001 /* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017 018 package org.apache.commons.net.time; 019 020 import java.io.DataInputStream; 021 import java.io.IOException; 022 import java.util.Date; 023 024 import org.apache.commons.net.SocketClient; 025 026 /*** 027 * The TimeTCPClient class is a TCP implementation of a client for the 028 * Time protocol described in RFC 868. To use the class, merely 029 * establish a connection with 030 * {@link org.apache.commons.net.SocketClient#connect connect } 031 * and call either {@link #getTime getTime() } or 032 * {@link #getDate getDate() } to retrieve the time, then 033 * call {@link org.apache.commons.net.SocketClient#disconnect disconnect } 034 * to close the connection properly. 035 * <p> 036 * <p> 037 * @author Daniel F. Savarese 038 * @see TimeUDPClient 039 ***/ 040 041 public final class TimeTCPClient extends SocketClient 042 { 043 /*** The default time port. It is set to 37 according to RFC 868. ***/ 044 public static final int DEFAULT_PORT = 37; 045 046 /*** 047 * The number of seconds between 00:00 1 January 1900 and 048 * 00:00 1 January 1970. This value can be useful for converting 049 * time values to other formats. 050 ***/ 051 public static final long SECONDS_1900_TO_1970 = 2208988800L; 052 053 /*** 054 * The default TimeTCPClient constructor. It merely sets the default 055 * port to <code> DEFAULT_PORT </code>. 056 ***/ 057 public TimeTCPClient () 058 { 059 setDefaultPort(DEFAULT_PORT); 060 } 061 062 /*** 063 * Retrieves the time from the server and returns it. The time 064 * is the number of seconds since 00:00 (midnight) 1 January 1900 GMT, 065 * as specified by RFC 868. This method reads the raw 32-bit big-endian 066 * unsigned integer from the server, converts it to a Java long, and 067 * returns the value. 068 * <p> 069 * The server will have closed the connection at this point, so you should 070 * call 071 * {@link org.apache.commons.net.SocketClient#disconnect disconnect } 072 * after calling this method. To retrieve another time, you must 073 * initiate another connection with 074 * {@link org.apache.commons.net.SocketClient#connect connect } 075 * before calling <code> getTime() </code> again. 076 * <p> 077 * @return The time value retrieved from the server. 078 * @exception IOException If an error occurs while fetching the time. 079 ***/ 080 public long getTime() throws IOException 081 { 082 DataInputStream input; 083 input = new DataInputStream(_input_); 084 return (input.readInt() & 0xffffffffL); 085 } 086 087 /*** 088 * Retrieves the time from the server and returns a Java Date 089 * containing the time converted to the local timezone. 090 * <p> 091 * The server will have closed the connection at this point, so you should 092 * call 093 * {@link org.apache.commons.net.SocketClient#disconnect disconnect } 094 * after calling this method. To retrieve another time, you must 095 * initiate another connection with 096 * {@link org.apache.commons.net.SocketClient#connect connect } 097 * before calling <code> getDate() </code> again. 098 * <p> 099 * @return A Date value containing the time retrieved from the server 100 * converted to the local timezone. 101 * @exception IOException If an error occurs while fetching the time. 102 ***/ 103 public Date getDate() throws IOException 104 { 105 return new Date((getTime() - SECONDS_1900_TO_1970)*1000L); 106 } 107 108 } 109