首先,Mina是个什么东西?看下官方网站(http://mina.apache.org/)对它的解释:
Apache的Mina(Multipurpose Infrastructure Networked Applications)是一个网络应用框架,可以帮助用户开发高性能和高扩展性的网络应用程序;它提供了一个抽象的、事件驱动的异步API,使Java NIO在各种传输协议(如TCP/IP,UDP/IP协议等)下快速高效开发。
Apache Mina也称为:
NIO框架
客户端/服务端框架(典型的C/S架构)
网络套接字(networking socket)类库
事件驱动的异步API(注意:在JDK7中也新增了异步API)
总之:我们简单理解它是一个封装底层IO操作,提供高级操作API的通讯框架!
在Mina的官网、以及网上都有比较丰富的文档了,这里我就稍微简单说一下Mina的结构和示例代码。
因为Mina2.X改进了Mina的代码结构和包结构,降低了使用的复杂性和增强了健壮性,所以使得API发生了比较大的改变,有许多地方已经和Mina1.x不兼容了。
我这里要实现的是在线聊天功能,所以其中使用的数据并不单一,所以这里采用了JOSN的数据格式,我这里是采用UTF-8的编码。
使用的Mina版本为2.0.4
具体的开发过程,比如导包和建立项目什么的我就不说了,这里直接上代码。
(1)服务端代码TcpServer
我这里使用的是Mina自带TextLineCodecFactory
package com.lrcx.ky.server; import java.io.IOException; import java.net.InetSocketAddress; import java.nio.charset.Charset; import java.util.concurrent.Executors; import org.apache.mina.core.service.IoServiceStatistics; import org.apache.mina.core.session.IdleStatus; import org.apache.mina.filter.codec.ProtocolCodecFilter; import org.apache.mina.filter.codec.textline.LineDelimiter; import org.apache.mina.filter.codec.textline.TextLineCodecFactory; import org.apache.mina.filter.executor.ExecutorFilter; import org.apache.mina.transport.socket.SocketAcceptor; import org.apache.mina.transport.socket.nio.NioSocketAcceptor; import com.lrcx.ky.env.SysEnv; public class TcpServer { private int port = 8292; private int idleTime = 1800; private int bufferSize = 1024; private SocketAcceptor acceptor; public void start() { acceptor = new NioSocketAcceptor(Runtime.getRuntime().availableProcessors() + 1); TextLineCodecFactory lineCodec = new TextLineCodecFactory(Charset .forName("UTF-8"), LineDelimiter.WINDOWS.getValue(), LineDelimiter.WINDOWS.getValue()); lineCodec.setDecoderMaxLineLength(2*1024*1024); lineCodec.setEncoderMaxLineLength(2*1024*1024); acceptor.getFilterChain().addLast("codec", new ProtocolCodecFilter(lineCodec)); acceptor.getFilterChain().addLast("exceutor", new ExecutorFilter(Executors.newCachedThreadPool())); acceptor.setHandler(new TcpHandler()); acceptor.setReuseAddress(true); acceptor.setBacklog(10240); acceptor.getSessionConfig().setReuseAddress(true); acceptor.getSessionConfig().setReadBufferSize(bufferSize); acceptor.getSessionConfig().setReceiveBufferSize(bufferSize); acceptor.getSessionConfig().setTcpNoDelay(true); acceptor.getSessionConfig().setSoLinger(-1); // 单位秒 acceptor.getSessionConfig().setIdleTime(IdleStatus.BOTH_IDLE, idleTime); try { acceptor.bind(new InetSocketAddress(port)); } catch (IOException e) { e.printStackTrace(); System.exit(0); } } public void stop() { acceptor.dispose(); } }
代码中的这两行:
lineCodec.setDecoderMaxLineLength(2*1024*1024);
lineCodec.setEncoderMaxLineLength(2*1024*1024);
是用来设置每次传输文本的长度的。
(2)服务端处理器代码TcpHandler
package com.lrcx.ky.server; import net.sf.json.JSONObject; import org.apache.mina.core.service.IoHandlerAdapter; import org.apache.mina.core.session.IdleStatus; import org.apache.mina.core.session.IoSession; public class TcpHandler extends IoHandlerAdapter { @Override public void messageReceived(IoSession session, Object message) throws Exception { JSONObject request = JSONObject.fromObject(message.toString()); // 根据传来的数据进行处理 System.out.println(request); } @Override public void exceptionCaught(IoSession session, Throwable cause) throws Exception { } @Override public void sessionClosed(IoSession session) throws Exception { } @Override public void sessionIdle(IoSession session, IdleStatus status) throws Exception { } }
(3)客户端代码TcpClient
package com.lrcx.ky.site.client; import java.net.InetSocketAddress; import java.nio.charset.Charset; import java.util.concurrent.Executors; import net.sf.json.JSONObject; import org.apache.mina.core.filterchain.DefaultIoFilterChainBuilder; import org.apache.mina.core.future.CloseFuture; import org.apache.mina.core.future.ConnectFuture; import org.apache.mina.core.session.IoSession; import org.apache.mina.filter.codec.ProtocolCodecFilter; import org.apache.mina.filter.codec.textline.LineDelimiter; import org.apache.mina.filter.codec.textline.TextLineCodecFactory; import org.apache.mina.filter.executor.ExecutorFilter; import org.apache.mina.transport.socket.SocketConnector; import org.apache.mina.transport.socket.nio.NioSocketConnector; public class TcpClient { private SocketConnector connector; private ConnectFuture future; private IoSession session; public boolean connect() { try { // 创建一个socket连接 connector = new NioSocketConnector(); // 设置链接超时时间 connector.setConnectTimeoutMillis(3000); // 获取过滤器链 DefaultIoFilterChainBuilder filterChain = connector.getFilterChain(); // 添加编码过滤器 处理乱码、编码问题 TextLineCodecFactory lineCodec = new TextLineCodecFactory(Charset.forName("UTF-8"), LineDelimiter.WINDOWS.getValue(), LineDelimiter.WINDOWS.getValue()); lineCodec.setDecoderMaxLineLength(2*1024*1024); lineCodec.setEncoderMaxLineLength(2*1024*1024); filterChain.addLast("codec", new ProtocolCodecFilter(lineCodec)); filterChain.addLast("exceutor", new ExecutorFilter(Executors.newCachedThreadPool())); // 消息核心处理器 connector.setHandler(new TcpHandler()); // 连接服务器,知道端口、地址 future = connector.connect(new InetSocketAddress("127.0.0.1", 8292)); // 等待连接创建完成 future.awaitUninterruptibly(); // 获取当前session session = future.getSession(); return true; } catch (Exception e) { e.printStackTrace(); return false; } } public void write(JSONObject request) throws Exception { session.write(request.toString()); } public boolean close() { try { CloseFuture future = session.getCloseFuture(); future.awaitUninterruptibly(1000); connector.dispose(); return true; } catch (Exception e) { e.printStackTrace(); return false; } } }
(4)客户端处理器代码TcpHandler
package com.lrcx.ky.site.client; import net.sf.json.JSONObject; import org.apache.mina.core.service.IoHandlerAdapter; import org.apache.mina.core.session.IoSession; public class TcpHandler extends IoHandlerAdapter { public void messageReceived(IoSession session, Object message) throws Exception { JSONObject request = JSONObject.fromObject(message.toString()); // 根据传来的数据进行处理 System.out.println(request); } public void exceptionCaught(IoSession session, Throwable cause) throws Exception { } public void sessionClosed(IoSession session) throws Exception { } }
以上是客户端和服务端通信的基础代码,具体的业务逻辑大家可以在这个基础上随意发挥。