Mina - 模拟同步请求

这篇博客主要就铺代码吧，Mina的一些基础知识可以参考：

http://www.cnblogs.com/huangfox/p/3458272.html

场景假设：

1.客户端发送用户信息，服务端根据用户名查询用户年龄。（模拟查询）

2.同步请求

3.协议：直接采用字段类型编码解码。

---

具体代码结构：

codec负责编码解码，TCPAcceptor服务端，TCPConnector客户端，User业务对象。

---

User

package com.fox.mina.base.c2;

/**
 * @author huangfox
 * @date 2013年12月3日 上午11:23:55
 *
 */
public class User {
	String name;
	int age;

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	public int getAge() {
		return age;
	}

	public void setAge(int age) {
		this.age = age;
	}

	@Override
	public String toString() {
		return "User [name=" + name + ", age=" + age + "]";
	}

}

　　

编码、解码工厂

DefaultMinaCodecFactory

package com.fox.mina.base.c2.codec;

import org.apache.mina.core.session.IoSession;
import org.apache.mina.filter.codec.ProtocolCodecFactory;
import org.apache.mina.filter.codec.ProtocolDecoder;
import org.apache.mina.filter.codec.ProtocolEncoder;

/**
 * @author huangfox
 * @date 2013年12月5日 下午7:48:47
 *
 */
public class DefaultMinaCodecFactory implements ProtocolCodecFactory {
	ProtocolEncoder encoder;
	ProtocolDecoder decoder;

	public DefaultMinaCodecFactory() {

	}

	public DefaultMinaCodecFactory(ProtocolEncoder encoder,
			ProtocolDecoder decoder) {
		super();
		this.encoder = encoder;
		this.decoder = decoder;
	}

	@Override
	public ProtocolEncoder getEncoder(IoSession session) throws Exception {
		// TODO Auto-generated method stub
		return encoder;
	}

	@Override
	public ProtocolDecoder getDecoder(IoSession session) throws Exception {
		// TODO Auto-generated method stub
		return decoder;
	}

	public ProtocolEncoder getEncoder() {
		return encoder;
	}

	public void setEncoder(ProtocolEncoder encoder) {
		this.encoder = encoder;
	}

	public ProtocolDecoder getDecoder() {
		return decoder;
	}

	public void setDecoder(ProtocolDecoder decoder) {
		this.decoder = decoder;
	}

}

　　

编码器

FEncode

package com.fox.mina.base.c2.codec;

import org.apache.commons.lang.ArrayUtils;
import org.apache.mina.core.buffer.IoBuffer;
import org.apache.mina.core.session.IoSession;
import org.apache.mina.filter.codec.ProtocolEncoderAdapter;
import org.apache.mina.filter.codec.ProtocolEncoderOutput;

import com.fox.mina.base.c2.User;

/**
 * @author huangfox
 * @date 2013年12月5日 下午7:49:21
 *
 */
public class FEncoder extends ProtocolEncoderAdapter {
	public static final NumberCodec numberCodec = DefaultNumberCodecs
			.getBigEndianNumberCodec();

	@Override
	public void encode(IoSession session, Object message,
			ProtocolEncoderOutput out) throws Exception {
		byte[] bytes = null;
		if (message instanceof User) {
			User user = (User) message;
			byte[] name = user.getName().getBytes();
			bytes = ArrayUtils.addAll(bytes,
					numberCodec.int2Bytes(name.length, 4));
			bytes = ArrayUtils.addAll(bytes, name);
			bytes = ArrayUtils.addAll(bytes,
					numberCodec.int2Bytes(user.getAge(), 4));
			out.write(IoBuffer.wrap(bytes));
		} else {
			System.out.println("encoder error!");
		}

	}

}

编码的协议：

用户姓名的长度（int 4字节）

用户年龄（int 4字节）

用户姓名（byte[]）

解码器

FDecode

package com.fox.mina.base.c2.codec;

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.ProtocolDecoderOutput;

import com.fox.mina.base.c2.User;

/**
 * @author huangfox
 * @date 2013年12月3日 上午11:35:46
 *
 */
public class FDecoder extends CumulativeProtocolDecoder {
	public static final NumberCodec numberCodec = DefaultNumberCodecs
			.getBigEndianNumberCodec();

	@Override
	protected boolean doDecode(IoSession session, IoBuffer in,
			ProtocolDecoderOutput out) throws Exception {
		int len = 0;
		Object lenAttr = session.getAttribute("len");
		if (lenAttr == null) {
			if (in.remaining() < 4) {
				return false;
			}
			byte[] buffer = new byte[4];
			in.get(buffer);
			len = numberCodec.bytes2Int(buffer, 4);
			session.setAttribute("len", len);
		} else {
			len = (Integer) lenAttr;
		}
		//
		String name = "";
		Object nameAttr = session.getAttribute("name");
		if (nameAttr == null) {
			if (in.remaining() < len) {
				return false;
			}
			byte[] buffer = new byte[len];
			in.get(buffer);
			name = new String(buffer);
			session.setAttribute("name", name);
		} else {
			name = (String) nameAttr;
		}
		if (in.remaining() < 4) {
			return false;
		}
		byte[] buffer = new byte[4];
		in.get(buffer);
		int age = numberCodec.bytes2Int(buffer, 4);
		User u = new User();
		u.setName(name);
		u.setAge(age);
		//
		out.write(u);
		//
		session.removeAttribute("len");
		session.removeAttribute("name");

		return true;
	}

}

编码、解码使用的工具类：

package com.fox.mina.base.c2.codec;

public interface NumberCodec {
	String convertCharset(String charset);

	byte[] short2Bytes(short value, int byteLength);

	byte[] int2Bytes(int value, int byteLength);

	byte[] long2Bytes(long value, int byteLength);

	byte[] float2Bytes(float value, int byteLength);

	byte[] double2Bytes(double value, int byteLength);

	short bytes2Short(byte[] bytes, int byteLength);

	int bytes2Int(byte[] bytes, int byteLength);

	long bytes2Long(byte[] bytes, int byteLength);

	float bytes2Float(byte[] bytes, int byteLength);

	double bytes2Double(byte[] bytes, int byteLength);
}

　　

package com.fox.mina.base.c2.codec;

public class DefaultNumberCodecs {

	private static int b2ui(byte b) {
		return (int) (b + 256) % 256;
	}

	private static long b2ul(byte b) {
		return (long) (b + 256) % 256;
	}

	private static NumberCodec littleEndianCodec = new NumberCodec() {

		public int bytes2Int(byte[] bytes, int byteLength) {
			int value = 0;
			for (int i = 0; i < byteLength; i++) {
				value |= b2ui(bytes[i]) << (i * 8);
			}
			return value;
		}

		public long bytes2Long(byte[] bytes, int byteLength) {
			long value = 0;
			for (int i = 0; i < byteLength; i++) {
				value |= b2ul(bytes[i]) << (i * 8);
			}

			return value;
		}

		public short bytes2Short(byte[] bytes, int byteLength) {
			short value = 0;
			for (int i = 0; i < byteLength; i++) {
				value |= b2ui(bytes[i]) << (i * 8);
			}

			return value;
		}

		@Override
		public float bytes2Float(byte[] bytes, int byteLength) {
			int value = 0;
			for (int i = 0; i < byteLength; i++) {
				value |= b2ui(bytes[i]) << (i * 8);
			}
			return Float.intBitsToFloat(value);
		}

		@Override
		public double bytes2Double(byte[] bytes, int byteLength) {
			long value = 0;
			for (int i = 0; i < byteLength; i++) {
				value |= b2ul(bytes[i]) << (i * 8);
			}
			return Double.longBitsToDouble(value);
		}

		public byte[] int2Bytes(int value, int byteLength) {
			byte[] bytes = new byte[byteLength];

			for (int i = 0; i < byteLength; i++) {
				int shiftCount = i * 8;
				bytes[i] = (byte) ((value & (0x000000ff << shiftCount)) >> shiftCount);
			}
			return bytes;
		}

		public byte[] long2Bytes(long value, int byteLength) {
			byte[] bytes = new byte[byteLength];

			for (int i = 0; i < byteLength; i++) {
				int shiftCount = i * 8;
				bytes[i] = (byte) ((value & (0x00000000000000ffL << shiftCount)) >> shiftCount);
			}
			return bytes;
		}

		public byte[] short2Bytes(short value, int byteLength) {
			byte[] bytes = new byte[byteLength];

			for (int i = 0; i < byteLength; i++) {
				int shiftCount = i * 8;
				bytes[i] = (byte) ((value & (0x00ff << shiftCount)) >> shiftCount);
			}
			return bytes;
		}

		@Override
		public byte[] float2Bytes(float value, int byteLength) {
			byte[] bytes = new byte[byteLength];

			// parse the bits that represent the floating-point number
			// floatToRawIntBits gives the raw float bits without normalization
			// using floatToRawIntBits is over 5 times as fast as
			// floatToIntBits.
			int x = Float.floatToRawIntBits(value);
			for (int i = 0; i < byteLength; i++) {
				int shiftCount = i * 8;
				bytes[i] = (byte) ((x & (0x000000ff << shiftCount)) >> shiftCount);
			}
			return bytes;
		}

		@Override
		public byte[] double2Bytes(double value, int byteLength) {
			byte[] bytes = new byte[byteLength];

			// parse the the bits that represent the floating-point number
			long x = Double.doubleToRawLongBits(value);
			for (int i = 0; i < byteLength; i++) {
				int shiftCount = i * 8;
				bytes[i] = (byte) ((x & (0x00000000000000ffL << shiftCount)) >> shiftCount);
			}
			return bytes;
		}

		public String convertCharset(String charset) {
			if (charset.equals("UTF-16")) {
				return "UTF-16LE";
			} else {
				return charset;
			}
		}

	};

	private static NumberCodec bigEndianCodec = new NumberCodec() {

		public int bytes2Int(byte[] bytes, int byteLength) {
			int value = 0;
			for (int i = 0; i < byteLength; i++) {
				value |= b2ui(bytes[i]) << ((byteLength - 1 - i) * 8);
			}
			return value;
		}

		public long bytes2Long(byte[] bytes, int byteLength) {
			long value = 0;
			for (int i = 0; i < byteLength; i++) {
				value |= b2ul(bytes[i]) << ((byteLength - 1 - i) * 8);
			}

			return value;
		}

		public short bytes2Short(byte[] bytes, int byteLength) {
			short value = 0;
			for (int i = 0; i < byteLength; i++) {
				value |= b2ui(bytes[i]) << ((byteLength - 1 - i) * 8);
			}

			return value;
		}

		@Override
		public float bytes2Float(byte[] bytes, int byteLength) {
			int value = 0;
			for (int i = 0; i < byteLength; i++) {
				value |= b2ui(bytes[i]) << ((byteLength - 1 - i) * 8);
			}
			return Float.intBitsToFloat(value);
		}

		@Override
		public double bytes2Double(byte[] bytes, int byteLength) {
			long value = 0;
			for (int i = 0; i < byteLength; i++) {
				value |= b2ul(bytes[i]) << ((byteLength - 1 - i) * 8);
			}
			return Double.longBitsToDouble(value);
		}

		public byte[] int2Bytes(int value, int byteLength) {
			byte[] bytes = new byte[byteLength];

			for (int i = 0; i < byteLength; i++) {
				int shiftCount = ((byteLength - 1 - i) * 8);
				bytes[i] = (byte) ((value & (0x000000ff << shiftCount)) >> shiftCount);
			}
			return bytes;
		}

		public byte[] long2Bytes(long value, int byteLength) {
			byte[] bytes = new byte[byteLength];

			for (int i = 0; i < byteLength; i++) {
				int shiftCount = ((byteLength - 1 - i) * 8);
				bytes[i] = (byte) ((value & (0x00000000000000ffL << shiftCount)) >> shiftCount);
			}
			return bytes;
		}

		public byte[] short2Bytes(short value, int byteLength) {
			byte[] bytes = new byte[byteLength];

			for (int i = 0; i < byteLength; i++) {
				int shiftCount = ((byteLength - 1 - i) * 8);
				bytes[i] = (byte) ((value & (0x00ff << shiftCount)) >> shiftCount);
			}
			return bytes;
		}

		@Override
		public byte[] float2Bytes(float value, int byteLength) {
			byte[] bytes = new byte[byteLength];

			// parse the bits that represent the floating-point number
			// floatToRawIntBits gives the raw float bits without normalization
			// using floatToRawIntBits is over 5 times as fast as
			// floatToIntBits.
			int x = Float.floatToRawIntBits(value);
			for (int i = 0; i < byteLength; i++) {
				int shiftCount = ((byteLength - 1 - i) * 8);
				bytes[i] = (byte) ((x & (0x000000ffL << shiftCount)) >> shiftCount);
			}
			return bytes;
		}

		@Override
		public byte[] double2Bytes(double value, int byteLength) {
			byte[] bytes = new byte[byteLength];

			// parse the the bits that represent the floating-point number
			long x = Double.doubleToRawLongBits(value);
			for (int i = 0; i < byteLength; i++) {
				int shiftCount = ((byteLength - 1 - i) * 8);
				bytes[i] = (byte) ((x & (0x00000000000000ffL << shiftCount)) >> shiftCount);
			}
			return bytes;
		}

		public String convertCharset(String charset) {
			if (charset.equals("UTF-16")) {
				return "UTF-16BE";
			} else {
				return charset;
			}
		}

	};

	public static NumberCodec getBigEndianNumberCodec() {
		return bigEndianCodec;
	}

	public static NumberCodec getLittleEndianNumberCodec() {
		return littleEndianCodec;
	}
}

　　

服务端

TCPAcceptor

package com.fox.mina.base.c2;

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

import org.apache.mina.core.service.IoAcceptor;
import org.apache.mina.core.service.IoHandlerAdapter;
import org.apache.mina.core.session.IoSession;
import org.apache.mina.core.session.IoSessionConfig;
import org.apache.mina.filter.codec.ProtocolCodecFilter;
import org.apache.mina.transport.socket.nio.NioSocketAcceptor;

import com.fox.mina.base.c2.codec.DefaultMinaCodecFactory;
import com.fox.mina.base.c2.codec.FDecoder;
import com.fox.mina.base.c2.codec.FEncoder;

/**
 * @author huangfox
 * @date 2013年12月3日 上午11:15:53
 *
 */
public class TCPAcceptor {
	IoAcceptor acceptor = null;
	String addr = "127.0.0.1";
	int port = 9999;

	public TCPAcceptor() {

	}

	public void start() {
		acceptor = new NioSocketAcceptor();
		//
		IoSessionConfig sessionConf = acceptor.getSessionConfig();
		sessionConf.setReadBufferSize(2048);
		// filter chain(codec)
		acceptor.getFilterChain().addLast(
				"codec",
				new ProtocolCodecFilter(new DefaultMinaCodecFactory(
						new FEncoder(), new FDecoder())));
		// handler
		acceptor.setHandler(new IOHandler());
		//
		try {// 可做重连
			acceptor.bind(new InetSocketAddress(addr, port));
		} catch (IOException e) {
			e.printStackTrace();
		}
		System.out.println("server stated ... ");
	}

	private class IOHandler extends IoHandlerAdapter {

		@Override
		public void messageReceived(IoSession session, Object message)
				throws Exception {
			User u = (User) message;
			System.out.println("[server]" + u.toString());
			//模拟业务处理
			u.setAge(u.hashCode()%100);
			// send msg to client
			session.write(u);
		}

	}

	public static void main(String[] args) {
		TCPAcceptor server = new TCPAcceptor();
		server.start();
	}

}

　　

客户端

TCPConnector

package com.fox.mina.base.c2;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.InetSocketAddress;
import java.util.Random;

import org.apache.mina.core.future.ConnectFuture;
import org.apache.mina.core.future.ReadFuture;
import org.apache.mina.core.future.WriteFuture;
import org.apache.mina.core.service.IoConnector;
import org.apache.mina.core.service.IoHandlerAdapter;
import org.apache.mina.core.session.IoSession;
import org.apache.mina.filter.codec.ProtocolCodecFilter;
import org.apache.mina.transport.socket.nio.NioSocketConnector;

import com.fox.mina.base.c2.codec.DefaultMinaCodecFactory;
import com.fox.mina.base.c2.codec.FDecoder;
import com.fox.mina.base.c2.codec.FEncoder;

/**
 * @author huangfox
 * @date 2013年12月3日 上午11:15:46
 *
 */
public class TCPConnector {
	IoConnector connector = null;
	IoSession session = null;
	String ip = "127.0.0.1";
	int port = 9999;

	public TCPConnector() {
		connector = new NioSocketConnector();
		connector.getSessionConfig().setUseReadOperation(true);
		connector.getFilterChain().addLast(
				"codec",
				new ProtocolCodecFilter(new DefaultMinaCodecFactory(
						new FEncoder(), new FDecoder())));
		connector.setHandler(new IOHander());
		ConnectFuture connectF = connector.connect(new InetSocketAddress(ip,
				port));
		connectF.awaitUninterruptibly();
		session = connectF.getSession();
	}

	Random r = new Random();

	public void sendMsg(User u) {
		WriteFuture writeF = session.write(u);
		writeF.awaitUninterruptibly();
		if (writeF.getException() != null) {
			System.out.println(writeF.getException().getMessage());
		} else if (writeF.isWritten()) {
			System.out.println("msg was sent!");
			// 发送、接受
			ReadFuture readF = session.read();
			readF.awaitUninterruptibly(1000);
			if (readF.getException() != null) {
				System.out.println(readF.getException().getMessage());
			} else {
				System.out.println("[client]"+readF.getMessage().toString());
			}
		} else {
			System.out.println("error!");
		}
	}

	public void close() {
		this.connector.dispose();
	}

	private class IOHander extends IoHandlerAdapter {

	}

	public static void main(String[] args) {
		TCPConnector client = new TCPConnector();
		while (true) {
			BufferedReader r = new BufferedReader(new InputStreamReader(
					System.in));
			try {
				System.out.println("输入：");
				String msg = r.readLine();
				User u = new User();
				u.setName(msg);
				client.sendMsg(u);
			} catch (IOException e) {
				e.printStackTrace();
			}

		}
	}

}

---

注意：以上代码在多线程环境下是有问题的！！！　　

（最大字体的提示了！）

在TcpConnector中，只有一个session，如果多线程同时对这个session进行读写操作将发生问题（B可能拿到A的响应结果）。

最简单的处理方式就是，加入一个连接池，在sendMsg方法中先获取一个连接，用完以后再归还到连接池。可以理解为“一个线程独占一个连接”。

代码如下：

package com.fox.mina.base.c2;

import java.net.InetSocketAddress;
import java.util.Date;
import java.util.Random;
import java.util.concurrent.LinkedBlockingQueue;
import java.util.concurrent.TimeUnit;

import org.apache.mina.core.future.ConnectFuture;
import org.apache.mina.core.future.ReadFuture;
import org.apache.mina.core.future.WriteFuture;
import org.apache.mina.core.service.IoConnector;
import org.apache.mina.core.service.IoHandlerAdapter;
import org.apache.mina.core.session.IoSession;
import org.apache.mina.filter.codec.ProtocolCodecFilter;
import org.apache.mina.transport.socket.nio.NioSocketConnector;

import com.fox.mina.base.c2.codec.DefaultMinaCodecFactory;
import com.fox.mina.base.c2.codec.FDecoder;
import com.fox.mina.base.c2.codec.FEncoder;

/**
 * @author huangfox
 * @date 2013年12月3日 上午11:15:46
 *
 */
public class TCPConnector {
	IoConnector connector = null;
	// IoSession session = null;
	String ip = "127.0.0.1";
	int port = 9999;
	int poolSize = 1;
	LinkedBlockingQueue<IoSession> pool;

	public TCPConnector() {
		connector = new NioSocketConnector(10);
		connector.getSessionConfig().setUseReadOperation(true);
		connector.getFilterChain().addLast(
				"codec",
				new ProtocolCodecFilter(new DefaultMinaCodecFactory(
						new FEncoder(), new FDecoder())));
		connector.setHandler(new IOHander());
		// pool
		pool = new LinkedBlockingQueue<IoSession>(poolSize);
		for (int i = 0; i < poolSize; i++) {
			ConnectFuture connectF = connector.connect(new InetSocketAddress(
					ip, port));
			connectF.awaitUninterruptibly();
			IoSession session = connectF.getSession();
			try {
				pool.put(session);
			} catch (InterruptedException e) {
				e.printStackTrace();
			}
		}
	}

	Random r = new Random();

	public void sendMsg(User u) {
		IoSession session = null;
		try {
			session = pool.take();
		} catch (InterruptedException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		if (session == null)
			return;
		try {
			WriteFuture writeF = session.write(u);
			writeF.awaitUninterruptibly();
			if (writeF.getException() != null) {
				System.out.println(writeF.getException().getMessage());
			} else if (writeF.isWritten()) {
				// System.out.println("msg was sent!");
				// 发送、接受
				ReadFuture readF = session.read();
				readF.awaitUninterruptibly();
				if (readF.getException() != null) {
					System.out.println(readF.getException().getMessage());
				} else {
					Date d = new Date(System.currentTimeMillis());
					// System.out.println(Thread.currentThread().getId() + "-"
					// + d.getSeconds() + "-" + session.hashCode());
					// System.out.println("[client]"
					// + readF.getMessage().toString());
				}
			} else {
				System.out.println("error!");
			}
		} finally {
			try {
				pool.put(session);
			} catch (InterruptedException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
	}

	public void close() {
		this.connector.dispose();
	}

	private class IOHander extends IoHandlerAdapter {

	}

}

　　

---

扩展：

1.加入连接池（见上文）

2.加入连接、读写超时