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 * @see TimeUDPClient 38 ***/ 39 40 public final class TimeTCPClient extends SocketClient 41 { 42 /*** The default time port. It is set to 37 according to RFC 868. ***/ 43 public static final int DEFAULT_PORT = 37; 44 45 /*** 46 * The number of seconds between 00:00 1 January 1900 and 47 * 00:00 1 January 1970. This value can be useful for converting 48 * time values to other formats. 49 ***/ 50 public static final long SECONDS_1900_TO_1970 = 2208988800L; 51 52 /*** 53 * The default TimeTCPClient constructor. It merely sets the default 54 * port to <code> DEFAULT_PORT </code>. 55 ***/ 56 public TimeTCPClient () 57 { 58 setDefaultPort(DEFAULT_PORT); 59 } 60 61 /*** 62 * Retrieves the time from the server and returns it. The time 63 * is the number of seconds since 00:00 (midnight) 1 January 1900 GMT, 64 * as specified by RFC 868. This method reads the raw 32-bit big-endian 65 * unsigned integer from the server, converts it to a Java long, and 66 * returns the value. 67 * <p> 68 * The server will have closed the connection at this point, so you should 69 * call 70 * {@link org.apache.commons.net.SocketClient#disconnect disconnect } 71 * after calling this method. To retrieve another time, you must 72 * initiate another connection with 73 * {@link org.apache.commons.net.SocketClient#connect connect } 74 * before calling <code> getTime() </code> again. 75 * <p> 76 * @return The time value retrieved from the server. 77 * @exception IOException If an error occurs while fetching the time. 78 ***/ 79 public long getTime() throws IOException 80 { 81 DataInputStream input; 82 input = new DataInputStream(_input_); 83 return (input.readInt() & 0xffffffffL); 84 } 85 86 /*** 87 * Retrieves the time from the server and returns a Java Date 88 * containing the time converted to the local timezone. 89 * <p> 90 * The server will have closed the connection at this point, so you should 91 * call 92 * {@link org.apache.commons.net.SocketClient#disconnect disconnect } 93 * after calling this method. To retrieve another time, you must 94 * initiate another connection with 95 * {@link org.apache.commons.net.SocketClient#connect connect } 96 * before calling <code> getDate() </code> again. 97 * <p> 98 * @return A Date value containing the time retrieved from the server 99 * converted to the local timezone. 100 * @exception IOException If an error occurs while fetching the time. 101 ***/ 102 public Date getDate() throws IOException 103 { 104 return new Date((getTime() - SECONDS_1900_TO_1970)*1000L); 105 } 106 107 } 108