interface ContextSocketFace

Parameters:

maxRecvSize - the maximum number of bytes to receive

Returns:

the packet

Throws:

IOException

send

public void send(byte[] packet)
          throws IOException

Description copied from interface: ContextSocketFace

Sends a packet from this socket. It can throw an "java.io.IOException: Invalid argument" when the bind address is incorrect for some reason.

Specified by:

send in interface ContextSocketFace

Parameters:

packet - the packet

Throws:

IOException

close

public void close()

Description copied from interface: ContextSocketFace

Closes this socket.

Specified by:

close in interface ContextSocketFace