001/* 002 * Licensed to the Apache Software Foundation (ASF) under one 003 * or more contributor license agreements. See the NOTICE file 004 * distributed with this work for additional information 005 * regarding copyright ownership. The ASF licenses this file 006 * to you under the Apache License, Version 2.0 (the 007 * "License"); you may not use this file except in compliance 008 * with the License. You may obtain a copy of the License at 009 * 010 * http://www.apache.org/licenses/LICENSE-2.0 011 * 012 * Unless required by applicable law or agreed to in writing, 013 * software distributed under the License is distributed on an 014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 015 * KIND, either express or implied. See the License for the 016 * specific language governing permissions and limitations 017 * under the License. 018 * 019 */ 020package org.apache.mina.example.sumup; 021 022import org.apache.mina.core.service.IoHandler; 023import org.apache.mina.core.service.IoHandlerAdapter; 024import org.apache.mina.core.session.IdleStatus; 025import org.apache.mina.core.session.IoSession; 026import org.apache.mina.example.sumup.message.AddMessage; 027import org.apache.mina.example.sumup.message.ResultMessage; 028import org.slf4j.Logger; 029import org.slf4j.LoggerFactory; 030 031/** 032 * {@link IoHandler} for SumUp server. 033 * 034 * @author <a href="http://mina.apache.org">Apache MINA Project</a> 035 */ 036public class ServerSessionHandler extends IoHandlerAdapter { 037 038 private static final String SUM_KEY = "sum"; 039 040 private final static Logger LOGGER = LoggerFactory.getLogger(ServerSessionHandler.class); 041 042 @Override 043 public void sessionOpened(IoSession session) { 044 // set idle time to 60 seconds 045 session.getConfig().setIdleTime(IdleStatus.BOTH_IDLE, 60); 046 047 // initial sum is zero 048 session.setAttribute(SUM_KEY, Integer.valueOf(0)); 049 } 050 051 @Override 052 public void messageReceived(IoSession session, Object message) { 053 // client only sends AddMessage. otherwise, we will have to identify 054 // its type using instanceof operator. 055 AddMessage am = (AddMessage) message; 056 057 // add the value to the current sum. 058 int sum = ((Integer) session.getAttribute(SUM_KEY)).intValue(); 059 int value = am.getValue(); 060 long expectedSum = (long) sum + value; 061 if (expectedSum > Integer.MAX_VALUE || expectedSum < Integer.MIN_VALUE) { 062 // if the sum overflows or underflows, return error message 063 ResultMessage rm = new ResultMessage(); 064 rm.setSequence(am.getSequence()); // copy sequence 065 rm.setOk(false); 066 session.write(rm); 067 } else { 068 // sum up 069 sum = (int) expectedSum; 070 session.setAttribute(SUM_KEY, Integer.valueOf(sum)); 071 072 // return the result message 073 ResultMessage rm = new ResultMessage(); 074 rm.setSequence(am.getSequence()); // copy sequence 075 rm.setOk(true); 076 rm.setValue(sum); 077 session.write(rm); 078 } 079 } 080 081 @Override 082 public void sessionIdle(IoSession session, IdleStatus status) { 083 LOGGER.info("Disconnecting the idle."); 084 // disconnect an idle client 085 session.close(true); 086 } 087 088 @Override 089 public void exceptionCaught(IoSession session, Throwable cause) { 090 // close the connection on exceptional situation 091 session.close(true); 092 } 093}