ipworks
Class Udpport

java.lang.Object
  |
  +--ipworks.Udpport

public class Udpport

extends java.lang.Object

The UDPPort bean is used to facilitate UDP (datagram) communications. It can act both as a client and a server and communicate with any number of hosts simultaneously, as well as generate and receive broadcast packets.

The interface of the bean is similar to the interface of IPPort, only much simpler. The bean is activated/deactivated through the Active property. This property enables or disables sends or receives. The data can be sent in the same way as IPPort, using the Send method and specifying the text to send. This is identical to assigning data to the DataToSend property. The destination is specified using the RemoteHost and RemotePort properties. Inbound data is received through the DataIn event.

If theUseConnectionconfig setting is set to True, then a local association is created with the remote host. Otherwise, the bean can receive datagrams (packets) from any host, and send datagrams to any host. Packets can be broadcasted on the local net by setting the destination ( RemoteHost ) to 255.255.255.255.

The operation of the bean is almost completely asynchronous. All 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

Udpport()

Method Summary

void	addUdpportEventListener(ipworks.UdpportEventListener l)
java.lang.String	config(java.lang.String configurationString) Sets or retrieves a beanconfiguration setting.
void	doEvents() Processes events from the internal message queue.
java.lang.String	getLocalHost() The name of the local host or user-assigned IP interface through which connections are initiated or accepted.
int	getLocalPort() The UDP port in the local host where UDPPort binds.
java.lang.String	getRemoteHost() The address of the remote host.
int	getRemotePort() The UDP port in the remote host.
int	getTimeToLive() The maximum number of subnets that a datagram can traverse.
boolean	isAcceptData() Enables or disables data reception (the DataIn event).
boolean	isActive() Enables or disables sending and receiving of data.
boolean	isDontRoute() If set to True, forces the socket to send data directly to interface (no routing).
void	removeUdpportEventListener(ipworks.UdpportEventListener l)
void	send(byte[] text) Send data to the remote host.
void	setAcceptData(boolean acceptData) Enables or disables data reception (the DataIn event).
void	setActive(boolean active) Enables or disables sending and receiving of data.
void	setDataToSend(byte[] dataToSend) A string of data to be sent to the remote host.
void	setDontRoute(boolean dontRoute) If set to True, forces the socket to send data directly to interface (no routing).
void	setLocalHost(java.lang.String localHost) The name of the local host or user-assigned IP interface through which connections are initiated or accepted.
void	setLocalPort(int localPort) The UDP port in the local host where UDPPort binds.
void	setRemoteHost(java.lang.String remoteHost) The address of the remote host.
void	setRemotePort(int remotePort) The UDP port in the remote host.
void	setTimeToLive(int timeToLive) The maximum number of subnets that a datagram can traverse.

Methods inherited from class java.lang.Object

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

Constructor Detail

Udpport

public Udpport()

Method Detail

isAcceptData

public boolean isAcceptData()

Enables or disables data reception (the DataIn event).

Setting the property to False, temporarily disables data reception (and the DataIn event). Setting the property to True, re-enables data reception.

setAcceptData

public void setAcceptData(boolean acceptData)
                   throws IPWorksException

Enables or disables data reception (the DataIn event).

Setting the property to False, temporarily disables data reception (and the DataIn event). Setting the property to True, re-enables data reception.

IPWorksException

isActive

public boolean isActive()

Enables or disables sending and receiving of data.

Setting the Active property to True makes the bean create a communication endpoint (socket) which can be used for sending and receiving UDP datagrams. Setting it to False destroys the socket and disables data communications.

IfUseConnectionis set to True, then a local association (connection) to the remote host and port is also created.

setActive

public void setActive(boolean active)
               throws IPWorksException

Enables or disables sending and receiving of data.

Setting the Active property to True makes the bean create a communication endpoint (socket) which can be used for sending and receiving UDP datagrams. Setting it to False destroys the socket and disables data communications.

IfUseConnectionis set to True, then a local association (connection) to the remote host and port is also created.

IPWorksException

setDataToSend

public void setDataToSend(byte[] dataToSend)
                   throws IPWorksException

A string of data to be sent to the remote host. Write-only property.

Assigning a string to the DataToSend property makes the bean send the string to the remote host. The Send method provides similar functionality.

Attempts to send the string assigned to DataToSend as a complete message. If system buffers are full, or the message cannot be delivered for any other reason, an error is fired, and no portion of the message is sent. This is different from TCP where portions of the messages can be sent. UDP sends either a complete message or nothing at all.

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 fails with exception 10035: "[10035] Operation would block" (WSAEWOULDBLOCK). You can check this error, and then try to send the data again.

Example (Send Data)

 UDPPortControl.LocalPort = 8765 
 UDPPortControl.RemotePort = 8765 
 UDPPortControl.RemoteHost = "HostNameOrIPAddress"
 UDPPortControl.Active = True
 UDPPortControl.DataToSend = "Hello!" 

IPWorksException

isDontRoute

public boolean isDontRoute()

If set to True, forces the socket to send data directly to interface (no routing).

Normally IP sockets send packets of data through routers and gateways until they reach the final destination. If the DontRoute flag is set to True, then data will be delivered on the local subnet only.

setDontRoute

public void setDontRoute(boolean dontRoute)
                  throws IPWorksException

If set to True, forces the socket to send data directly to interface (no routing).

Normally IP sockets send packets of data through routers and gateways until they reach the final destination. If the DontRoute flag is set to True, then data will be delivered on the local subnet only.

IPWorksException

getLocalHost

public java.lang.String getLocalHost()

The name of the local host or user-assigned IP interface through which connections are initiated or accepted.

The LocalHost property contains the name of the local host as obtained by the gethostname() system call, or if the user has assigned an IP address, the value of that address.

In multihomed hosts (machines with more than one IP interface) setting LocalHost to the value of an interface will make the bean initiate connections (or accept in the case of server beans) only through that interface.

If the bean 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).

NOTE: LocalHost is not persistent. You must always set it in code, and never in the property window.

setLocalHost

public void setLocalHost(java.lang.String localHost)
                  throws IPWorksException

The name of the local host or user-assigned IP interface through which connections are initiated or accepted.

The LocalHost property contains the name of the local host as obtained by the gethostname() system call, or if the user has assigned an IP address, the value of that address.

In multihomed hosts (machines with more than one IP interface) setting LocalHost to the value of an interface will make the bean initiate connections (or accept in the case of server beans) only through that interface.

If the bean 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).

NOTE: LocalHost is not persistent. You must always set it in code, and never in the property window.

IPWorksException

getLocalPort

public int getLocalPort()

The UDP port in the local host where UDPPort binds.

The LocalPort property must be set before UDPPort is activated ( Active is set to True). It instructs the bean to bind to a specific port (or communication endpoint) in the local machine.

Setting it to 0 (default) enables the TCP/IP stack 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 the bean is Active . Any attempt to set the LocalPort property when the bean 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.

setLocalPort

public void setLocalPort(int localPort)
                  throws IPWorksException

The UDP port in the local host where UDPPort binds.

The LocalPort property must be set before UDPPort is activated ( Active is set to True). It instructs the bean to bind to a specific port (or communication endpoint) in the local machine.

Setting it to 0 (default) enables the TCP/IP stack 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 the bean is Active . Any attempt to set the LocalPort property when the bean 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.

IPWorksException

getRemoteHost

public java.lang.String getRemoteHost()

The address of the remote host. Domain names are resolved to IP addresses.

The RemoteHost property specifies the IP address (IP number in dotted internet format) or Domain Name of the remote host.

If RemoteHost is set to 255.255.255.255, the bean broadcasts data on the local subnet.

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.

IfUseConnectionis set to True, the RemoteHost must be set before the bean is activated ( Active is set to True).

setRemoteHost

public void setRemoteHost(java.lang.String remoteHost)
                   throws IPWorksException

The address of the remote host. Domain names are resolved to IP addresses.

The RemoteHost property specifies the IP address (IP number in dotted internet format) or Domain Name of the remote host.

If RemoteHost is set to 255.255.255.255, the bean broadcasts data on the local subnet.

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.

IfUseConnectionis set to True, the RemoteHost must be set before the bean is activated ( Active is set to True).

IPWorksException

getRemotePort

public int getRemotePort()

The UDP port in the remote host.

The RemotePort is the UDP port on the RemoteHost to send UDP datagrams to.

A valid port number (a value between 1 and 65535) is required.

IfUseConnectionis set to True, the RemotePort must be set before the bean is activated ( Active is set to True).

setRemotePort

public void setRemotePort(int remotePort)
                   throws IPWorksException

The UDP port in the remote host.

The RemotePort is the UDP port on the RemoteHost to send UDP datagrams to.

A valid port number (a value between 1 and 65535) is required.

IfUseConnectionis set to True, the RemotePort must be set before the bean is activated ( Active is set to True).

IPWorksException

getTimeToLive

public int getTimeToLive()

The maximum number of subnets that a datagram can traverse.

The default value for this property is 0, which tells the bean to use the default TTL value of the underlying TCP/IP subsystem. Depending on the application, you can specify a value between 1 and 255.

setTimeToLive

public void setTimeToLive(int timeToLive)
                   throws IPWorksException

The maximum number of subnets that a datagram can traverse.

The default value for this property is 0, which tells the bean to use the default TTL value of the underlying TCP/IP subsystem. Depending on the application, you can specify a value between 1 and 255.

IPWorksException

config

public java.lang.String config(java.lang.String configurationString)
                        throws IPWorksException

Sets or retrieves a beanconfiguration setting.

Config is a generic method available in every bean. It is used to set and retrieveconfiguration settingsfor the bean.

Configuration settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the bean, access to these internal properties is provided through the Config method.

To set a configuration setting named PROPERTY , you must call Config("PROPERTY=VALUE") , where VALUE is the value of the setting expressed as a string. For boolean values, use the strings "True", "False", "0", "1", "Yes", or "No" (case does not matter).

To read (query) the value of a configuration setting, you must call Config("PROPERTY") . The value will be returned as a string.

IPWorksException

doEvents

public void doEvents()
              throws IPWorksException

Processes events from the internal message queue.

When DoEvents is called, the bean processes any available events. If no events are available, it waits for a preset period of time, and then returns.

IPWorksException

send

public void send(byte[] text)
          throws IPWorksException

Send data to the remote host.

Calling this method is equivalent to setting the DataToSend property to Text .

Example (Send Data)

 UDPPortControl.LocalPort = 8765 
 UDPPortControl.RemotePort = 8765 
 UDPPortControl.RemoteHost = "HostNameOrIPAddress"
 UDPPortControl.Active = True
 UDPPortControl.Send("Hello!") 

IPWorksException

addUdpportEventListener

public void addUdpportEventListener(ipworks.UdpportEventListener l)
                             throws java.util.TooManyListenersException

java.util.TooManyListenersException

removeUdpportEventListener

public void removeUdpportEventListener(ipworks.UdpportEventListener l)