java-通讯stocket插件mina实例

mina是对nio的具体实现。是目前比较高效和流行的nio(非阻塞式I/O)框架

mina主要包括：

其中服务端为：NioSocketAcceptor
客户端为：NioSocketConnector

使用mina进行一个简单的客户端上传文件的demo的实现：

demo实现的思想为：

客 户端跟服务端建立起来连接，客户端每次想服务端传输一定大小的文件内容。(byte的方式)，然后服务端接收这些byte，将其output出来，形成文 件。客户端发送完毕后，传递一个完毕的标志，这里可以传个字符串”finish“，然后服务器收到这个结束标志，在写文件结束后，再传输个成功的标志给客 户端，(字符串”success“)然后客户端关闭连接。

服务端：

代码比较简单。

import java.net.InetSocketAddress;
import org.apache.mina.filter.codec.ProtocolCodecFilter;
import org.apache.mina.filter.codec.serialization.ObjectSerializationCodecFactory;
import org.apache.mina.filter.logging.LoggingFilter;
import org.apache.mina.transport.socket.nio.NioSocketAcceptor;

public class Main {
 private static final int PORT = 8080;

 public static void main(String[] args) throws Exception {
 //服务端的实例
 NioSocketAcceptor accept=new NioSocketAcceptor();
 //添加filter，codec为序列化方式。这里为对象序列化方式，即表示传递的是对象。
 accept.getFilterChain().addLast("codec",
 new ProtocolCodecFilter(new ObjectSerializationCodecFactory()));
                //添加filter，日志信息
 accept.getFilterChain().addLast("logging", new LoggingFilter());
 //设置服务端的handler
 accept.setHandler(new FileUploadHandler());
 //绑定ip
 accept.bind(new InetSocketAddress(PORT));

        System.out.println("upload  server started.");
 }
}

服务端的handler。

import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.mina.core.service.IoHandlerAdapter;
import org.apache.mina.core.session.IoSession;

public class FileUploadHandler extends IoHandlerAdapter {

 private BufferedOutputStream out;

 private int count;

 private String fileName = "D:/log/test.jpg";

 private static final Log log = LogFactory.getLog(FileUploadHandler.class);

 public void sessionOpened(IoSession session) throws Exception {
 System.out.println("server open");
 }

 public void exceptionCaught(IoSession session, Throwable cause)
 throws Exception {
 System.out.println("exception");
 session.close(true);
 super.exceptionCaught(session, cause);
 }

 public void messageReceived(IoSession session, Object message) {
 System.out.println("server received");

 try {
 if (message instanceof FileUploadRequest) {
                 //FileUploadRequest 为传递过程中使用的DO。
 FileUploadRequest request = (FileUploadRequest) message;
 System.out.println(request.getFilename());
 if (out == null) {
 //新建一个文件输入对象BufferedOutputStream，随便定义新文件的位置
 out = new BufferedOutputStream(new FileOutputStream(
 "D:/log/" + request.getFilename()));
 out.write(request.getFileContent());
 } else {
 out.write(request.getFileContent());
 }
 count += request.getFileContent().length;

 } else if (message instanceof String) {
 if (((String)message).equals("finish")) {
 System.out.println("size is"+count);
 //这里是进行文件传输后，要进行flush和close否则传递的文件不完整。
 out.flush();
 out.close();
 //回执客户端信息，上传文件成功
 session.write("success");
 }
 }

 } catch (Exception e) {
 e.printStackTrace();
 }
 }

 public void sessionClosed(IoSession session) throws Exception {
 System.out.println("server session close");
 }
}

所有的handler都要继承IoHandlerAdapter，可以查看IoHandlerAdapter，其包括几个关于session状态的方法。按需进行重载即可。

然后就是公用的用来传输的DO：FileUploadRequest简单的POJO

import java.io.Serializable;

public class FileUploadRequest implements Serializable {
 private String hostname;
 private String filename;
 private byte[] fileContent;

 public String getHostname() {
 return hostname;
 }

 public void setHostname(String hostname) {
 this.hostname = hostname;
 }

 public String getFilename() {
 return filename;
 }

 public void setFilename(String filename) {
 this.filename = filename;
 }

 public byte[] getFileContent() {
 return fileContent;
 }

 public void setFileContent(byte[] fileContent) {
 this.fileContent = fileContent;
 }
}

接下来看下客户端的实现，也很简单：

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.net.InetSocketAddress;
import nio.upload.server.FileUploadRequest;
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.serialization.ObjectSerializationCodecFactory;
import org.apache.mina.filter.logging.LoggingFilter;
import org.apache.mina.transport.socket.nio.NioSocketConnector;

public class MainClient {

 private static final int PORT = 8080;

 /**
  * @param args
  * @throws IOException
  */
 public static void main(String[] args) throws Exception {
 //客户端的实现
 NioSocketConnector connector = new NioSocketConnector();
 connector.getFilterChain().addLast("codec",
 new ProtocolCodecFilter(new ObjectSerializationCodecFactory()));
 connector.getFilterChain().addLast("logging", new LoggingFilter());
 FileUploadClientHandler h = new FileUploadClientHandler();
 connector.setHandler(h);
 //本句需要加上，否则无法调用下面的readFuture来从session中读取到服务端返回的信息。
 connector.getSessionConfig().setUseReadOperation(true);

 ConnectFuture cf = connector.connect(new InetSocketAddress("localhost",
 PORT));

 IoSession session;
 //等待连接成功
 cf.awaitUninterruptibly();
 session = cf.getSession();

 System.out.println("client send begin");

 //传递文件开始
 String fileName = "test.jpg";
 FileInputStream fis = new FileInputStream(new File(fileName));
 byte[] a = new byte[1024 * 4];
 FileUploadRequest request = new FileUploadRequest();
 request.setFilename(fileName);
 request.setHostname("localhost");
 while (fis.read(a, 0, a.length) != -1) {
 request.setFileContent(a);
 //像session中写入信息供服务端获得
 session.write(request);
 }
 //发送完成的标志
 session.write(new String("finish"));

 System.out.println("client send finished and wait success");
 //接上面来取得服务端的信息
 Object result = session.read().awaitUninterruptibly().getMessage();
 if (result.equals("success")) {
 System.out.println("success!");
 //关闭客户端
 connector.dispose();
 }
 }
}

客户端handler的实现。

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

public class FileUploadClientHandler extends IoHandlerAdapter {

 public void sessionOpened(IoSession session) throws Exception {
 System.out.println("client open");
 }

 public void sessionClosed(IoSession session) throws Exception {
 System.out.println("client session close");
 }

 public void messageReceived(IoSession session, Object message)
 throws Exception {
 System.out.println("thr result is" + message);
 }
}

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