2019独角兽企业重金招聘Python工程师标准>>> 
主要思路：
* 服务器每隔两秒发送一次服务器的时间
* 客户端接收服务器端数据，打印出服务器的时间
服务器端代码
package netty.time.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;
import io.netty.handler.timeout.ReadTimeoutHandler;
import io.netty.handler.timeout.WriteTimeoutHandler;
/**
* Created with IntelliJ IDEA.
* User: ASUS
* Date: 14-5-7
* Time: 上午10:10
* To change this template use File | Settings | File Templates.
*/
public class TimeServer {
public static void main(String[] args) {
// EventLoop 代替原来的 ChannelFactory
EventLoopGroup bossGroup = new NioEventLoopGroup();
EventLoopGroup workerGroup = new NioEventLoopGroup();
try {
ServerBootstrap serverBootstrap = new ServerBootstrap();
serverBootstrap.group(bossGroup, workerGroup)
.channel(NioServerSocketChannel.class)
.childHandler(new ChannelInitializer() {
@Override
public void initChannel(SocketChannel ch) throws Exception {
ch.pipeline().addLast(
new TimeServerHandler(),
new WriteTimeoutHandler(10),
//控制写入超时10秒构造参数10表示如果持续10秒钟都没有数据写了，那么就超时。
new ReadTimeoutHandler(10)
);
}
}).option(ChannelOption.SO_KEEPALIVE, true);
ChannelFuture f = serverBootstrap.bind(9090).sync();
f.channel().closeFuture().sync();
} catch (InterruptedException e) {
} finally {
workerGroup.shutdownGracefully();
bossGroup.shutdownGracefully();
}
}
} package netty.time.server;
import io.netty.buffer.ByteBuf;
import io.netty.channel.*;
public class TimeServerHandler extends ChannelInboundHandlerAdapter {
//ChannelHandlerContext通道处理上下文
@Override
public void channelActive(final ChannelHandlerContext ctx) throws InterruptedException { // (1)
while (true) {
ByteBuf time = ctx.alloc().buffer(4); //为ByteBuf分配四个字节
time.writeInt((int) (System.currentTimeMillis() / 1000L + 2208988800L));
ctx.writeAndFlush(time); // (3)
Thread.sleep(2000);
}
}
@Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
cause.printStackTrace();
ctx.close();
}
}客户端代码
package netty.time.server;
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;
/**
* 服务器每隔两秒发送一次服务器的时间
* 客户端接收服务器端数据，打印出服务器的时间
*/
public class TimeClient {
public static void main(String[] args) throws Exception {
EventLoopGroup workerGroup = new NioEventLoopGroup();
try {
Bootstrap b = new Bootstrap(); // (1)
b.group(workerGroup); // (2)
b.channel(NioSocketChannel.class); // (3)
b.option(ChannelOption.SO_KEEPALIVE, true); // (4)
b.handler(new ChannelInitializer() {
@Override
public void initChannel(SocketChannel ch) throws Exception {
ch.pipeline().addLast(new TimeClientHandler());
}
});
// Start the client.
ChannelFuture f = b.connect("127.0.0.1", 9090).sync(); // (5)
// Wait until the connection is closed.
f.channel().closeFuture().sync();
} finally {
workerGroup.shutdownGracefully();
}
}
} package netty.time.server;
import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;
import java.util.Date;
public class TimeClientHandler extends ChannelInboundHandlerAdapter {
@Override
public void channelRead(ChannelHandlerContext ctx, Object msg) {
ByteBuf m = (ByteBuf) msg;
try {
long currentTimeMillis = (m.readUnsignedInt() - 2208988800L) * 1000L;
System.out.println(new Date(currentTimeMillis));
} finally {
m.release();
}
}
@Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
cause.printStackTrace();
ctx.close();
}
}运行结果：
Sun Jun 22 18:40:42 CST 2014
Sun Jun 22 18:40:44 CST 2014
Sun Jun 22 18:40:46 CST 2014
Sun Jun 22 18:40:48 CST 2014
Sun Jun 22 18:40:50 CST 2014
Sun Jun 22 18:40:52 CST 2014
Sun Jun 22 18:40:54 CST 2014
Sun Jun 22 18:40:56 CST 2014
.................................
========END========