netty的实例是什么？

netty的实例是什么？

package netty.timeserver.server;

import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelOption;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioServerSocketChannel;

public class TimeServer {

public void bind(int port) throws Exception {
EventLoopGroup bossGroup = new NioEventLoopGroup();
EventLoopGroup workerGroup = new NioEventLoopGroup();
try {
// 配置服务器的NIO线程租
ServerBootstrap b = new ServerBootstrap();
b.group(bossGroup, workerGroup)
.channel(NioServerSocketChannel.class)
.option(ChannelOption.SO_BACKLOG, 1024)
.childHandler(new ChildChannelHandler());

// 绑定端口，同步等待成功
ChannelFuture f = b.bind(port).sync();
// 等待服务端监听端口关闭
f.channel().closeFuture().sync();
} finally {
// 优雅退出，释放线程池资源
bossGroup.shutdownGracefully();
workerGroup.shutdownGracefully();
}
}

private class ChildChannelHandler extends ChannelInitializer {
@Override
protected void initChannel(SocketChannel arg0) throws Exception {
System.out.println("server initChannel..");
arg0.pipeline().addLast(new TimeServerHandler());
}
}

public static void main(String[] args) throws Exception {
int port = 9000;
if (args != null && args.length > 0) {
try {
port = Integer.valueOf(args[0]);
} catch (NumberFormatException e) {

}
}

new TimeServer().bind(port);
}
}

TimeServerHandler.java

package netty.timeserver.server;

import java.util.Date;

import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;

public class TimeServerHandler extends ChannelInboundHandlerAdapter {

@Override
public void channelRead(ChannelHandlerContext ctx, Object msg)
throws Exception {
System.out.println("server channelRead..");
ByteBuf buf = (ByteBuf) msg;
byte[] req = new byte[buf.readableBytes()];
buf.readBytes(req);
String body = new String(req, "UTF-8");
System.out.println("The time server receive order:" + body);
String currentTime = "QUERY TIME ORDER".equalsIgnoreCase(body) ? new Date(
System.currentTimeMillis()).toString() : "BAD ORDER";
ByteBuf resp = Unpooled.copiedBuffer(currentTime.getBytes());
ctx.write(resp);
}

@Override
public void channelReadComplete(ChannelHandlerContext ctx) throws Exception {
System.out.println("server channelReadComplete..");
ctx.flush();//刷新后才将数据发出到SocketChannel
}

@Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause)
throws Exception {
System.out.println("server exceptionCaught..");
ctx.close();
}

}

TimeClient.java

package netty.timeserver.client;

import io.netty.bootstrap.Bootstrap;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelOption;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioSocketChannel;

public class TimeClient {

public void connect(int port, String host) throws Exception {
// 配置客户端NIO线程组
EventLoopGroup group = new NioEventLoopGroup();
try {
Bootstrap b = new Bootstrap();
b.group(group).channel(NioSocketChannel.class)
.option(ChannelOption.TCP_NODELAY, true)
.handler(new ChannelInitializer() {
@Override
protected void initChannel(SocketChannel arg0)
throws Exception {
System.out.println("client initChannel..");
arg0.pipeline().addLast(new TimeClientHandler());
}
});
// 发起异步连接操作
ChannelFuture f = b.connect(host, port).sync();
// 等待客户端链路关闭
f.channel().closeFuture().sync();
} finally {
// 优雅退出，释放NIO线程组
group.shutdownGracefully();
}
}

public static void main(String[] args) throws Exception {
int port = 9000;
if (args != null && args.length > 0) {
try {
port = Integer.parseInt(args[0]);
} catch (Exception e) {
}
}
new TimeClient().connect(port, "127.0.0.1");
}
}

TimeClientHandler.java

package netty.timeserver.client;

import java.util.logging.Logger;

import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;

public class TimeClientHandler extends ChannelInboundHandlerAdapter {

private static final Logger logger = Logger
.getLogger(TimeClientHandler.class.getName());

private final ByteBuf firstMessage;

public TimeClientHandler() {
byte[] req = "QUERY TIME ORDER".getBytes();
firstMessage = Unpooled.buffer(req.length);
firstMessage.writeBytes(req);
}

@Override
public void channelActive(ChannelHandlerContext ctx) throws Exception {
//与服务端建立连接后
System.out.println("client channelActive..");
ctx.writeAndFlush(firstMessage);
}

@Override
public void channelRead(ChannelHandlerContext ctx, Object msg)
throws Exception {
System.out.println("client channelRead..");
//服务端返回消息后
ByteBuf buf = (ByteBuf) msg;
byte[] req = new byte[buf.readableBytes()];
buf.readBytes(req);
String body = new String(req, "UTF-8");
System.out.println("Now is :" + body);
}

@Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause)
throws Exception {
System.out.println("client exceptionCaught..");
// 释放资源
logger.warning("Unexpected exception from downstream:"
+ cause.getMessage());
ctx.close();
}
使用maven，在pom.xml中添加如下代码

io.netty
netty-all
5.0.0.Alpha2


第二步： 编写Server端代码
NettyServerBootstrap代码
import java.util.concurrent.TimeUnit;

import org.apache.log4j.Logger;

import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelOption;
import io.netty.channel.ChannelPipeline;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioServerSocketChannel;
import io.netty.handler.codec.LengthFieldBasedFrameDecoder;
import io.netty.handler.timeout.IdleStateHandler;

d(port).sync();
if (f.isSuccess()) {
logger.debug("启动Netty服务成功，端口号：" + this.port);
}
// 关闭连接
f.channel().closeFuture().sync();

} catch (Exception e) {
logger.error("启动Netty服务异常，异常信息：" + e.getMessage());
e.printStackTrace();
} finally {
boss.shutdownGracefully();
worker.shutdownGracefully();
}
}

public static void main(String[] args) throws InterruptedException {

NettyServerBootstrap server= new NettyServerBootstrap(9999);

}

}

NettyServerHandler代码
import java.io.UnsupportedEncodingException;

import com.datong.base.module.netty.common.Constant;

import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelHandlerAdapter;
import io.netty.channel.ChannelHandlerContext;

public class NettyServerHandler extends ChannelHandlerAdapter {

@Override
public void channelRead(ChannelHandlerContext ctx, Object msg) {

ByteBuf buf = (ByteBuf) msg;

String recieved = getMessage(buf);
System.out.println("服务器接收到消息：" + recieved);

try {
ctx.writeAndFlush(getSendByteBuf("APPLE"));
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
}


private String getMessage(ByteBuf buf) {

byte[] con = new byte[buf.readableBytes()];
buf.readBytes(con);
try {
return new String(con, Constant.UTF8);
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
return null;
}
}

private ByteBuf getSendByteBuf(String message)
throws UnsupportedEncodingException {

byte[] req = message.getBytes("UTF-8");
ByteBuf pingMessage = Unpooled.buffer();
pingMessage.writeBytes(req);

return pingMessage;
}
}