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java.lang.Object | +--ipworks.Ipport
The IPPort class facilitates TCP/IP communications by providing an easy interface to Winsock functions. It allows a client application to communicate with a server using stream sockets.
Our main goal in designing IPPort was ease of use. The class has a minimum of properties and five events: Connected , DataIn , Disconnected , ReadyToSend , and Error . The events are relatively self-explanatory.
The connection is attempted by setting the Connected property to True, and then waiting for the Connected event. The destination is defined by setting RemoteHost and RemotePort . Data is sent by assigning the data string to the DataToSend property.
To disconnect, you just set the Connected property to False. The Linger property controls how the connection is terminated.
The operation of the class is almost completely asynchronous. All the calls except the ones that deal with domain name resolution, operate through Windows messages (no blocking calls). The gain in performance is considerable when compared to using blocking calls.
Constructor Summary | |
Ipport()
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Method Summary | |
void |
addIpportEventListener(IpportEventListener l)
|
void |
fireConnected(int statusCode,
java.lang.String description)
Fired immediately after a connection completes (or fails). |
void |
fireDataIn(byte[] text,
boolean EOL)
Fired when data (complete lines) comes in. |
void |
fireDisconnected(int statusCode,
java.lang.String description)
Fired when a connection is closed. |
void |
fireError(int errorCode,
java.lang.String description)
Information about errors during data delivery. |
void |
fireReadyToSend()
Fired when IPPort is ready to send data. |
int |
getBytesSent()
The number of bytes actually sent after an assignment to DataToSend . |
byte[] |
getEOL()
Used to break the incoming data stream into chunks separated by EOL. |
int |
getInBufferSize()
The size in bytes of the incoming queue of the socket. |
java.lang.String |
getLocalHost()
The name of the local host. |
int |
getLocalPort()
The TCP port in the local host where IPPort binds. |
int |
getMaxLineLength()
The maximum amount of data to accumulate when no EOL is found. |
int |
getOutBufferSize()
The size in bytes of the outgoing queue of the socket. |
java.lang.String |
getRemoteHost()
The address of the remote host. |
int |
getRemotePort()
The TCP port in the remote host. |
boolean |
isAcceptData()
Enables or disables data reception (the DataIn event). |
boolean |
isConnected()
Triggers a connection or disconnection. |
boolean |
isKeepAlive()
When True, KEEPALIVE packets are enabled (for long connections). |
boolean |
isLinger()
When set to True, connections are terminated gracefully. |
void |
removeIpportEventListener(IpportEventListener l)
|
void |
setAcceptData(boolean acceptData)
Enables or disables data reception (the DataIn event). |
void |
setConnected(boolean connected)
Triggers a connection or disconnection. |
void |
setDataToSend(byte[] dataToSend)
A string of data to be sent to the remote host. |
void |
setEOL(byte[] EOL)
Used to break the incoming data stream into chunks separated by EOL. |
void |
setInBufferSize(int inBufferSize)
The size in bytes of the incoming queue of the socket. |
void |
setKeepAlive(boolean keepAlive)
When True, KEEPALIVE packets are enabled (for long connections). |
void |
setLinger(boolean linger)
When set to True, connections are terminated gracefully. |
void |
setLocalPort(int localPort)
The TCP port in the local host where IPPort binds. |
void |
setMaxLineLength(int maxLineLength)
The maximum amount of data to accumulate when no EOL is found. |
void |
setOutBufferSize(int outBufferSize)
The size in bytes of the outgoing queue of the socket. |
void |
setRemoteHost(java.lang.String remoteHost)
The address of the remote host. |
void |
setRemotePort(int remotePort)
The TCP port in the remote host. |
Methods inherited from class java.lang.Object |
clone,
equals,
finalize,
getClass,
hashCode,
notify,
notifyAll,
toString,
wait,
wait,
wait |
Constructor Detail |
public Ipport()
Method Detail |
public boolean isAcceptData()
public void setAcceptData(boolean acceptData) throws IPWorksException
public int getBytesSent()
public boolean isConnected()
Setting Connected to False closes the connection. How and when the connection is closed is controlled by the Linger property.
public void setConnected(boolean connected) throws IPWorksException
Setting Connected to False closes the connection. How and when the connection is closed is controlled by the Linger property.
public void setDataToSend(byte[] dataToSend) throws IPWorksException
If you are sending data to the remote host faster than it can process it, or faster than the network's bandwidth allows, the outgoing queue might fill up. When this happens, DataToSend The BytesSent property shows how many bytes were sent (if any). If 0 bytes were sent, then you can wait for the ReadyToSend event before attempting to send data again. (However, please note that ReadyToSend is not fired when part of the data is successfully sent).
public byte[] getEOL()
The EOL property is especially useful with ASCII files. Setting it to "\\n" (newline) enables splitting of the incoming ASCII text stream into lines. In this case, one event is fired for each line received (as well as in packet boundaries). The "\\n" characters are discarded.
The EOL property is a byte array string. In particular, this means that it can be more than one character long, and it can contain NULL ('\\0') characters as well.
public void setEOL(byte[] EOL) throws IPWorksException
The EOL property is especially useful with ASCII files. Setting it to "\\n" (newline) enables splitting of the incoming ASCII text stream into lines. In this case, one event is fired for each line received (as well as in packet boundaries). The "\\n" characters are discarded.
The EOL property is a byte array string. In particular, this means that it can be more than one character long, and it can contain NULL ('\\0') characters as well.
public int getInBufferSize()
Some TCP/IP implementations do not support variable buffer sizes. If that is the case, when a new connection is attempted the InBufferSize property reverts to its defined size. The same happens if you attempt to make it too large or too small.
public void setInBufferSize(int inBufferSize) throws IPWorksException
Some TCP/IP implementations do not support variable buffer sizes. If that is the case, when a new connection is attempted the InBufferSize property reverts to its defined size. The same happens if you attempt to make it too large or too small.
public boolean isKeepAlive()
Please note that Winsock implementations are not required to support SO_KEEPALIVE.
public void setKeepAlive(boolean keepAlive) throws IPWorksException
Please note that Winsock implementations are not required to support SO_KEEPALIVE.
public boolean isLinger()
The default behavior (which is also the default mode for Winsock stream sockets) might result in an indefinite delay in closing the connection. Although the class returns control immediately, Winsock might indefinitely hold system resources until all pending data are sent (even after your application closes). This means that valuable system resources might be wasted.
Setting Linger to False forces an immediate disconnection. If you know that the other side has received all the data you had sent (by a client acknowledgment, for example), setting Linger to False might be the appropriate course of action.
public void setLinger(boolean linger) throws IPWorksException
The default behavior (which is also the default mode for Winsock stream sockets) might result in an indefinite delay in closing the connection. Although the class returns control immediately, Winsock might indefinitely hold system resources until all pending data are sent (even after your application closes). This means that valuable system resources might be wasted.
Setting Linger to False forces an immediate disconnection. If you know that the other side has received all the data you had sent (by a client acknowledgment, for example), setting Linger to False might be the appropriate course of action.
public java.lang.String getLocalHost()
If the class is connected, the LocalHost property shows the IP address of the interface through which the connection is made in internet dotted format (aaa.bbb.ccc.ddd). In most cases, this is the address of the local host, except for multihomed hosts (machines with more than one IP interface).
public int getLocalPort()
Setting it to 0 (default) enables Winsock to choose a port at random. The chosen port will be shown by the LocalPort property after the connection is established.
LocalPort cannot be changed once a connection is made. Any attempt to set the LocalPort property when a connection is active will generate an error.
The LocalPort property is useful when trying to connect to services that require a trusted port in the client side. An example is the remote shell (rsh) service in UNIX systems.
public void setLocalPort(int localPort) throws IPWorksException
Setting it to 0 (default) enables Winsock to choose a port at random. The chosen port will be shown by the LocalPort property after the connection is established.
LocalPort cannot be changed once a connection is made. Any attempt to set the LocalPort property when a connection is active will generate an error.
The LocalPort property is useful when trying to connect to services that require a trusted port in the client side. An example is the remote shell (rsh) service in UNIX systems.
public int getMaxLineLength()
If an EOL string is found in the input stream before MaxLineLength characters are received, the DataIn event is fired with the EOL parameter set to True, and the buffer is reset.
If no EOL is found, and MaxLineLength characters are accumulated in the buffer, the DataIn event is fired with the EOL parameter set to False, and the buffer is reset.
The minimum value for MaxLineLength is 256.
public void setMaxLineLength(int maxLineLength) throws IPWorksException
If an EOL string is found in the input stream before MaxLineLength characters are received, the DataIn event is fired with the EOL parameter set to True, and the buffer is reset.
If no EOL is found, and MaxLineLength characters are accumulated in the buffer, the DataIn event is fired with the EOL parameter set to False, and the buffer is reset.
The minimum value for MaxLineLength is 256.
public int getOutBufferSize()
Some TCP/IP implementations do not support variable buffer sizes. If that is the case, when a new connection is attempted the OutBufferSize property reverts to its defined size. The same happens if you attempt to make it too large or too small.
public void setOutBufferSize(int outBufferSize) throws IPWorksException
Some TCP/IP implementations do not support variable buffer sizes. If that is the case, when a new connection is attempted the OutBufferSize property reverts to its defined size. The same happens if you attempt to make it too large or too small.
public java.lang.String getRemoteHost()
If the RemoteHost property is set to a Domain Name, a DNS request is initiated, and upon successful termination of the request, the RemoteHost property is set to the corresponding address. If the search is not successful, an error is returned.
public void setRemoteHost(java.lang.String remoteHost) throws IPWorksException
If the RemoteHost property is set to a Domain Name, a DNS request is initiated, and upon successful termination of the request, the RemoteHost property is set to the corresponding address. If the search is not successful, an error is returned.
public int getRemotePort()
A valid port number (a value between 1 and 65535) is required for the connection to take place. The property must be set before a connection is attempted and cannot be changed once a connection is established. Any attempt to change the RemotePort while connected will fail with an error.
public void setRemotePort(int remotePort) throws IPWorksException
A valid port number (a value between 1 and 65535) is required for the connection to take place. The property must be set before a connection is attempted and cannot be changed once a connection is established. Any attempt to change the RemotePort while connected will fail with an error.
public void fireConnected(int statusCode, java.lang.String description)
IpportConnectedEvent
public void fireDataIn(byte[] text, boolean EOL)
IpportDataInEvent
public void fireDisconnected(int statusCode, java.lang.String description)
IpportDisconnectedEvent
public void fireError(int errorCode, java.lang.String description)
IpportErrorEvent
public void fireReadyToSend()
IpportReadyToSendEvent
public void addIpportEventListener(IpportEventListener l) throws java.util.TooManyListenersException
public void removeIpportEventListener(IpportEventListener l)
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