Apache Mina入门MINA 基本类的描述
IoAccepter 相当于网络应用程序中的服务器端
IoConnector 相当于客户端
IoSession 当前客户端到服务器端的一个连接实例
IoHandler 业务处理逻辑
IoFilter 过滤器用于悬接通讯层接口与业务层接口
 
服务器端:MinaServer.java
public class MinaServer {
             private static final int SERVER_PORT = 9990;
    
             public static void main(String[] args) throws Throwable{
                            //服务端入口
                            IoAcceptor acceptor = new SocketAcceptor();
                            SocketAcceptorConfig cfg = new SocketAcceptorConfig();
                            cfg.setReuseAddress(true);
                            //设定这个过滤器将以对象为单位读取数据
                            cfg.getFilterChain().addLast("codec",
new ProtocolCodecFilter(new ObjectSerializationCodecFactory()));
                            //添加日志过滤器
                            cfg.getFilterChain().addLast("logger", new LoggingFilter());
                            //接收访问的连接和到IoHandler触发事件
             acceptor.bind(new InetSocketAddress(SERVER_PORT),new ServerHandler(), cfg);
                            System.out.println("The server Listening on port " + SERVER_PORT);
             }
}    
    
服务器端业务处理类:
public class ServerHandler extends IoHandlerAdapter
{
             /**
                * 有新连接时触发
                */

             public void sessionOpened(IoSession session) {
                            System.out.println("sessionOpened");
             }
             /**
                * 收到来自客户端的消息
                */

             public void messageReceived(IoSession session, Object message) {
                            System.out.println("server messageReceived!");
                            CityMessage cm = (CityMessage)message;
                            System.out.println(cm.getCode()+":"+cm.getName());
                            //将消息发向客户端
                            session.write(cm);
             }
             /**
                * 当有异常发生时触发
                */

             public void exceptionCaught(IoSession session, Throwable cause) {
                            session.close();
             }
             /**
                * 连接被关闭时触发
                */

             public void sessionClosed(IoSession ssn) throws Exception {
                            System.out.println("session closed from " + ssn.getRemoteAddress());
             }
}    
    
要发送的消息对象:
public class CityMessage implements Serializable{
             private int code;
             private String name;
             public int getCode() {
                            return code;
             }
             public void setCode(int code) {
                            this.code = code;
             }
             public String getName() {
                            return name;
             }
             public void setName(String name) {
                            this.name = name;
             }
}    
    
客户端:
public class MinaClient {
             private static final String HOSTNAME = "localhost";        
        private static final int PORT = 9990;        
    
        public static void main( String[] args ) throws Throwable{        
                //Connector为客户端入口
                     SocketConnector connector = new SocketConnector();                        
                SocketConnectorConfig cfg = new SocketConnectorConfig();        
                //设定这个过滤器将以对象为单位读取数据
                cfg.getFilterChain().addLast("codec",    
                                                                                                                        new ProtocolCodecFilter( new ObjectSerializationCodecFactory() ) );        
                //添加日志过滤器
                cfg.getFilterChain().addLast( "logger", new LoggingFilter() );        
                //向远程服务器发起连接,触发事件到IoHandler    
                connector.connect(new InetSocketAddress( HOSTNAME, PORT ),        
                                                new ClientHandler(), cfg );        
        }        
}    
    
客户端业务处理类:
public class ClientHandler extends IoHandlerAdapter {
             public ClientHandler() {
                            super();
             }
             /**
                * 有新连接时触发
                */

             public void sessionOpened(IoSession session) {
                            // 创建一个cityMessage发送
                            CityMessage cm = new CityMessage();
                            cm.setCode(547600);
                            cm.setName("凤山");
                            session.write(cm);
             }
             /**
                * 收到来自客户端的消息
                */

             public void messageReceived(IoSession session, Object message) {
                            System.out.println("client messageReceived!");
                            CityMessage cm = (CityMessage)message;
                            System.out.println(cm.getCode()+":"+cm.getName());
             }
             /**
                * 当有异常发生时触发
                */

             public void exceptionCaught(IoSession session, Throwable cause) {
                            session.close();
             }
             /**
                * 连接被关闭时触发
                */

             public void sessionClosed(IoSession ssn) throws Exception {
                            System.out.println("session closed from " + ssn.getRemoteAddress());
             }
}    
开发一个Mina应用,简单的说,就是创建连结,设定过滤规则,编写自己的消息处理器这三步!
 
过滤器:
ObjectSerializationCodecFactory:设定这个过滤器将以对象为单位读取数据。
TextLineCodecFactory:设定这个过滤器将一行一行(/r/n)的读取数据
 
注意:(摘抄自网上) apache mina建立的socket不管是采用TCP或是UDP,在Filter不添加codec选项的情况下,由IoHandlerAdapter派生的处理handler 类中public void messageReceived(IoSession session, Object message){}函数里的message对象是IoBuffer的实例,如下:
@Override
        public void messageReceived(IoSession session, Object message)
                        throws Exception {

                if (! (message instanceof IoBuffer)) {
                            return;
                     }

                IoBuffer rb = (IoBuffer) message;
                callback.messageReceived(java.nio.ByteBuffer.wrap(rb.array(), 0, rb.buf().limit()));
        }



如果你使用mina建立一个socket添加了如下:
IoFilter CODEC_FILTER = new ProtocolCodecFilter(
                new TextLineCodecFactory());
connector(acceptor).getFilterChain().addLast("codec", CODEC_FILTER);
如果发送数据的socket不是同样的设置或者不是利用mina建立的socket则发送数据的时候需要在数据末尾添加‘\n’,以表示字符串结束。