import java.io.IOException;

import java.net.InetSocketAddress;

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

import org.apache.mina.core.session.IdleStatus;

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

import org.apache.mina.filter.codec.ProtocolCodecFilter;

import org.apache.mina.filter.codec.textline.TextLineCodecFactory;

import org.apache.mina.transport.socket.nio.NioSocketAcceptor;

/**

 * 使用mina作为服务器进行socket通讯

 *

 * 需要jar包: mina-core-2.0.16.jar, slf4j-api-1.7.21.jar

 * jar包下载地址 : http://mina.apache.org/downloads-mina.html

 *

 */

public class MinaServer {

    public static void main(String[] args) {

        try {

            // 4步操作

            // 1.新建 NioSocketAcceptor 事例对象

            NioSocketAcceptor acceptor = new NioSocketAcceptor();

            // 2.设置消息处理对象

            acceptor.setHandler(new MyServerHandler());

            // 3.设置消息解码器

            acceptor.getFilterChain().addLast("codec", new ProtocolCodecFilter(new MyTextLineFactory()));// acceptor.getSessionConfig().setIdleTime(IdleStatus.BOTH_IDLE, 3);

            // //设置idle时长

            // 4.绑定端口开启服务

            acceptor.bind(new InetSocketAddress(9999));

        } catch (IOException e) {

            e.printStackTrace();

        }

    }

}

/**

 * 专门处理消息的类,实现网络连接和消息处理的解耦

 */

class MyServerHandler extends IoHandlerAdapter {

    /** 异常时候的处理 */

    @Override

    public void exceptionCaught(IoSession session, Throwable cause) throws Exception {

        System.out.println("exceptionCaught");

    }

    /** 收到消息 */

    @Override

    public void messageReceived(IoSession session, Object message) throws Exception {

        System.out.println("messageReceived " + message);

        // session.write("reply " + message); //收到消息就马上把消息回送给客户端

    }

    /** 发送消息 */

    @Override

    public void messageSent(IoSession session, Object message) throws Exception {

        System.out.println("messageSent " + message);

    }

    /** 通讯闲置时候的处理 */

    @Override

    public void sessionIdle(IoSession session, IdleStatus status) throws Exception {

        System.out.println("sessionIdle");

    }

}

package de.bvb.server;

import java.nio.charset.Charset;

import java.nio.charset.CharsetEncoder;

import org.apache.mina.core.buffer.IoBuffer;

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

import org.apache.mina.filter.codec.CumulativeProtocolDecoder;

import org.apache.mina.filter.codec.ProtocolCodecFactory;

import org.apache.mina.filter.codec.ProtocolDecoder;

import org.apache.mina.filter.codec.ProtocolDecoderOutput;

import org.apache.mina.filter.codec.ProtocolEncoder;

import org.apache.mina.filter.codec.ProtocolEncoderOutput;

public class MyTextLineFactory implements ProtocolCodecFactory {

    private ProtocolEncoder encoder;

    private ProtocolDecoder decoder;

    public MyTextLineFactory() {

        encoder = new MyTextLineEncoder();

        decoder = new MyCumulativeProtocolDecoder();

    }

    @Override

    public ProtocolEncoder getEncoder(IoSession session) throws Exception {

        return encoder;

    }

    @Override

    public ProtocolDecoder getDecoder(IoSession session) throws Exception {

        return decoder;

    }

}

class MyTextLineEncoder implements ProtocolEncoder {

    @Override

    public void encode(IoSession session, Object message, ProtocolEncoderOutput out) throws Exception {

        // 编码格式

        CharsetEncoder charsetEncoder = (CharsetEncoder) session.getAttribute("encoder");

        if (charsetEncoder == null) {

            charsetEncoder = Charset.defaultCharset().newEncoder();

            session.setAttribute("encoder", charsetEncoder);

        }

        String value = (message == null ? "" : message.toString());

        IoBuffer buffer = IoBuffer.allocate(value.length()).setAutoExpand(true);

        buffer.putString(value, charsetEncoder);

        buffer.flip();

        out.write(buffer);

    }

    @Override

    public void dispose(IoSession session) throws Exception {

    }

}

class MyCumulativeProtocolDecoder extends CumulativeProtocolDecoder {

    @Override

    protected boolean doDecode(IoSession session, IoBuffer in, ProtocolDecoderOutput out) throws Exception {

        int startPosition = in.position();

        while (in.hasRemaining()) {

            byte b = in.get();

            if (b == '\n') {

                int currentPosition = in.position();

                int limit = in.limit();

                in.position(startPosition);

                in.limit(currentPosition);

                IoBuffer buffer = in.slice();

                byte[] dest = new byte[buffer.limit()];

                buffer.get(dest);

                String str = new String(dest);

                out.write(str);

                in.position(currentPosition);

                in.limit(limit);

                return true;

            }

        }

        in.position(startPosition);

        return false;

    }

}