netty 网络通信示例二： http://donald-draper.iteye.com/blog/2383328
netty 网络通信示例三： http://donald-draper.iteye.com/blog/2383392
上一篇我们在通过一个实例，来看一个用到编码器与解码器的示例，示例作用为服务器提供客户端计算请求，并将结果返回给客户端。之前实例的编解码器都是我们自己实现的，今天来看一个Netty基于textline编解码器通信示例：
服务端：
package netty.main.telnet;
import java.net.InetSocketAddress;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.ChannelFuture;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.nio.NioServerSocketChannel;
import io.netty.handler.logging.LogLevel;
import io.netty.handler.logging.LoggingHandler;
import io.netty.handler.ssl.SslContext;
import io.netty.handler.ssl.SslContextBuilder;
import io.netty.handler.ssl.util.SelfSignedCertificate;
import netty.initializer.telnet.TelnetServerInitializer;
/**
* textline通信server
* @author donald
* 2017年6月30日
* 上午11:07:08
*/
public final class TelnetServer {
private static final Logger log = LoggerFactory.getLogger(TelnetServer.class);
private static final boolean SSL = System.getProperty("ssl") != null;
private static final String ip = "192.168.31.153";
private static final int port = Integer.parseInt(System.getProperty("port", SSL? "10010" : "10020"));
public static void main(String[] args) throws Exception {
// Configure SSL.
final SslContext sslCtx;
if (SSL) {
SelfSignedCertificate ssc = new SelfSignedCertificate();
sslCtx = SslContextBuilder.forServer(ssc.certificate(), ssc.privateKey()).build();
} else {
sslCtx = null;
}
EventLoopGroup bossGroup = new NioEventLoopGroup(1);
EventLoopGroup workerGroup = new NioEventLoopGroup();
try {
ServerBootstrap serverBoot = new ServerBootstrap();
serverBoot.group(bossGroup, workerGroup)
.channel(NioServerSocketChannel.class)
.handler(new LoggingHandler(LogLevel.INFO))
.childHandler(new TelnetServerInitializer(sslCtx));
InetSocketAddress inetSocketAddress = new InetSocketAddress(ip,port);
ChannelFuture f = serverBoot.bind(inetSocketAddress).sync();
log.info("=========Server is start=========");
f.channel().closeFuture().sync();
} finally {
bossGroup.shutdownGracefully();
workerGroup.shutdownGracefully();
}
}
}
服务端处理器Initializer：
package netty.initializer.telnet;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelPipeline;
import io.netty.channel.socket.SocketChannel;
import io.netty.handler.codec.DelimiterBasedFrameDecoder;
import io.netty.handler.codec.Delimiters;
import io.netty.handler.codec.string.StringDecoder;
import io.netty.handler.codec.string.StringEncoder;
import io.netty.handler.ssl.SslContext;
import netty.handler.telnet.TelnetServerHandler;
/**
* Creates a newly configured {@link ChannelPipeline} for a new channel.
*/
public class TelnetServerInitializer extends ChannelInitializer<SocketChannel> {
private static final StringDecoder DECODER = new StringDecoder();
private static final StringEncoder ENCODER = new StringEncoder();
private static final TelnetServerHandler SERVER_HANDLER = new TelnetServerHandler();
private final SslContext sslCtx;
public TelnetServerInitializer(SslContext sslCtx) {
this.sslCtx = sslCtx;
}
@Override
public void initChannel(SocketChannel ch) throws Exception {
ChannelPipeline pipeline = ch.pipeline();
if (sslCtx != null) {
pipeline.addLast(sslCtx.newHandler(ch.alloc()));
}
// Add the text line codec combination first,
pipeline.addLast(new DelimiterBasedFrameDecoder(8192, Delimiters.lineDelimiter()));
// the encoder and decoder are static as these are sharable
pipeline.addLast(DECODER);
pipeline.addLast(ENCODER);
// and then business logic.
pipeline.addLast(SERVER_HANDLER);
}
}
服务端handler：
package netty.handler.telnet;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelFutureListener;
import io.netty.channel.ChannelHandler.Sharable;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.SimpleChannelInboundHandler;
import java.net.InetAddress;
import java.util.Date;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
*
* @author donald
* 2017年6月30日
* 上午11:02:29
* Sharable表示此对象在channel间共享
*/
@Sharable
public class TelnetServerHandler extends SimpleChannelInboundHandler<String> {
private static final Logger log = LoggerFactory.getLogger(TelnetServerHandler.class);
@Override
public void channelActive(ChannelHandlerContext ctx) throws Exception {
// Send greeting for a new connection.
ctx.write("Welcome to " + InetAddress.getLocalHost().getHostName() + "!\r\n");
ctx.write("It is " + new Date() + " now.\r\n");
ctx.flush();
}
@Override
public void channelRead0(ChannelHandlerContext ctx, String request) throws Exception {
// Generate and write a response.
String response;
boolean close = false;
log.info("========recieve message from client:"+request);
if (request.isEmpty()) {
response = "Please type something.\r\n";
} else if ("bye".equals(request.toLowerCase())) {
response = "Have a good day!\r\n";
close = true;
} else {
response = "Did you say '" + request + "'?\r\n";
}
// We do not need to write a ChannelBuffer here.
// We know the encoder inserted at TelnetPipelineFactory will do the conversion.
ChannelFuture future = ctx.write(response);
// Close the connection after sending 'Have a good day!'
// if the client has sent 'bye'.
if (close) {
future.addListener(ChannelFutureListener.CLOSE);
}
}
@Override
public void channelReadComplete(ChannelHandlerContext ctx) {
ctx.flush();
}
@Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
cause.printStackTrace();
ctx.close();
}
}
客户端：
package netty.main.telnet;
import io.netty.bootstrap.Bootstrap;
import io.netty.channel.Channel;
import io.netty.channel.ChannelFuture;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.nio.NioSocketChannel;
import io.netty.handler.ssl.SslContext;
import io.netty.handler.ssl.SslContextBuilder;
import io.netty.handler.ssl.util.InsecureTrustManagerFactory;
import netty.initializer.telnet.TelnetClientInitializer;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.InetSocketAddress;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* textline通信Client
* @author donald
* 2017年6月30日
* 上午11:26:30
*/
public final class TelnetClient {
private static final Logger log = LoggerFactory.getLogger(TelnetServer.class);
static final boolean SSL = System.getProperty("ssl") != null;
public static final String ip = System.getProperty("host", "192.168.31.153");
public static final int port = Integer.parseInt(System.getProperty("port", SSL? "10010" : "10020"));
public static void main(String[] args) throws Exception {
// Configure SSL.
final SslContext sslCtx;
if (SSL) {
sslCtx = SslContextBuilder.forClient()
.trustManager(InsecureTrustManagerFactory.INSTANCE).build();
} else {
sslCtx = null;
}
EventLoopGroup group = new NioEventLoopGroup();
try {
Bootstrap b = new Bootstrap();
b.group(group)
.channel(NioSocketChannel.class)
.handler(new TelnetClientInitializer(sslCtx));
InetSocketAddress inetSocketAddress = new InetSocketAddress(ip,port);
// Start the connection attempt.
Channel ch = b.connect(inetSocketAddress).sync().channel();
log.info("=========Client is start=========");
// Read commands from the stdin.
ChannelFuture lastWriteFuture = null;
BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
for (;;) {
String line = in.readLine();
if (line == null) {
break;
}
// Sends the received line to the server.
lastWriteFuture = ch.writeAndFlush(line + "\r\n");
// If user typed the 'bye' command, wait until the server closes
// the connection.
if ("bye".equals(line.toLowerCase())) {
ch.closeFuture().sync();
break;
}
}
// Wait until all messages are flushed before closing the channel.
if (lastWriteFuture != null) {
lastWriteFuture.sync();
}
} finally {
group.shutdownGracefully();
}
}
}
客户端处理器Initializer：
package netty.initializer.telnet;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelPipeline;
import io.netty.channel.socket.SocketChannel;
import io.netty.handler.codec.DelimiterBasedFrameDecoder;
import io.netty.handler.codec.Delimiters;
import io.netty.handler.codec.string.StringDecoder;
import io.netty.handler.codec.string.StringEncoder;
import io.netty.handler.ssl.SslContext;
import netty.handler.telnet.TelnetClientHandler;
import netty.main.telnet.TelnetClient;
/**
* Creates a newly configured {@link ChannelPipeline} for a new channel.
*/
public class TelnetClientInitializer extends ChannelInitializer<SocketChannel> {
private static final StringDecoder DECODER = new StringDecoder();
private static final StringEncoder ENCODER = new StringEncoder();
private static final TelnetClientHandler CLIENT_HANDLER = new TelnetClientHandler();
private final SslContext sslCtx;
public TelnetClientInitializer(SslContext sslCtx) {
this.sslCtx = sslCtx;
}
@Override
public void initChannel(SocketChannel ch) {
ChannelPipeline pipeline = ch.pipeline();
if (sslCtx != null) {
pipeline.addLast(sslCtx.newHandler(ch.alloc(), TelnetClient.ip, TelnetClient.port));
}
// Add the text line codec combination first,
pipeline.addLast(new DelimiterBasedFrameDecoder(8192, Delimiters.lineDelimiter()));
pipeline.addLast(DECODER);
pipeline.addLast(ENCODER);
// and then business logic.
pipeline.addLast(CLIENT_HANDLER);
}
}
客户端处理器：
package netty.handler.telnet;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import io.netty.channel.ChannelHandler.Sharable;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.SimpleChannelInboundHandler;
/**
*
* @author donald
* 2017年6月30日
* 上午10:59:47
* Sharable表示此对象在channel间共享
*/
@Sharable
public class TelnetClientHandler extends SimpleChannelInboundHandler<String> {
private static final Logger log = LoggerFactory.getLogger(TelnetClientHandler.class);
@Override
protected void channelRead0(ChannelHandlerContext ctx, String msg) throws Exception {
log.info("====recieve message from server:"+msg);
}
@Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
cause.printStackTrace();
ctx.close();
}
}
启动服务端与客户端，在客户端控制台输入hello server，换行输入bye,
服务端：
[INFO ] 2017-07-06 12:56:52 io.netty.handler.logging.LoggingHandler [id: 0x1ee25138] REGISTERED
[INFO ] 2017-07-06 12:56:52 io.netty.handler.logging.LoggingHandler [id: 0x1ee25138] BIND: /192.168.31.153:10020
[INFO ] 2017-07-06 12:56:52 netty.main.telnet.TelnetServer =========Server is start=========
[INFO ] 2017-07-06 12:56:52 io.netty.handler.logging.LoggingHandler [id: 0x1ee25138, L:/192.168.31.153:10020] ACTIVE
[INFO ] 2017-07-06 12:56:58 io.netty.handler.logging.LoggingHandler [id: 0x1ee25138, L:/192.168.31.153:10020] READ: [id: 0x4c1ab5f9, L:/192.168.31.153:10020 - R:/192.168.31.153:13357]
[INFO ] 2017-07-06 12:56:58 io.netty.handler.logging.LoggingHandler [id: 0x1ee25138, L:/192.168.31.153:10020] READ COMPLETE
[INFO ] 2017-07-06 12:57:13 netty.handler.telnet.TelnetServerHandler ========recieve message from client:hello server
[INFO ] 2017-07-06 12:57:19 netty.handler.telnet.TelnetServerHandler ========recieve message from client:yes
[INFO ] 2017-07-06 12:57:22 netty.handler.telnet.TelnetServerHandler ========recieve message from client:bye
客户端：
[INFO ] 2017-07-06 12:56:58 netty.main.telnet.TelnetServer =========Client is start=========
[INFO ] 2017-07-06 12:56:59 netty.handler.telnet.TelnetClientHandler ====recieve message from server:Welcome to donaldHP!
[INFO ] 2017-07-06 12:56:59 netty.handler.telnet.TelnetClientHandler ====recieve message from server:It is Thu Jul 06 12:56:59 CST 2017 now.
hello server
[INFO ] 2017-07-06 12:57:13 netty.handler.telnet.TelnetClientHandler ====recieve message from server:Did you say 'hello server'?
yes
[INFO ] 2017-07-06 12:57:19 netty.handler.telnet.TelnetClientHandler ====recieve message from server:Did you say 'yes'?
bye
[INFO ] 2017-07-06 12:57:22 netty.handler.telnet.TelnetClientHandler ====recieve message from server:Have a good day!