mina入门学习

时间：2010-07-18 来源：liaoshaoyao

1、 MINA简介
    Apache MINA(Multipurpose Infrastructure for Network Applications)发行的 MINA 版本支持基于 Java NIO 技术的 TCP/UDP 应用程序开发、串口通讯程序。 MINA是一个网络应用框架，在不牺牲性能和可扩展性的前提下用于解决如下问题：
   1)快速开发自己的应用
   2）高可维护性、高可复用性：网络I/O编码，消息的编码/解码、业务逻辑互相分离
   3）相对容易的进行单元测试

2、原理图（对象传送）：
   [img][/img]

3、 MINA主要类介绍
    1）IoFilters: IoFilter为MINA的功能扩展提供了接口。它拦截所有的IO事件进行事件的预处理和后处理(AOP)。我们可以把它想象成Servlet的filters。IoFilter能够实现以下几种目的：事件日志、性能检测、数据转换(e.g. SSL support)，codec防火墙…等等。
   2）codec: ProtocolCodecFactory
MINA提供了方便的Protocol支持。如上说讲，codec在IoFilters中设置。通过它的Encoder和Decoder，可以方便的扩展并支持各种基于Socket的网络协议，比如HTTP服务器、FTP服务器、Telnet服务器等等。
   要实现自己的编码/解码器(codec)只需要实现interface: ProtocolCodecFactory即可.在MINA 1.0版本，MINA已经实现了几个常用的(codec factory):
DemuxingProtocolCodecFactory,
NettyCodecFactory,
ObjectSerializationCodecFactory,
TextLineCodecFactory
    3）business logic: IoHandler
MINA中，所有的业务逻辑都有实现了IoHandler的class完成
interfaceHandles:
all protocol events fired by MINA. There are 6 event handler methods, and they are all invoked by MINA automatically.
当事件发生时，将触发IoHandler中的方法:
sessionCreated(),
sessionOpened(),
sessionClosed(),
sessionIdle(),
exceptionCaught(),
messageReceived(),
messageSent()

    4） MINA的高级主题：线程模式
MINA通过它灵活的filter机制来提供多种线程模型。
没有线程池过滤器被使用时MINA运行在一个单线程模式。
如果添加了一个IoThreadPoolFilter到IoAcceptor，将得到一个leader-follower模式的线程池。
如果再添加一个ProtocolThreadPoolFilter，server将有两个线程池；
一个(IoThreadPoolFilter)被用于对message对象进行转换，另外一个(ProtocolThreadPoolFilter)被用于处理业务逻辑。
SimpleServiceRegistry加上IoThreadPoolFilter和ProtocolThreadPoolFilter的缺省实现即可适用于需
要高伸缩性的应用。如果想使用自己的线程模型，请参考SimpleServiceRegistry的源代码，并且自己初始化Acceptor。
MINA 1.O中，IoHandler的实现类：
ChainedIoHandler,
DemuxingIoHandler,
IoHandlerAdapter,
SingleSessionIoHandlerDelegate,
StreamIoHandler

具体细节可参考javadoc。

4、 MINA开发示例
    首先到apache下载相关文件，最新版是2.0，最新稳定版是1.7。导入全部jar包至工程

    开发的一般步骤：
    1）、客户端建立连接： IoAcceptor acceptor = new SocketAcceptor();//建立client连接或者
                          SocketConnector connector = new SocketConnector();
   2）、 Server段的属性配置
    3）、绑定address和business Logic

5、 Demo源代码
    Client.java

import java.net.InetSocketAddress;

import org.apache.mina.common.IoSession;
import org.apache.mina.filter.LoggingFilter;
import org.apache.mina.filter.codec.ProtocolCodecFilter;
import org.apache.mina.filter.codec.serialization.ObjectSerializationCodecFactory;
import org.apache.mina.transport.socket.nio.SocketConnector;
import org.apache.mina.transport.socket.nio.SocketConnectorConfig;

public class Client
{
    private static final String HOSTNAME = "localhost";
    private static final int PORT = 8080;
    private static final int CONNECT_TIMEOUT = 30; // seconds


    public static void main( String[] args ) throws Throwable
    {
        SocketConnector connector = new SocketConnector();
        // Configure the service.
        SocketConnectorConfig cfg = new SocketConnectorConfig();
        cfg.setConnectTimeout( CONNECT_TIMEOUT );
          cfg.getFilterChain().addLast(
                    "codec",
                    new ProtocolCodecFilter( new ObjectSerializationCodecFactory() ) );

        cfg.getFilterChain().addLast( "logger", new LoggingFilter() );

        IoSession session;
        Message msg = new Message(0,1,"hello");
        connector.connect(new InetSocketAddress( HOSTNAME, PORT ),
                        new ClientSessionHandler(msg), cfg );

    }
}


    ClientSessionHandler.java

import org.apache.mina.common.IoHandlerAdapter;
import org.apache.mina.common.IoSession;
import org.apache.mina.util.SessionLog;

public class ClientSessionHandler extends IoHandlerAdapter
{
    private Object msg;

    public ClientSessionHandler(Object msg)
    {
        this.msg = msg;
    }


    public void sessionOpened( IoSession session )
    {
        session.write(this.msg);
    }

    public void messageReceived( IoSession session, Object message )
    {
        System.out.println("in messageReceived(Client)");
        Message rm = (Message ) message;
        SessionLog.debug(session, rm.getMsgBody());
        System.out.println("message is: " + rm.getMsgBody());
        session.write(rm);
    }

    public void exceptionCaught( IoSession session, Throwable cause )
    {
        session.close();
    }
}


     传输的对象Message.java

import java.io.Serializable;

public class Message implements Serializable {

    private int type;
    private int status;
    private String msgBody;

    public Message(int type, int status, String msgBody)
    {
        this.type = type;
        this.status = status;
        this.msgBody = msgBody;
    }

    public String getMsgBody() {
        return msgBody;
    }

    public void setMsgBody(String msgBody) {
        this.msgBody = msgBody;
    }

    public int getStatus() {
        return status;
    }

    public void setStatus(int status) {
        this.status = status;
    }

    public int getType() {
        return type;
    }

    public void setType(int type) {
        this.type = type;
    }
}

     Server.java


import java.net.InetSocketAddress;

import org.apache.mina.common.IoAcceptor;
import org.apache.mina.filter.LoggingFilter;
import org.apache.mina.filter.codec.ProtocolCodecFilter;
import org.apache.mina.filter.codec.serialization.ObjectSerializationCodecFactory;
import org.apache.mina.transport.socket.nio.SocketAcceptor;
import org.apache.mina.transport.socket.nio.SocketAcceptorConfig;

public class Server
{
    private static final int SERVER_PORT = 8080;

    public static void main( String[] args ) throws Throwable
    {
        IoAcceptor acceptor = new SocketAcceptor();

        // Prepare the service configuration.
        SocketAcceptorConfig cfg = new SocketAcceptorConfig();
        cfg.setReuseAddress( true );

        cfg.getFilterChain().addLast(
                    "codec",
                    new ProtocolCodecFilter( new ObjectSerializationCodecFactory() ) );
        cfg.getFilterChain().addLast( "logger", new LoggingFilter() );

        acceptor.bind(
                new InetSocketAddress( SERVER_PORT ),
                new ServerSessionHandler( ), cfg );

        System.out.println( "The server Listening on port " + SERVER_PORT );
    }
}

    ServerSessionHandler.java


import org.apache.mina.common.IdleStatus;
import org.apache.mina.common.IoHandlerAdapter;
import org.apache.mina.common.IoSession;
import org.apache.mina.util.SessionLog;

public class ServerSessionHandler extends IoHandlerAdapter
{
    public void sessionOpened( IoSession session )
    {
        // set idle time to 60 seconds
        session.setIdleTime( IdleStatus.BOTH_IDLE, 60 );
        session.setAttribute("times",new Integer(0));
    }

    public void messageReceived( IoSession session, Object message )
    {
        System.out.println("in messageReceived(Server)");
        int times = ((Integer)(session.getAttribute("times"))).intValue();
        System.out.println("tiems = " + times);
        // communicate 30 times,then close the session.
        if (times < 30)
        {
            times++;
            session.setAttribute("times", new Integer(times));
         Message msg;
         msg = (Message) message;
         msg.setMsgBody("in server side: " + msg.getMsgBody());
         System.out.println("begin send msg: " + msg.getMsgBody());
         session.write(msg);
        }
        else
        {
            session.close();
        }
    }

    public void sessionIdle( IoSession session, IdleStatus status )
    {
        SessionLog.info( session, "Disconnecting the idle." );
        // disconnect an idle client
        session.close();
    }

    public void exceptionCaught( IoSession session, Throwable cause )
    {
        // close the connection on exceptional situation
        session.close();
    }
}

5、 Demo异常处理
     不出意外的话，你运行程序会抛出如下异常：
       Exception in thread "main" java.lang.NoClassDefFoundError: org/slf4j/LoggerFactory
at org.apache.mina.util.NamePreservingRunnable.<init>(NamePreservingRunnable.java:32)
at org.apache.mina.transport.socket.nio.SocketAcceptor.startupWorker(SocketAcceptor.java:165)
at org.apache.mina.transport.socket.nio.SocketAcceptor.bind(SocketAcceptor.java:141)
at com.apusic.mina.Server.main(Server.java:29)
Caused by: java.lang.ClassNotFoundException: org.slf4j.LoggerFactory
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
... 4 more

   导入slf4j-api-1.5.2.jar解决

抛出新异常：
   SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder".
SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details.
Exception in thread "main" java.lang.NoClassDefFoundError: org/slf4j/impl/StaticLoggerBinder
at org.slf4j.LoggerFactory.<clinit>(LoggerFactory.java:60)
at org.apache.mina.util.NamePreservingRunnable.<init>(NamePreservingRunnable.java:32)
at org.apache.mina.transport.socket.nio.SocketAcceptor.startupWorker
(SocketAcceptor.java:165)
at org.apache.mina.transport.socket.nio.SocketAcceptor.bind(SocketAcceptor.java:141)
at com.apusic.mina.Server.main(Server.java:29)
Caused by: java.lang.ClassNotFoundException: org.slf4j.impl.StaticLoggerBinder
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
... 5 more
   导入slf4j-nop-1.5.2.jar解决
    所需的两个jar见附件

6、使用socket重写（不使用框架版，待下回分解）