Java tutorial
/* * 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.chargen; import java.io.InputStream; import org.apache.commons.net.SocketClient; /*** * The CharGenTCPClient class is a TCP implementation of a client for the * character generator protocol described in RFC 864. It can also be * used for Systat (RFC 866), Quote of the Day (RFC 865), and netstat * (port 15). All of these protocols involve connecting to the appropriate * port, and reading data from an input stream. The chargen protocol * actually sends data until the receiving end closes the connection. All * of the others send only a fixed amount of data and then close the * connection. * <p> * To use the CharGenTCPClient class, just establish a * connection with * {@link org.apache.commons.net.SocketClient#connect connect } * and call {@link #getInputStream getInputStream() } to access * the data. Don't close the input stream when you're done with it. Rather, * call {@link org.apache.commons.net.SocketClient#disconnect disconnect } * to clean up properly. * <p> * <p> * @see CharGenUDPClient ***/ public final class CharGenTCPClient extends SocketClient { /*** The systat port value of 11 according to RFC 866. ***/ public static final int SYSTAT_PORT = 11; /*** The netstat port value of 19. ***/ public static final int NETSTAT_PORT = 15; /*** The quote of the day port value of 17 according to RFC 865. ***/ public static final int QUOTE_OF_DAY_PORT = 17; /*** The character generator port value of 19 according to RFC 864. ***/ public static final int CHARGEN_PORT = 19; /*** The default chargen port. It is set to 19 according to RFC 864. ***/ public static final int DEFAULT_PORT = 19; /*** * The default constructor for CharGenTCPClient. It merely sets the * default port to <code> DEFAULT_PORT </code>. ***/ public CharGenTCPClient() { setDefaultPort(DEFAULT_PORT); } /*** * Returns an InputStream from which the server generated data can be * read. You should NOT close the InputStream when you're finished * reading from it. Rather, you should call * {@link org.apache.commons.net.SocketClient#disconnect disconnect } * to clean up properly. * <p> * @return An InputStream from which the server generated data can be read. ***/ public InputStream getInputStream() { return _input_; } }