Package org.apache.commons.net.time

Class TimeUDPClient

java.lang.Object

org.apache.commons.net.DatagramSocketClient

org.apache.commons.net.time.TimeUDPClient

public final class TimeUDPClient
extends DatagramSocketClient

The TimeUDPClient class is a UDP implementation of a client for the Time protocol described in RFC 868. To use the class, merely open a local datagram socket with open and call getTime or getDate to retrieve the time. Then call close to close the connection properly. Unlike TimeTCPClient, successive calls to getTime or getDate are permitted without re-establishing a connection. That is because UDP is a connectionless protocol and the Time protocol is stateless.

See Also:

TimeTCPClient

Field Summary

Fields

Modifier and Type	Field	Description
static int	DEFAULT_PORT	The default time port.
static long	SECONDS_1900_TO_1970	The number of seconds between 00:00 1 January 1900 and 00:00 1 January 1970.

Fields inherited from class org.apache.commons.net.DatagramSocketClient

_isOpen_, _socket_, _socketFactory_, _timeout_

Constructor Summary

Constructors

Constructor	Description
TimeUDPClient()

Method Summary

Modifier and Type	Method	Description
java.util.Date	getDate(java.net.InetAddress host)	Same as getTime(host, DEFAULT_PORT);
java.util.Date	getDate(java.net.InetAddress host, int port)	Retrieves the time from the server and returns a Java Date containing the time converted to the local timezone.
long	getTime(java.net.InetAddress host)	Same as getTime(host, DEFAULT_PORT);
long	getTime(java.net.InetAddress host, int port)	Retrieves the time from the specified server and port and returns it.

Methods inherited from class org.apache.commons.net.DatagramSocketClient

close, getCharset, getCharsetName, getDefaultTimeout, getLocalAddress, getLocalPort, getSoTimeout, isOpen, open, open, open, setCharset, setDatagramSocketFactory, setDefaultTimeout, setSoTimeout

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_PORT

public static final int DEFAULT_PORT

The default time port. It is set to 37 according to RFC 868.

See Also:

Constant Field Values

SECONDS_1900_TO_1970

public static final long SECONDS_1900_TO_1970

The number of seconds between 00:00 1 January 1900 and 00:00 1 January 1970. This value can be useful for converting time values to other formats.

See Also:

Constant Field Values

Constructor Detail

TimeUDPClient

public TimeUDPClient()

Method Detail

getTime

public long getTime(java.net.InetAddress host,
                    int port)
             throws java.io.IOException

Retrieves the time from the specified server and port and returns it. The time is the number of seconds since 00:00 (midnight) 1 January 1900 GMT, as specified by RFC 868. This method reads the raw 32-bit big-endian unsigned integer from the server, converts it to a Java long, and returns the value.

Parameters:

host - The address of the server.

port - The port of the service.

Returns:

The time value retrieved from the server.

Throws:

java.io.IOException - If an error occurs while retrieving the time.

getTime

public long getTime(java.net.InetAddress host)
             throws java.io.IOException

Same as getTime(host, DEFAULT_PORT);

Parameters:

host - the time server

Returns:

the time returned from the server

Throws:

java.io.IOException - on error

getDate

public java.util.Date getDate(java.net.InetAddress host,
                              int port)
                       throws java.io.IOException

Retrieves the time from the server and returns a Java Date containing the time converted to the local timezone.

Parameters:

host - The address of the server.

port - The port of the service.

Returns:

A Date value containing the time retrieved from the server converted to the local timezone.

Throws:

java.io.IOException - If an error occurs while fetching the time.

getDate

public java.util.Date getDate(java.net.InetAddress host)
                       throws java.io.IOException

Same as getTime(host, DEFAULT_PORT);

Parameters:

host - the time server

Returns:

the date

Throws:

java.io.IOException - on error