最近使用Mina開發一個在線聊天的項目,因此也特意學習了Apache的這個Mina框架。
首先,Mina是個什麼東西?看下官方網站(http://mina.apache.org/)對它的解釋:
Apache的Mina(Multipurpose Infrastructure Networked Applications)是一個網絡應用框架,可以幫助用戶開發高性能和高擴展性的網絡應用程序;它提供了一個抽象的、事件驅動的異步API,使Java NIO在各種傳輸協議(如TCP/IP,UDP/IP協議等)下快速高效開發。
Apache Mina也稱爲:
- NIO框架
- 客戶端/服務端框架(典型的C/S架構)
- 網絡套接字(networking socket)類庫
- 事件驅動的異步API(注意:在JDK7中也新增了異步API)
總之:我們簡單理解它是一個封裝底層IO操作,提供高級操作API的通訊框架!
在Mina的官網、以及網上都有比較豐富的文檔了,這裏我就稍微簡單說一下Mina的結構和示例代碼。
因爲Mina2.X改進了Mina的代碼結構和包結構,降低了使用的複雜性和增強了健壯性,所以使得API發生了比較大的改變,有許多地方已經和Mina1.x不兼容了。
我這裏要實現的是在線聊天功能,所以其中使用的數據並不單一,所以這裏採用了JOSN的數據格式,我這裏是採用UTF-8的編碼,代碼中用到的JSON的2個處理包:json-lib-2.3-jdk15.jar、ezmorph-1.0.6.jar。
使用的Mina版本爲2.0.4
具體的開發過程,比如導包和建立項目什麼的我就不說了,這裏直接上代碼。
(1)服務端代碼TcpServer
我這裏使用的是Mina自帶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;
- 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);
- // 單位秒
- 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();
- }
- }
代碼中的這兩行:
lineCodec.setDecoderMaxLineLength(2*1024*1024);
lineCodec.setEncoderMaxLineLength(2*1024*1024);
是用來設置每次傳輸文本的長度的。
(2)服務端處理器代碼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());
- // 根據傳來的數據進行處理
- 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)客戶端代碼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 {
- // 創建一個socket連接
- connector = new NioSocketConnector();
- // 設置鏈接超時時間
- connector.setConnectTimeoutMillis(3000);
- // 獲取過濾器鏈
- DefaultIoFilterChainBuilder filterChain = connector.getFilterChain();
- // 添加編碼過濾器 處理亂碼、編碼問題
- 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()));
- // 消息核心處理器
- connector.setHandler(new TcpHandler());
- // 連接服務器,知道端口、地址
- future = connector.connect(new InetSocketAddress("127.0.0.1", 8292));
- // 等待連接創建完成
- future.awaitUninterruptibly();
- // 獲取當前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)客戶端處理器代碼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());
- // 根據傳來的數據進行處理
- System.out.println(request);
- }
- public void exceptionCaught(IoSession session, Throwable cause)
- throws Exception {
- }
- public void sessionClosed(IoSession session) throws Exception {
- }
- }
以上是客戶端和服務端通信的基礎代碼,具體的業務邏輯大家可以在這個基礎上隨意發揮。