Socket编程及mina框架简单示例
要实现客户端与服务器的长连接，可以使用socket的方式连接服务器与客户端。在这篇文章中，将用原生的方式实现socket的服务器端和客户端，然后用Mina框架再实现一次。
原生方式上：
客户端可实现如下：
SocketClient:
package socketClient;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.net.Socket;
public class SocketClient {
public int port = 9898;
public String hostAddress = "127.0.0.1";
public static void main(String[] args) {
SocketClient client = new SocketClient();
client.start();
}
private void start() {
BufferedReader inputReader = null;
OutputStreamWriter output = null;
Socket socket = null;
try {
socket = new Socket(hostAddress, port);
inputReader = new BufferedReader(new InputStreamReader(System.in));
output = new OutputStreamWriter(socket.getOutputStream());
String inputContent;
int count = 0;
while (!(inputContent = inputReader.readLine()).equals("bye")) {
output.write(inputContent);
output.write("\n");
output.flush();
getServerMsg(socket);
}
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
output.close();
inputReader.close();
socket.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
private void getServerMsg(Socket socket) {
new Thread(new Runnable() {
@Override
public void run() {
BufferedReader reader = null;
try {
reader = new BufferedReader(new InputStreamReader(
socket.getInputStream()));
String serverMsg;
while ((serverMsg = reader.readLine()) != null) {
System.out.println("server say: " + serverMsg);
}
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
reader.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}).start();
}
}
服务器端：
package com.socket.tra;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.net.ServerSocket;
import java.net.Socket;
public class SocketServer {
public static void main(String[] args) {
SocketServer server = new SocketServer();
server.startServer();
}
private void startServer() {
ServerSocket serverSocket = null;
Socket socket = null;
try {
serverSocket = new ServerSocket(9898);
while (true) {
socket = serverSocket.accept();
System.out.println(socket.hashCode() + " is connect");
connect(socket);
}
} catch (IOException e) {
e.printStackTrace();
}
}
private void connect(final Socket socket) {
new Thread(new Runnable() {
public void run() {
BufferedReader reader = null;
OutputStreamWriter writer = null;
try {
reader = new BufferedReader(new InputStreamReader(
socket.getInputStream()));
writer = new OutputStreamWriter(socket.getOutputStream());
String msg;
while ((msg = reader.readLine()) != null) {
System.out.println(socket.hashCode()+"say: "+msg);
writer.write(msg + "\n");
writer.flush();
}
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
writer.close();
reader.close();
socket.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}).start();
}
}
这是socket基本的用法，但在实际开发中，我们一般用封装好的框架来实现，Apache mina就是能够帮助用户开发高性能和高伸缩性网络应用程序的框架。它通过Java nio技术基于TCP/IP和UDP/IP协议提供了抽象的、事件驱动的、异步的API。
具体用法可以去官网了解下，这里提供一个简单的使用示例，实现跟上面原生方法同样的功能。
版本一：
服务器端:
package com.socket;
import java.io.IOException;
import java.net.InetSocketAddress;
import org.apache.mina.filter.codec.ProtocolCodecFilter;
import org.apache.mina.filter.codec.textline.TextLineCodecFactory;
import org.apache.mina.transport.socket.nio.NioSocketAcceptor;
public class Main {
public static int port = 9898;
public static void main(String[] args) {
NioSocketAcceptor acceptor = new NioSocketAcceptor();
try {
//设置handler
acceptor.setHandler(new MyHandler());
//设置过滤器
acceptor.getFilterChain().addLast("codec", new ProtocolCodecFilter(new TextLineCodecFactory()));
//绑定端口号
acceptor.bind(new InetSocketAddress(port));
} catch (IOException e) {
e.printStackTrace();
}
}
}MyHandler:
package com.socket;
import org.apache.mina.core.service.IoHandler;
import org.apache.mina.core.session.IdleStatus;
import org.apache.mina.core.session.IoSession;
public class MyHandler implements IoHandler {
public void exceptionCaught(IoSession arg0, Throwable arg1)
throws Exception {
System.out.println("exception");
}
public void inputClosed(IoSession arg0) throws Exception {
System.out.println("inputClosed");
}
public void messageReceived(IoSession arg0, Object arg1) throws Exception {
String msg = (String) arg1;
System.out.println("messageReceived server: " + msg);
arg0.write(msg);
}
public void messageSent(IoSession arg0, Object arg1) throws Exception {
System.out.println("messageSent");
}
public void sessionClosed(IoSession arg0) throws Exception {
System.out.println("sessionClosed "+arg0.hashCode());
}
public void sessionCreated(IoSession arg0) throws Exception {
System.out.println("sessionCreated "+arg0.hashCode());
}
public void sessionIdle(IoSession arg0, IdleStatus arg1) throws Exception {
System.out.println("sessionIdle "+arg0.hashCode()+" , "+arg1);
}
public void sessionOpened(IoSession arg0) throws Exception {
System.out.println("sessionOpened "+arg0.hashCode());
}
}
客户端：
package socketClient.mina;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.net.InetSocketAddress;
import java.net.Socket;
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.TextLineCodecFactory;
import org.apache.mina.transport.socket.nio.NioSocketConnector;
public class SocketClient {
public int port = 9898;
public String hostAddress = "127.0.0.1";
public static void main(String[] args) throws IOException {
NioSocketConnector connector = new NioSocketConnector();
connector.setHandler(new MyClientHandler());
connector.getFilterChain().addLast("codec", new ProtocolCodecFilter(new TextLineCodecFactory()));
ConnectFuture future = connector.connect(new InetSocketAddress("127.0.0.1", 9898));
future.awaitUninterruptibly();//等待连接
IoSession session = future.getSession();
BufferedReader inputReader = new BufferedReader(new InputStreamReader(System.in));
String inputContent;
while (!(inputContent = inputReader.readLine()).equals("bye")) {
session.write(inputContent);
}
}
}
MyClientHandler:
package socketClient.mina;
import org.apache.mina.core.service.IoHandler;
import org.apache.mina.core.session.IdleStatus;
import org.apache.mina.core.session.IoSession;
public class MyClientHandler implements IoHandler {
public void exceptionCaught(IoSession arg0, Throwable arg1)
throws Exception {
System.out.println(arg1.getCause());
}
public void inputClosed(IoSession arg0) throws Exception {
// System.out.println("inputClosed");
}
public void messageReceived(IoSession arg0, Object arg1) throws Exception {
String msg = (String) arg1;
System.out.println("client messageReceived: " + msg);
}
public void messageSent(IoSession arg0, Object arg1) throws Exception {
System.out.println("client messageSent->" + (String)arg1);
}
public void sessionClosed(IoSession arg0) throws Exception {
System.out.println("sessionClosed "+arg0.hashCode());
}
public void sessionCreated(IoSession arg0) throws Exception {
System.out.println("sessionCreated "+arg0.hashCode());
}
public void sessionIdle(IoSession arg0, IdleStatus arg1) throws Exception {
System.out.println("sessionIdle "+arg0.hashCode()+" , "+arg1);
}
public void sessionOpened(IoSession arg0) throws Exception {
System.out.println("sessionOpened "+arg0.hashCode());
}
}版本一使用框架写好的TextLineCodecFactory来解析字符串，在实际实用场合中，往往要自定义解析功能，因此版本二自己写一个字符串解析功能。
版本二：
服务器端：
Main: 主函数
MyDecoder: 实现数据的解码
MyEncoder: 实现数据的编码
MyHandler:
MyProtocolFactory: 生成编码和解码器
MyCumulativeEncoder: 实现数据的编码，可将服务器数据进行缓存，防止数据丢失
Main:
package com.socket.r1;
import java.io.IOException;
import java.net.InetSocketAddress;
import org.apache.mina.core.session.IdleStatus;
import org.apache.mina.filter.codec.ProtocolCodecFilter;
import org.apache.mina.filter.codec.textline.TextLineCodecFactory;
import org.apache.mina.filter.logging.LoggingFilter;
import org.apache.mina.transport.socket.nio.NioSocketAcceptor;
public class Main {
public static int port = 9898;
public static void main(String[] args) {
NioSocketAcceptor acceptor = new NioSocketAcceptor();
try {
acceptor.setHandler(new MyHandler());
acceptor.getFilterChain().addLast("logger", new LoggingFilter());
acceptor.getFilterChain().addLast("codec", new ProtocolCodecFilter(new MyProtocolCodecFactory()));
acceptor.getSessionConfig().setIdleTime(IdleStatus.BOTH_IDLE, 125);
acceptor.bind(new InetSocketAddress(port));
} catch (IOException e) {
e.printStackTrace();
}
}
}MyDecoder:
package com.socket.r1;
import org.apache.mina.core.buffer.IoBuffer;
import org.apache.mina.core.session.IoSession;
import org.apache.mina.filter.codec.ProtocolDecoder;
import org.apache.mina.filter.codec.ProtocolDecoderOutput;
public class MyDecoder implements ProtocolDecoder {
public void decode(IoSession session, IoBuffer in, ProtocolDecoderOutput output)
throws Exception {
//记录字符流的读取位置
int startPosition = in.position();
while(in.hasRemaining()){
byte b = in.get();
if(b == '\n'){
int curPosition = in.position();
//记录字符流的末位置
int limit = in.limit();
//将读取指针设置为初始位置
in.position(startPosition);
//将结束位置设置为当前读取位置
in.limit(curPosition);
IoBuffer buf = in.slice();
byte[] bytes = new byte[buf.limit()];
//将截取的内容放进bytes数组
buf.get(bytes);
String str = new String(bytes);
output.write(str);
in.position(curPosition);
in.limit(limit);
}
}
}
public void dispose(IoSession arg0) throws Exception {
System.out.println("dispose" + arg0.hashCode());
}
public void finishDecode(IoSession arg0, ProtocolDecoderOutput arg1)
throws Exception {
System.out.println("finishDecode" + arg0.hashCode());
}
}MyEncoder:
package com.socket.r1;
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.ProtocolEncoder;
import org.apache.mina.filter.codec.ProtocolEncoderOutput;
public class MyEncoder implements ProtocolEncoder {
public void dispose(IoSession arg0) throws Exception {
System.out.println("dispose" + arg0.hashCode());
}
public void encode(IoSession arg0, Object msg, ProtocolEncoderOutput output)
throws Exception {
String s= null;
if(msg instanceof String){
s = (String) msg;
}
if(s!=null){
CharsetEncoder charsetEncoder = (CharsetEncoder) arg0.getAttribute("encoder");
if(charsetEncoder ==null){
charsetEncoder = Charset.defaultCharset().newEncoder();
arg0.setAttribute("encoder",charsetEncoder);
}
IoBuffer ioBuffer = IoBuffer.allocate(s.length());
ioBuffer.setAutoExpand(true);
ioBuffer.putString(s, charsetEncoder);
ioBuffer.flip();
output.write(ioBuffer);
}
}
}MyHandler跟版本一的一样，这里就不贴代码了。
MyCumulativeDecoder ：
package com.socket.r1;
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;
public class MyCumulativeDecoder extends CumulativeProtocolDecoder {
/**
* 确认读取完成时return true
*/
@Override
protected boolean doDecode(IoSession session, IoBuffer in, ProtocolDecoderOutput output)
throws Exception {
int startPosition = in.position();
while(in.hasRemaining()){
byte b = in.get();
if(b == '\n'){
int curPosition = in.position();
int limit = in.limit();
in.position(startPosition);
in.limit(curPosition);
IoBuffer buf = in.slice();
byte[] bytes = new byte[buf.limit()];
buf.get(bytes);
String str = new String(bytes);
output.write(str);
in.position(curPosition);
in.limit(limit);
return true;
}
}
//取消此次的读取，将读取位置重置
in.position(startPosition);
return false;
}
}MyProtocolCodecFactory ：
package com.socket.r1;
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;
public class MyProtocolCodecFactory implements ProtocolCodecFactory {
// private MyDecoder decoder;
private MyCumulativeDecoder decoder;
private MyEncoder encoder;
public MyProtocolCodecFactory() {
// decoder = new MyDecoder();
decoder = new MyCumulativeDecoder();
encoder = new MyEncoder();
}
public ProtocolDecoder getDecoder(IoSession arg0) throws Exception {
return decoder;
}
public ProtocolEncoder getEncoder(IoSession arg0) throws Exception {
return encoder;
}
}