com.groupbyinc.common.apache.commons.net.time.TimeTCPClient Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.commons.net.time;
import java.io.DataInputStream;
import java.io.IOException;
import java.util.Date;
import org.apache.commons.net.SocketClient;
/***
* The TimeTCPClient class is a TCP implementation of a client for the
* Time protocol described in RFC 868. To use the class, merely
* establish a connection with
* {@link org.apache.commons.net.SocketClient#connect connect }
* and call either {@link #getTime getTime() } or
* {@link #getDate getDate() } to retrieve the time, then
* call {@link org.apache.commons.net.SocketClient#disconnect disconnect }
* to close the connection properly.
*
*
* @see TimeUDPClient
***/
public final class TimeTCPClient extends SocketClient
{
/*** The default time port. It is set to 37 according to RFC 868. ***/
public static final int DEFAULT_PORT = 37;
/***
* 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.
***/
public static final long SECONDS_1900_TO_1970 = 2208988800L;
/***
* The default TimeTCPClient constructor. It merely sets the default
* port to DEFAULT_PORT .
***/
public TimeTCPClient ()
{
setDefaultPort(DEFAULT_PORT);
}
/***
* Retrieves the time from the server 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.
*
* The server will have closed the connection at this point, so you should
* call
* {@link org.apache.commons.net.SocketClient#disconnect disconnect }
* after calling this method. To retrieve another time, you must
* initiate another connection with
* {@link org.apache.commons.net.SocketClient#connect connect }
* before calling getTime() again.
*
* @return The time value retrieved from the server.
* @exception IOException If an error occurs while fetching the time.
***/
public long getTime() throws IOException
{
DataInputStream input;
input = new DataInputStream(_input_);
return (input.readInt() & 0xffffffffL);
}
/***
* Retrieves the time from the server and returns a Java Date
* containing the time converted to the local timezone.
*
* The server will have closed the connection at this point, so you should
* call
* {@link org.apache.commons.net.SocketClient#disconnect disconnect }
* after calling this method. To retrieve another time, you must
* initiate another connection with
* {@link org.apache.commons.net.SocketClient#connect connect }
* before calling getDate() again.
*
* @return A Date value containing the time retrieved from the server
* converted to the local timezone.
* @exception IOException If an error occurs while fetching the time.
***/
public Date getDate() throws IOException
{
return new Date((getTime() - SECONDS_1900_TO_1970)*1000L);
}
}