1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one 3 * or more contributor license agreements. See the NOTICE file 4 * distributed with this work for additional information 5 * regarding copyright ownership. The ASF licenses this file 6 * to you under the Apache License, Version 2.0 (the 7 * "License"); you may not use this file except in compliance 8 * with the License. You may obtain a copy of the License at 9 * 10 * http://www.apache.org/licenses/LICENSE-2.0 11 * 12 * Unless required by applicable law or agreed to in writing, 13 * software distributed under the License is distributed on an 14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 15 * KIND, either express or implied. See the License for the 16 * specific language governing permissions and limitations 17 * under the License. 18 * 19 */ 20 package org.apache.mina.example.tennis; 21 22 /** 23 * A tennis ball which has TTL value and state whose value is one of 'PING' and 24 * 'PONG'. 25 * 26 * @author The Apache MINA Project (dev@mina.apache.org) 27 */ 28 public class TennisBall { 29 private final boolean ping; 30 31 private final int ttl; 32 33 /** 34 * Creates a new ball with the specified TTL (Time To Live) value. 35 */ 36 public TennisBall(int ttl) { 37 this(ttl, true); 38 } 39 40 /** 41 * Creates a new ball with the specified TTL value and PING/PONG state. 42 */ 43 private TennisBall(int ttl, boolean ping) { 44 this.ttl = ttl; 45 this.ping = ping; 46 } 47 48 /** 49 * Returns the TTL value of this ball. 50 */ 51 public int getTTL() { 52 return ttl; 53 } 54 55 /** 56 * Returns the ball after {@link TennisPlayer}'s stroke. 57 * The returned ball has decreased TTL value and switched PING/PONG state. 58 */ 59 public TennisBall stroke() { 60 return new TennisBall(ttl - 1, !ping); 61 } 62 63 /** 64 * Returns string representation of this message (<code>[PING|PONG] 65 * (TTL)</code>). 66 */ 67 @Override 68 public String toString() { 69 if (ping) { 70 return "PING (" + ttl + ")"; 71 } else { 72 return "PONG (" + ttl + ")"; 73 } 74 } 75 }