Java tutorial
/* * Copyright 2001-2005 The Apache Software Foundation * * Licensed 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.eredlab.g4.ccl.net; import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; /*** * The DaytimeTCPClient class is a TCP implementation of a client for the * Daytime protocol described in RFC 867. To use the class, merely * establish a connection with * {@link org.apache.commons.net.SocketClient#connect connect } * and call {@link #getTime getTime() } to retrieve the daytime * string, then * call {@link org.apache.commons.net.SocketClient#disconnect disconnect } * to close the connection properly. * <p> * <p> * @author Daniel F. Savarese * @see DaytimeUDPClient ***/ public final class DaytimeTCPClient extends SocketClient { /*** The default daytime port. It is set to 13 according to RFC 867. ***/ public static final int DEFAULT_PORT = 13; // Received dates will likely be less than 64 characters. // This is a temporary buffer used while receiving data. private char[] __buffer = new char[64]; /*** * The default DaytimeTCPClient constructor. It merely sets the default * port to <code> DEFAULT_PORT </code>. ***/ public DaytimeTCPClient() { setDefaultPort(DEFAULT_PORT); } /*** * Retrieves the time string from the server and returns it. 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 <code> getTime() </code> again. * <p> * @return The time string retrieved from the server. * @exception IOException If an error occurs while fetching the time string. ***/ public String getTime() throws IOException { int read; StringBuffer result = new StringBuffer(__buffer.length); BufferedReader reader; reader = new BufferedReader(new InputStreamReader(_input_)); while (true) { read = reader.read(__buffer, 0, __buffer.length); if (read <= 0) break; result.append(__buffer, 0, read); } return result.toString(); } }