org.apache.commons.net

Class 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 {@link org.apache.commons.net.DatagramSocketClient#open open } and call {@link #getTime getTime } or {@link #getTime getDate } to retrieve the time. Then call {@link org.apache.commons.net.DatagramSocketClient#close close } to close the connection properly. Unlike {@link org.apache.commons.net.TimeTCPClient}, successive calls to {@link #getTime getTime } or {@link #getDate getDate } are permitted without re-establishing a connection. That is because UDP is a connectionless protocol and the Time protocol is stateless.

Author: Daniel F. Savarese

See Also:

Field Summary
static intDEFAULT_PORT
The default time port.
static longSECONDS_1900_TO_1970
The number of seconds between 00:00 1 January 1900 and 00:00 1 January 1970.
Method Summary
DategetDate(InetAddress host, int port)
Retrieves the time from the server and returns a Java Date containing the time converted to the local timezone.
DategetDate(InetAddress host)
Same as getTime(host, DEFAULT_PORT); **
longgetTime(InetAddress host, int port)
Retrieves the time from the specified server and port and returns it.
longgetTime(InetAddress host)
Same as getTime(host, DEFAULT_PORT); **

Field Detail

DEFAULT_PORT

public static final int DEFAULT_PORT
The default time port. It is set to 37 according to RFC 868. **

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.

Method Detail

getDate

public Date getDate(InetAddress host, int port)
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: IOException If an error occurs while fetching the time.

getDate

public Date getDate(InetAddress host)
Same as getTime(host, DEFAULT_PORT); **

getTime

public long getTime(InetAddress host, int port)
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: IOException If an error occurs while retrieving the time.

getTime

public long getTime(InetAddress host)
Same as getTime(host, DEFAULT_PORT); **