netty基础--基本收发
使用maven构建一个基本的netty收发应用，作为其他应用的基础。客户端使用packet sender工具。
1 添加netty依赖
<dependency>
<groupId>io.netty</groupId>
<artifactId>netty-all</artifactId>
<version>4.0.0.Final</version>
</dependency>
package io.netty.example.basic;
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;/**
* main class
* @author Sylar
* @Time 2017-01-02
*/
public class NettyBaisc {private int port;
public NettyBaisc(int port) {
this.port = port;
}public void run() throws Exception {
EventLoopGroup bossGroup = new NioEventLoopGroup(); // (1)
EventLoopGroup workerGroup = new NioEventLoopGroup();
try {
/*创建一个新的 ServerBootstrap 来创建和绑定新的 Channel
指定 EventLoopGroups 从 ServerChannel 和接收到的管道来注册并获取 EventLoops
指定 Channel 类来使用
设置处理器用于处理接收到的管道的 I/O 和数据
通过配置的引导来绑定管道
ChannelInitializer 负责设置 ChannelPipeline
实现 initChannel() 来添加需要的处理器到 ChannelPipeline。一旦完成了这方法 ChannelInitializer 将会从 ChannelPipeline 删除自身。*/
ServerBootstrap b = new ServerBootstrap(); // (2)
b.group(bossGroup, workerGroup)
.channel(NioServerSocketChannel.class) // (3)
.childHandler(new ChannelInitializer<SocketChannel>() { // (4)
@Override
public void initChannel(SocketChannel ch) throws Exception {
ch.pipeline().addLast(new NettyBaiscHandler());
}
})
.option(ChannelOption.SO_BACKLOG, 128) // (5)
.childOption(ChannelOption.SO_KEEPALIVE, true); // (6)// Bind and start to accept incoming connections.
ChannelFuture f = b.bind(port).sync(); // (7)// Wait until the server socket is closed.
// In this example, this does not happen, but you can do that to gracefully
// shut down your server.
f.channel().closeFuture().sync();
} finally {
workerGroup.shutdownGracefully();
bossGroup.shutdownGracefully();
}
}public static void main(String[] args) throws Exception {
int port;
if (args.length > 0) {
port = Integer.parseInt(args[0]);
} else {
port = 8080;
}
new NettyBaisc(port).run();
}
}
package io.netty.example.basic;
import java.io.UnsupportedEncodingException;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;
import io.netty.util.CharsetUtil;
import io.netty.util.ReferenceCountUtil;
/**
* handler class
* @author Sylar
* @Time 2017-01-02
*/
public class NettyBaiscHandler extends ChannelInboundHandlerAdapter { // (1)
@Override
public void channelActive(ChannelHandlerContext ctx) throws Exception {
System.out.println(">>>>>>>>connect in>>>>>>>>");
}
@Override
public void channelInactive(ChannelHandlerContext ctx) throws Exception {
System.out.println(">>>>>>>>connect out>>>>>>>>");
}
@Override
public void channelRead(ChannelHandlerContext ctx, Object msg) {
ByteBuf buf = (ByteBuf) msg;
/*byte[] req = new byte[buf.readableBytes()];
buf.readBytes(req);
String body = new String(req);
System.out.println("Server received: " + body);*/
System.out.println("Client received: " + buf.toString(CharsetUtil.UTF_8));
ctx.writeAndFlush(Unpooled.copiedBuffer("Ack", CharsetUtil.UTF_8));
/*ctx.write(Unpooled.copiedBuffer("Ack", CharsetUtil.UTF_8));
ctx.flush();*/
}
/* public void channelRead(ChannelHandlerContext ctx, Object msg) { // (2)
// Discard the received data silently.
//((ByteBuf) msg).release(); // (3)
ByteBuf in = (ByteBuf) msg;
try {
while (in.isReadable()) { // (1)
System.out.print((char) in.readByte());
System.out.flush();
}
} finally {
ReferenceCountUtil.release(msg); // (2)
}
}*/@Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) { // (4)
// Close the connection when an exception is raised.
cause.printStackTrace();
ctx.close();
}
}
