net.time4j.clock.DaytimeClock Maven / Gradle / Ivy
/*
* -----------------------------------------------------------------------
* Copyright © 2013-2015 Meno Hochschild, Represents a connection to a DAYTIME-server following the old norm
* RFC 867.
*
* Note that the format of the server reply is not specified by the
* protocol. Furthermore, many internet time servers have stopped to
* support this old protocol. Actually in year 2014, at least the
* addresses "time.nist.gov" and "time.ien.it"
* are still working. Applications cannot expect more than second
* precision at best.
*
* @author Meno Hochschild
* @since 2.1
* @doctags.concurrency {threadsafe}
*/
/*[deutsch]
* Repräsentiert eine Verbindung zu einem DAYTIME-Server nach der
* alten Norm RFC 867.
*
* Hinweis: Das Format der Server-Antwort ist ein unspezifizierter String.
* Viele Uhrzeit-Server bieten inzwischen keine Unterstützung mehr.
* Aktuell im Jahr 2014 funktionieren wenigstens noch die Adressen
* "time.nist.gov" und "time.ien.it". Mehr als
* Sekundengenauigkeit ist nicht zu erwarten.
*
* @author Meno Hochschild
* @since 2.1
* @doctags.concurrency {threadsafe}
*/
public class DaytimeClock
extends NetTimeConnector {
//~ Statische Felder/Initialisierungen --------------------------------
private static final ChronoParser MJD_PARSER =
ChronoFormatter.setUp(PlainDate.class, Locale.ROOT).addPattern("ggggg", PatternType.CLDR).build();
private static final ChronoParser TIME_PARSER =
ChronoFormatter.setUp(PlainTime.class, Locale.ROOT).addPattern("HH:mm:ss", PatternType.CLDR).build();
private static final ChronoParser NIST_PARSER =
(text, status, attrs) -> {
int pos = 0;
while (!Character.isDigit(text.charAt(pos))) {
pos++;
}
PlainDate date =
MJD_PARSER.parse(
text.subSequence(pos, 5 + pos), status, attrs);
if (date != null) {
status.setPosition(0);
PlainTime time =
TIME_PARSER.parse(
text.subSequence(15 + pos, 23 + pos),
status,
attrs);
if (time != null) {
// leapsecond will be set to 59 in smart mode
return date.at(time).atUTC();
}
}
return null;
};
/**
* Defines an instance which supports the NIST-servers using
* the multiple-location-address "time.nist.gov" and
* a specific format.
*
* The format is documented at
* www.nist.gov.
*/
/*[deutsch]
* Definiert eine Instanz, die die NIST-Server mit der allgemeinen
* Adresse "time.nist.gov" und deren spezifisches
* Format verwendet.
*
* Das Format ist auf der Webseite
* www.nist.gov dokumentiert.
*/
public static final DaytimeClock NIST =
new DaytimeClock("time.nist.gov", NIST_PARSER);
//~ Instanzvariablen --------------------------------------------------
private final ChronoParser parser;
//~ Konstruktoren -----------------------------------------------------
/**
* Creates a new instance which uses the given time server on the
* port 13.
*
* @param server time server address (example: "time.nist.gov")
* @param parser object interpreting the server reply
*/
/*[deutsch]
* Erzeugt eine neue Instanz, die den angegebenen Uhrzeit-Server
* auf Port 13 benutzt.
*
* @param server time server address (example: "time.nist.gov")
* @param parser object interpreting the server reply
*/
public DaytimeClock(
String server,
ChronoParser parser
) {
super(new SimpleDaytimeConfiguration(server));
if (parser == null) {
throw new NullPointerException(
"Missing parser for translating any server reply.");
}
this.parser = parser;
}
//~ Methoden ----------------------------------------------------------
/**
* Tries to get the raw server timestamp as original string.
*
* @return unparsed server reply
* @throws IOException if connection fails
* @since 2.1
*/
/*[deutsch]
* Versucht, den Original-Server-Zeitstempel zu lesen.
*
* @return unparsed server reply
* @throws IOException if connection fails
* @since 2.1
*/
public String getRawTimestamp() throws IOException {
final NetTimeConfiguration config = this.getNetTimeConfiguration();
String address = config.getTimeServerAddress();
int port = config.getTimeServerPort();
int timeout = config.getConnectionTimeout();
return getDaytimeReply(address, port, timeout);
}
@Override
protected Moment doConnect()
throws ParseException, IOException {
final NetTimeConfiguration config = this.getNetTimeConfiguration();
String address = config.getTimeServerAddress();
int port = config.getTimeServerPort();
int timeout = config.getConnectionTimeout();
String time = getDaytimeReply(address, port, timeout);
this.log("DAYTIME-Server connected: ", time);
return this.parser.parse(time, new ParseLog(), Attributes.empty());
}
@Override
protected Class getConfigurationType() {
return NetTimeConfiguration.class;
}
// Original-Antwort eines älteren Uhrzeit-Servers holen (RFC 867)
private static String getDaytimeReply(
String address,
int port,
int timeout
) throws IOException {
IOException ioe = null;
Socket socket = null;
StringBuilder sb = null;
try {
socket = new Socket(address, port);
socket.setSoTimeout(timeout * 1000);
InputStream is = socket.getInputStream();
InputStreamReader ir = new InputStreamReader(is);
BufferedReader br = new BufferedReader(ir);
int len;
char[] chars = new char[100];
sb = new StringBuilder();
while ((len = br.read(chars)) != -1) {
sb.append(chars, 0, len);
}
is.close();
ir.close();
br.close();
} catch (IOException ex) {
ioe = ex;
} finally {
try {
if (socket != null) {
socket.close();
}
} catch (IOException ex) {
System.err.println(
"Ignored exception while closing time server socket: "
+ ex.getMessage()
);
ex.printStackTrace(System.err);
}
}
if (ioe == null) {
return sb.toString();
} else {
throw ioe;
}
}
//~ Innere Klassen ----------------------------------------------------
private static class SimpleDaytimeConfiguration
implements NetTimeConfiguration {
//~ Instanzvariablen ----------------------------------------------
private final String server;
//~ Konstruktoren -------------------------------------------------
SimpleDaytimeConfiguration(String server) {
super();
if (server == null) {
throw new NullPointerException("Missing time server address.");
}
this.server = server;
}
//~ Methoden ------------------------------------------------------
@Override
public String getTimeServerAddress() {
return this.server;
}
@Override
public int getTimeServerPort() {
return 13;
}
@Override
public int getConnectionTimeout() {
return DEFAULT_CONNECTION_TIMEOUT;
}
@Override
public int getClockShiftWindow() {
return 0;
}
@Override
public String toString() {
StringBuilder sb = new StringBuilder();
sb.append("SimpleDaytimeConfiguration:[server=");
sb.append(this.server);
sb.append(",port=");
sb.append(this.getTimeServerPort());
sb.append(']');
return sb.toString();
}
}
}
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