NTPUDPClient (Apache Commons Net 3.4 API)

java.lang.Object
- org.apache.commons.net.DatagramSocketClient
- - org.apache.commons.net.ntp.NTPUDPClient

```
public final class NTPUDPClient
extends DatagramSocketClient
```
The NTPUDPClient class is a UDP implementation of a client for the Network Time Protocol (NTP) described in RFC 1305 as well as the Simple Network Time Protocol (SNTP) in RFC-2030. To use the class, merely open a local datagram socket with open and call getTime to retrieve the time. Then call close to close the connection properly. Successive calls to getTime are permitted without re-establishing a connection. That is because UDP is a connectionless protocol and the Network Time Protocol is stateless.

Version:

$Revision: 1570303 $

Field Summary

Fields
Modifier and Type Field and Description

static int DEFAULT_PORT
The default NTP port.
- Fields inherited from class org.apache.commons.net.DatagramSocketClient
  _isOpen_, _socket_, _socketFactory_, _timeout_

Fields
Modifier and Type	Field and Description
`static int`	`DEFAULT_PORT` The default NTP port.

Constructor Summary

Constructors
Constructor and Description

NTPUDPClient()

Constructors
Constructor and Description
`NTPUDPClient()`

Method Summary

Methods
Modifier and Type	Method and Description
`TimeInfo`	`getTime(InetAddress host)` Retrieves the time information from the specified server on the default NTP port and returns it.
`TimeInfo`	`getTime(InetAddress host, int port)` Retrieves the time information from the specified server and port and returns it.
`int`	`getVersion()` Returns the NTP protocol version number that client sets on request packet that is sent to remote host (e.g.
`void`	`setVersion(int version)` Sets the NTP protocol version number that client sets on request packet communicate with remote host.

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 NTP port. It is set to 123 according to RFC 1305.
    
    See Also:
    Constant Field Values
- Constructor Detail
  - NTPUDPClient
```
public NTPUDPClient()
```
- Method Detail
  - getTime
```
public TimeInfo getTime(InetAddress host,
               int port)
                 throws IOException
```
    Retrieves the time information from the specified server and port and returns it. The time is the number of miliiseconds since 00:00 (midnight) 1 January 1900 UTC, as specified by RFC 1305. This method reads the raw NTP packet and constructs a TimeInfo object that allows access to all the fields of the NTP message header.
    
    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 TimeInfo getTime(InetAddress host)
                 throws IOException
```
    Retrieves the time information from the specified server on the default NTP port and returns it. The time is the number of miliiseconds since 00:00 (midnight) 1 January 1900 UTC, as specified by RFC 1305. This method reads the raw NTP packet and constructs a TimeInfo object that allows access to all the fields of the NTP message header.
    
    Parameters:
    host - The address of the server.
    
    Returns:
    The time value retrieved from the server.
    
    Throws:
    
    IOException - If an error occurs while retrieving the time.
  - getVersion
```
public int getVersion()
```
    Returns the NTP protocol version number that client sets on request packet that is sent to remote host (e.g. 3=NTP v3, 4=NTP v4, etc.)
    
    Returns:
    the NTP protocol version number that client sets on request packet.
    See Also:
    setVersion(int)
  - setVersion
```
public void setVersion(int version)
```
    Sets the NTP protocol version number that client sets on request packet communicate with remote host.
    
    Parameters:
    version - the NTP protocol version number

Class NTPUDPClient

Field Summary

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

Constructor Summary

Method Summary

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

Methods inherited from class java.lang.Object

Field Detail

DEFAULT_PORT

Constructor Detail

NTPUDPClient

Method Detail

getTime

getTime

getVersion

setVersion