Netty入门学习系列--helloworld服务端

Posted 2021-04-30 精讲JAVA

netty服务端

结合上面几篇文章，我们大体了解了netty使用的nio的原理，但是编写一个通信，使用nio过于复杂，对于我们来说，快捷使用nio通信变得尤为重要，于是，我们的主角netty出现了，简化原生nio开发。

public class NettyServerTest {

public static void main(String [] args){
    new NettyServerTest().bing();
}
private void bing(){
    EventLoopGroup bossgroup = new NioEventLoopGroup();
    EventLoopGroup workgroup = new NioEventLoopGroup();
    ServerBootstrap serverBootstrap = new ServerBootstrap();
    serverBootstrap.group(bossgroup,workgroup)
            .channel(NioserverSocketChannel.class)
            .option(ChannelOption.SO_BACKLOG,1024).childHandler(new NettyChildHandle());
    try {
        ChannelFuture cf = serverBootstrap.bind(9999).sync();
        cf.channel().closeFuture().sync();
    } catch (InterruptedException ignored) {
    } finally {
        bossgroup.shutdownGracefully();
        workgroup.shutdownGracefully();
    }
}
private class NettyChildHandle extends ChannelInitializer<socketchannel> {
    @Override
    protected void initChannel(SocketChannel ch) throws Exception {
        ch.pipeline().addLast(new NettyServerHandle());
    }
}}

NettyServerHandle用来处理通信请求,最主要的是实现里面的channelRead、channelReadComplete、exceptionCaught三个方法

public class NettyServerHandle extends ChannelInboundHandlerAdapter {

@Override
public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
    ByteBuf byteBuf = (ByteBuf) msg;
    byte [] bytes = new byte[byteBuf.readableBytes()];
    byteBuf.readBytes(bytes);
    String body = new String(bytes,"UTF-8");
    System.out.println("收到来自外星的命令"+body);
    String currentTime = "hello".equals(body)?"my name is netty":"No";
    ByteBuf resp = Unpooled.copiedBuffer(currentTime.getBytes());
    ctx.write(resp);
}
@Override
public void channelReadComplete(ChannelHandlerContext ctx) throws Exception {
     ctx.flush();
}
@Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
    ctx.close();
}}

截止目前，netty的服务端编写完成。，下一篇编写客户端，客户端相对来说较为简单