1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one or more 3 * contributor license agreements. See the NOTICE file distributed with 4 * this work for additional information regarding copyright ownership. 5 * The ASF licenses this file to You under the Apache License, Version 2.0 6 * (the "License"); you may not use this file except in compliance with 7 * the License. You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 */ 17 18 package org.apache.commons.net.time; 19 20 import java.io.DataInputStream; 21 import java.io.IOException; 22 import java.util.Date; 23 24 import org.apache.commons.net.SocketClient; 25 26 /*** 27 * The TimeTCPClient class is a TCP implementation of a client for the 28 * Time protocol described in RFC 868. To use the class, merely 29 * establish a connection with 30 * {@link org.apache.commons.net.SocketClient#connect connect } 31 * and call either {@link #getTime getTime() } or 32 * {@link #getDate getDate() } to retrieve the time, then 33 * call {@link org.apache.commons.net.SocketClient#disconnect disconnect } 34 * to close the connection properly. 35 * <p> 36 * <p> 37 * @author Daniel F. Savarese 38 * @see TimeUDPClient 39 ***/ 40 41 public final class TimeTCPClient extends SocketClient 42 { 43 /*** The default time port. It is set to 37 according to RFC 868. ***/ 44 public static final int DEFAULT_PORT = 37; 45 46 /*** 47 * The number of seconds between 00:00 1 January 1900 and 48 * 00:00 1 January 1970. This value can be useful for converting 49 * time values to other formats. 50 ***/ 51 public static final long SECONDS_1900_TO_1970 = 2208988800L; 52 53 /*** 54 * The default TimeTCPClient constructor. It merely sets the default 55 * port to <code> DEFAULT_PORT </code>. 56 ***/ 57 public TimeTCPClient () 58 { 59 setDefaultPort(DEFAULT_PORT); 60 } 61 62 /*** 63 * Retrieves the time from the server and returns it. The time 64 * is the number of seconds since 00:00 (midnight) 1 January 1900 GMT, 65 * as specified by RFC 868. This method reads the raw 32-bit big-endian 66 * unsigned integer from the server, converts it to a Java long, and 67 * returns the value. 68 * <p> 69 * The server will have closed the connection at this point, so you should 70 * call 71 * {@link org.apache.commons.net.SocketClient#disconnect disconnect } 72 * after calling this method. To retrieve another time, you must 73 * initiate another connection with 74 * {@link org.apache.commons.net.SocketClient#connect connect } 75 * before calling <code> getTime() </code> again. 76 * <p> 77 * @return The time value retrieved from the server. 78 * @exception IOException If an error occurs while fetching the time. 79 ***/ 80 public long getTime() throws IOException 81 { 82 DataInputStream input; 83 input = new DataInputStream(_input_); 84 return (input.readInt() & 0xffffffffL); 85 } 86 87 /*** 88 * Retrieves the time from the server and returns a Java Date 89 * containing the time converted to the local timezone. 90 * <p> 91 * The server will have closed the connection at this point, so you should 92 * call 93 * {@link org.apache.commons.net.SocketClient#disconnect disconnect } 94 * after calling this method. To retrieve another time, you must 95 * initiate another connection with 96 * {@link org.apache.commons.net.SocketClient#connect connect } 97 * before calling <code> getDate() </code> again. 98 * <p> 99 * @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