Package org.apache.commons.net.time

Class TimeUDPClient

java.lang.Object
org.apache.commons.net.DatagramSocketClient
org.apache.commons.net.time.TimeUDPClient
All Implemented Interfaces:
AutoCloseable
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:

  • Field Details

    • DEFAULT_PORT

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

    • 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:

  • Constructor Details

  • Method Details

    • getDate

      public Date getDate(InetAddress host) throws IOException
      Same as getTime(host, DEFAULT_PORT);
      Parameters:
      host - the time-server
      Returns:
      the date
      Throws:
      IOException - on error

    • getDate

      public Date getDate(InetAddress host, int port) throws IOException
      Retrieves the time from the server and returns a Java Date containing the time converted to the local time zone.
      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 time zone.
      Throws:
      IOException - If an error occurs while fetching the time.

    • getTime

      public long getTime(InetAddress host) throws IOException
      Same as getTime(host, DEFAULT_PORT);
      Parameters:
      host - the time-server
      Returns:
      the time returned from the server
      Throws:
      IOException - on error

    • getTime

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