概述

Mina是一个简洁易用的基于TCP/IP通信的Java框架。

Mina框架可以帮助我们快速开发高性能、高扩展性的网络通信应用，Mina提供了事件驱动、异步操作的编程模型，默认使用NIO作为底层支持。

官网地址：http://mina.apache.org/downloads-mina.html

下载地址：https://www.apache.org/dyn/closer.lua/mina/mina/2.0.22/apache-mina-2.0.22-bin.zip

Mina2.0.22：apache-mina-2.0.22.zip

3、一个简单的网络程序需要的最少jar包：mina-core-2.0.22.jar、slf4j-api-1.7.26.jar

4、开发一个Mina应用，简单的说，就是创建连接，设定过滤规则，编写自己的消息处理器。

服务端与客户端通信

服务端代码

import org.apache.mina.core.filterchain.DefaultIoFilterChainBuilder;
import org.apache.mina.filter.codec.ProtocolCodecFilter;
import org.apache.mina.filter.codec.textline.TextLineCodecFactory;
import org.apache.mina.transport.socket.SocketAcceptor;
import org.apache.mina.transport.socket.nio.NioSocketAcceptor;

import java.io.IOException;
import java.net.InetSocketAddress;

public class Server {
    public static void main(String[] args) {

        //创建一个非阳塞的server端socket，用NIO
        SocketAcceptor acceptor = new NioSocketAcceptor();
        //创建接收数据的过滤器
         DefaultIoFilterChainBuilder chain = acceptor.getFilterChain();
        //设定这个过滤器将一行一行(/r/n)读取数据
        chain.addLast("myChin", new ProtocolCodecFilter(new TextLineCodecFactory()));
        //设定服务器端的消息处理器：MinaServerHandler
        acceptor.setHandler(new MinaServerHandler());
        int bindPort = 9999; //服务器端口号
        //绑定端口，启动服务器
        try {
            acceptor.bind(new InetSocketAddress(bindPort));
        } catch (IOException e){
            e.printStackTrace();
        }
        System.out.println("Mina Server is Listing on: " + bindPort);
    }
}

import org.apache.mina.core.service.IoHandlerAdapter;
import org.apache.mina.core.session.IoSession;

//服务器端的消息处理器
public class MinaServerHandler extends IoHandlerAdapter {

    //一次会话被打开
    @Override
    public void sessionOpened(IoSession session) throws Exception {
        super.sessionOpened(session);
        System.out.println("welcome client " + session.getRemoteAddress());
    }

    //会话关闭
    @Override
    public void sessionClosed(IoSession session) throws Exception {
        super.sessionClosed(session);
        System.out.println("client close");
    }

    //接收消息
    @Override
    public void messageReceived(IoSession session, Object message) throws Exception {
        super.messageReceived(session, message);
        String msg = (String) message; //接收到的消息对象
        System.out.println("收到客户端发来的消息 " + msg);
        //向客户端发送消息对象
        session.write("echo:" + msg);
    }
}

测试

1、使用telnet测试

控制面板 → 程序 启用或关闭Windows功能 → 选择“Telnet 客户端”

win + R → 输入 cmd → telnet localhost 9999 → 输入内容

2、编写客户端代码

import org.apache.mina.core.filterchain.DefaultIoFilterChainBuilder;
import org.apache.mina.core.future.ConnectFuture;
import org.apache.mina.filter.codec.ProtocolCodecFilter;
import org.apache.mina.filter.codec.textline.TextLineCodecFactory;
import org.apache.mina.transport.socket.nio.NioSocketConnector;

import java.net.InetSocketAddress;
import java.util.Scanner;

public class Client {
    public static void main(String[] args) {
        NioSocketConnector connector = new NioSocketConnector();
        //创建接收数据的过滤器
         DefaultIoFilterChainBuilder chain = connector.getFilterChain();
        //设定这个过滤器将一行一行(/r/n)读取数据
        chain.addLast("myChin" , new ProtocolCodecFilter(new TextLineCodecFactory()));
        //设定客户端的消息处理器:MinaClientHandler
        connector.setHandler(new MinaClientHandler());
        //设置客户端连接超时时间为10s
        connector.setConnectTimeoutMillis(10000);
        // 连结到服务器:
        ConnectFuture cf = connector.connect(new InetSocketAddress("localhost", 9999));
        cf.awaitUninterruptibly(); //等待连接成功

        Scanner input = new Scanner(System.in);
        while (true) {
            System.out.println("请输入：");
            String info = input.nextLine();
            //发送消息
            cf.getSession().write(info);
        }

        //等待服务器连接关闭，结束长连接
        //cf.getSession().getCloseFuture().awaitUninterruptibly();
        //connector.dispose(); //关闭连接
    }
}

import org.apache.mina.core.service.IoHandlerAdapter;
import org.apache.mina.core.session.IoSession;

public class MinaClientHandler extends IoHandlerAdapter {
    @Override
    public void sessionOpened(IoSession session) throws Exception {
        super.sessionOpened(session);
        System.out.println("sessionOpened");
    }

    @Override
    public void sessionClosed(IoSession session) throws Exception {
        super.sessionClosed(session);
        System.out.println("sessionClosed");
    }

    @Override
    public void messageReceived(IoSession session, Object message) throws Exception {
        super.messageReceived(session, message);
        System.out.println(((String) message));
    }
}

使用Mina直接传送对象

1、public class Userinfo implements java.io.Serializable
2、服务器，客户端都设定以对象为单位
//设定这个过滤器将以对象为单位读取数据
ProtocolCodecFilter filter= new ProtocolCodecFilter(new ObjectSerializationCodecFactory());
chain.addLast("objectFilter",filter);
3、接收对象
public void messageReceived(IoSession session, Object message) throws Exception{
	//我们己设定了服务器解析消息的规则一个Userinfo对象为单位传输
    Userinfo us=(Userinfo)message;
}