首先值得注意的是netty的jar包版本问题，版本不同，运用的方式也不同。我这里用4.0版本。
对于小白来说，netty到底是什么，我就没必要在这里阐明了，因为百度上比我描述的更全面。
这里就直接开门见山，代码走起。。。
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;
/**
* 服务器
*/
public class NettyServer {
private final int port = 8989;
public static void main(String[] args) {
new NettyServer().nettyServer();
}
public void nettyServer(){
EventLoopGroup bossGroup = new NioEventLoopGroup();
EventLoopGroup workerGroup = new NioEventLoopGroup();
try {
ServerBootstrap serverBootStrap = new ServerBootstrap();
serverBootStrap.group(bossGroup,workerGroup).channel(NioServerSocketChannel.class)
.option(ChannelOption.SO_BACKLOG, 1024)
.childHandler(new ChildChannelHandler());
ChannelFuture futrue = serverBootStrap.bind(port).sync();
futrue.channel().closeFuture().sync();
} catch (Exception e) {
// TODO: handle exception
}
}
private class ChildChannelHandler extends ChannelInitializer<SocketChannel>{
@Override
protected void initChannel(SocketChannel ch) throws Exception {
ch.pipeline().addLast(new SimpleServerHandler());
}
}
}
import java.util.Scanner;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;
public class SimpleServerHandler extends ChannelInboundHandlerAdapter {
@Override
public void channelActive(ChannelHandlerContext ctx) throws Exception {
ChannelManager.serverChannel = ctx;
new Thread(new Runnable() {
@Override
public void run() {
// TODO Auto-generated method stub
while(true){
Scanner sc = new Scanner(System.in);
byte [] req = sc.nextLine().getBytes();
ByteBuf msg = Unpooled.buffer(req.length);
msg.writeBytes(req);
ChannelManager.serverChannel.writeAndFlush(msg);
}
}
}).start();
}
@Override
public void channelRead(ChannelHandlerContext ctx, Object msg)
throws Exception {
ByteBuf buf = (ByteBuf) msg;
byte [] req = new byte[buf.readableBytes()];
buf.readBytes(req);
String message = new String(req,"UTF-8");
System.out.println("server:"+message);
}
}
上述两个类实现netty的服务端，下面就是客户端啦
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 NettyClient {
public static void main(String[] args) {
new NettyClient().connect(8989, "127.0.0.1");
}
public void connect(int port, String host){
EventLoopGroup group = new NioEventLoopGroup();
try {
Bootstrap bootstrap = new Bootstrap();
bootstrap.group(group)
.channel(NioSocketChannel.class)
.option(ChannelOption.TCP_NODELAY, true)
.handler(new ChannelInitializer<SocketChannel>() {
@Override
protected void initChannel(SocketChannel ch) throws Exception {
// TODO Auto-generated method stub
ch.pipeline().addLast(new SimpleClientHandler());
}
});
ChannelFuture channelFuture = bootstrap.connect(host,port).sync();
channelFuture.channel().closeFuture().sync();
} catch (Exception e) {
// TODO: handle exception
}
}
}
import java.util.Scanner;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;
public class SimpleClientHandler extends ChannelInboundHandlerAdapter {
private ByteBuf clientMessage;
public SimpleClientHandler(){
byte [] req = "call-user-service".getBytes();
clientMessage = Unpooled.buffer(req.length);
clientMessage.writeBytes(req);
}
@Override
public void channelActive(ChannelHandlerContext ctx) throws Exception {
ChannelManager.clientChannel = ctx;
new Thread(new Runnable() {
@Override
public void run() {
// TODO Auto-generated method stub
while(true){
Scanner sc = new Scanner(System.in);
byte [] req = sc.nextLine().getBytes();
ByteBuf msg = Unpooled.buffer(req.length);
msg.writeBytes(req);
ChannelManager.clientChannel.writeAndFlush(msg);
}
}
}).start();
}
@Override
public void channelRead(ChannelHandlerContext ctx, Object msg)
throws Exception {
ByteBuf buf = (ByteBuf) msg;
byte [] req = new byte[buf.readableBytes()];
buf.readBytes(req);
String message = new String(req,"UTF-8");
System.out.println("client:"+message);
}
@Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause)
throws Exception {
ctx.close();
}
}
好了，万事俱备，再添加一个ChannelManager.java netty的通道管理器
import io.netty.channel.ChannelHandlerContext;
public class ChannelManager {
public static ChannelHandlerContext serverChannel;
public static ChannelHandlerContext clientChannel;
}
这样就可以实现netty的前后端的控制台通讯了，代码解释就不进行了