每日一得--netty
一，jar包下载
二，netty入门实例
TimeServer.java
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(); } }
netty入门实例
TimeServer.java
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(); } }