netty的简单的应用例子

一、简单的聊天室程序

　　

public class ChatClient {

    public static void main(String[] args) throws InterruptedException, IOException {
        NioEventLoopGroup nioEventLoopGroup = new NioEventLoopGroup();
        try{
            Bootstrap bootstrap = new Bootstrap();
            bootstrap.group(nioEventLoopGroup).channel(NioSocketChannel.class)
                .handler(new ChannelInitializer<SocketChannel>() {

                    @Override
                    protected void initChannel(SocketChannel ch) throws Exception {
                        ch.pipeline()
//                        .addLast(new DelimiterBasedFrameDecoder(4096, Delimiters.lineDelimiter()))
                        .addLast(new LineBasedFrameDecoder(1024))
                        .addLast(new StringDecoder(CharsetUtil.UTF_8))
                        .addLast(new StringEncoder(CharsetUtil.UTF_8))
                        .addLast(new SimpleChannelInboundHandler<String>() {

                            @Override
                            protected void channelRead0(ChannelHandlerContext ctx, String msg) throws Exception {
                                System.out.println(msg);
                                
                            }
                        });
                    }
                });
            ChannelFuture future = bootstrap.connect("localhost", 8888).sync();
            BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
            Channel channel = future.channel();
            while(true){
                channel.writeAndFlush(br.readLine()+"
");
            }
            
        }finally{
            nioEventLoopGroup.shutdownGracefully().sync();
        }
    }

}

public class ChatServer {

    public static void main(String[] args) throws InterruptedException {
        
        NioEventLoopGroup bossGroup = new NioEventLoopGroup();
        NioEventLoopGroup workerGroup = new NioEventLoopGroup();
        try{
            ServerBootstrap serverBootstrap = new ServerBootstrap();
            serverBootstrap.group(bossGroup, workerGroup).channel(NioServerSocketChannel.class)
                .childHandler(new ChannelInitializer<Channel>() {

                    @Override
                    protected void initChannel(Channel ch) throws Exception {
                        ch.pipeline()
//                        .addLast(new DelimiterBasedFrameDecoder(4096, Delimiters.lineDelimiter()))
                        .addLast(new LineBasedFrameDecoder(1024))
                        .addLast(new StringDecoder(CharsetUtil.UTF_8))
                        .addLast(new StringEncoder(CharsetUtil.UTF_8))
                        .addLast(new ChatServerHandler());
                    }
                    
                });
            ChannelFuture future = serverBootstrap.bind(8888).sync();
            future.channel().closeFuture().sync();
        }finally{
            bossGroup.shutdownGracefully().sync();
            workerGroup.shutdownGracefully().sync();
        }
        
    }
    
    

}

public class ChatServerHandler extends SimpleChannelInboundHandler<String>{
    
    public static final ChannelGroup group = new DefaultChannelGroup(GlobalEventExecutor.INSTANCE);


    @Override
    protected void channelRead0(ChannelHandlerContext ctx, String msg) throws Exception {
        Channel channel = ctx.channel();
        group.forEach(ch ->{
            if(channel != ch){
                ch.writeAndFlush(channel.remoteAddress()+": "+ msg+"
");
            }else{
                ch.writeAndFlush("自己： "+msg+"
");
            }
        });
    }
    
    @Override
    public void handlerAdded(ChannelHandlerContext ctx) throws Exception {
        Channel channel = ctx.channel();
        group.writeAndFlush("服务器： "+channel.remoteAddress()+"加入");
        group.add(channel);
    }
    
    @Override
    public void handlerRemoved(ChannelHandlerContext ctx) throws Exception {
        Channel channel = ctx.channel();
        group.writeAndFlush("服务器 ： "+channel.remoteAddress() + "离开");
        
    }
    
    
    @Override
    public void channelActive(ChannelHandlerContext ctx) throws Exception {
        System.out.println(ctx.channel().remoteAddress()+" 上线");
    }
    
    @Override
    public void channelInactive(ChannelHandlerContext ctx) throws Exception {
        System.out.println(ctx.channel().remoteAddress()+" 下线");
    }
    
    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
        cause.printStackTrace();
        ctx.close();
    }
    
    

}

二、使用netty传递对象，使用jdk自带的序列化

public class SubReqClient {

    public static void main(String[] args) {
        start();
    }
    
    public static void start(){
        NioEventLoopGroup group = new NioEventLoopGroup();
        
        try{
            Bootstrap bootstrap = new Bootstrap();
            bootstrap.group(group).channel(NioSocketChannel.class)
            .handler(new ChannelInitializer<Channel>() {

                @Override
                protected void initChannel(Channel ch) throws Exception {
                    ch.pipeline()
                    .addLast("decoder", new ObjectDecoder(ClassResolvers.cacheDisabled(
                            this.getClass().getClassLoader()
                    )))
                    .addLast("encoder", new ObjectEncoder())
                    .addLast(new SimpleChannelInboundHandler<Object>() {

                        @Override
                        protected void channelRead0(ChannelHandlerContext ctx, Object msg) throws Exception {
                            System.out.println(msg);
                        }
                        
                        @Override
                        public void channelActive(ChannelHandlerContext ctx) throws Exception {
                            User user = new User();
                            user.setName("runtu");
                            ctx.writeAndFlush(user);
                        }
                        
                    });
                }
            });
            ChannelFuture future = bootstrap.connect("localhost", 8888).sync();
            future.channel().closeFuture().sync();
            
        } catch (InterruptedException e) {
            e.printStackTrace();
        }finally{
            group.shutdownGracefully();
        }
    }

}

public class SubReqServer {

    public static void main(String[] args) {
        start();
    }
    
    public static void start(){
        NioEventLoopGroup bossGroup = new NioEventLoopGroup();
        NioEventLoopGroup workGroup = new NioEventLoopGroup();
        
        try{
            ServerBootstrap serverBootstrap = new ServerBootstrap();
            serverBootstrap.group(bossGroup,workGroup).channel(NioServerSocketChannel.class)
                .childHandler(new ChannelInitializer<Channel>() {

                    @Override
                    protected void initChannel(Channel ch) throws Exception {
                        ch.pipeline()
                        .addLast("decoder", new ObjectDecoder(ClassResolvers.cacheDisabled(
                                this.getClass().getClassLoader()
                        )))
                        .addLast("encoder", new ObjectEncoder())
                        .addLast(new SimpleChannelInboundHandler<Object>() {

                            @Override
                            protected void channelRead0(ChannelHandlerContext ctx, Object msg) throws Exception {
                                User user1 = (User)msg;
                                System.out.println(user1.getName());
                                
                                User user = new User();
                                user.setName("AQ");
                                ctx.writeAndFlush(user);
                                
                            }
                            
                        });
                    }
                });
            ChannelFuture future = serverBootstrap.bind(8888).sync();
            future.channel().closeFuture().sync();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }finally{
            bossGroup.shutdownGracefully();
            workGroup.shutdownGracefully();
        }
    }

}

public class User implements Serializable{

    private String name;
    private int  age;
    private String address;
    
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public int getAge() {
        return age;
    }
    public void setAge(int age) {
        this.age = age;
    }
    public String getAddress() {
        return address;
    }
    public void setAddress(String address) {
        this.address = address;
    }
    
    
    @Override
    public String toString() {
        return "User [name=" + name + ", age=" + age + ", address=" + address + "]";
    }
    
    
}

　　

三、使用messagepack进行序列化传递实体对象

　　由于java自带的序列化工具有着性能低、序列化后的码流大且不支持跨语言等各种缺陷，所以我们使用Msgpack库来进行序列化然后进行数据的传输。

　　我们需要额外引入两个jar包javassist-3.18.1-GA.jar 和msgpack-0.6.12.jar

public class NioClient {

    public static void main(String[] args) throws InterruptedException {
        
        NioEventLoopGroup group = new NioEventLoopGroup();
        
        try{
            Bootstrap bootStrap = new Bootstrap();
            bootStrap.group(group).channel(NioSocketChannel.class)
                .option(ChannelOption.TCP_NODELAY, true)
                .option(ChannelOption.CONNECT_TIMEOUT_MILLIS,3000)
                .handler(new ChannelInitializer<Channel>() {

                    @Override
                    protected void initChannel(Channel ch) throws Exception {
                        ch.pipeline()
                        .addLast("frameDecoder",new LengthFieldBasedFrameDecoder(1024, 0, 2,0,2))
                        .addLast(new MsgpackDecoder())
                        .addLast("frameEncoder",new LengthFieldPrepender(2))
                        .addLast(new MsgpackEncoder())
                        .addLast(new ClientHandler());
                    }
                });
            
            ChannelFuture future = bootStrap.connect("localhost", 9999).sync();
            future.channel().closeFuture().sync();
        }finally{
            group.shutdownGracefully();
        }
    }

}

public class ClientHandler extends SimpleChannelInboundHandler {

    @Override
    public void channelRead0(ChannelHandlerContext ctx, Object msg) throws Exception {
        System.out.println(msg);
    }

    @Override
    public void channelActive(ChannelHandlerContext ctx) throws Exception {
        //发送50个UserInfo给服务器，由于启用了粘包/拆包支持，所以这里连续发送多个也不会出现粘包的现象。
        for (int i = 0; i < 50; i++) {
            User user = new User();
            user.setName("张三"+i);
            ctx.write(user);
        }
        ctx.flush();
        System.out.println("-----------------send over-----------------");
    }

    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
        System.out.println("error");
    }
}

public class NioServer {
    
    public static void main(String[] args) throws InterruptedException {
        NioEventLoopGroup bossGroup = new NioEventLoopGroup();
        NioEventLoopGroup workGroup = new NioEventLoopGroup();
        
        try{
            ServerBootstrap serverBootstrap = new ServerBootstrap();
            serverBootstrap.group(bossGroup, workGroup).channel(NioServerSocketChannel.class)
                .childHandler(new ChannelInitializer<Channel>() {

                    @Override
                    protected void initChannel(Channel ch) throws Exception {
                        ch.pipeline()
                        .addLast("frameDecoder",new LengthFieldBasedFrameDecoder(1024, 0, 2,0,2))
                        .addLast(new MsgpackDecoder())
                        .addLast("frameEncoder",new LengthFieldPrepender(2))
                        .addLast(new MsgpackEncoder())
                        .addLast(new ServerHandler());
                    }
                });
            ChannelFuture future = serverBootstrap.bind(9999).sync();
            future.channel().closeFuture().sync();
        }finally{
            bossGroup.shutdownGracefully();
            workGroup.shutdownGracefully();
        }
    }

}

public class ServerHandler extends SimpleChannelInboundHandler {

    @Override
    public void channelRead0(ChannelHandlerContext ctx, Object msg) throws Exception {
        try {
        //直接输出msg
        System.out.println(msg.toString());
        User user = new User();
        user.setName("李四");
        //回复has receive 给客户端
            ctx.write(user);
        } catch (Exception e) {
            e.printStackTrace();
        }finally {
        }
    }

    @Override
    public void channelReadComplete(ChannelHandlerContext ctx) throws Exception {
        ctx.flush();
    }

}

public class MsgpackDecoder extends MessageToMessageDecoder<ByteBuf>{

    @Override
    protected void decode(ChannelHandlerContext ctx, ByteBuf buf, List<Object> out) throws Exception {
        
        final int length = buf.readableBytes();
        final byte[] array = new byte[length];
        buf.getBytes(buf.readerIndex(), array,0,length);
        MessagePack messagePack = new MessagePack();
        out.add(messagePack.read(array));
    }

}

public class MsgpackEncoder extends MessageToByteEncoder<Object>{

    @Override
    protected void encode(ChannelHandlerContext ctx, Object obj, ByteBuf out) throws Exception {
        MessagePack messagePack = new MessagePack();
        byte[] info = messagePack.write(obj);
        out.writeBytes(info);
    }

}

@Message
public class User {

    private String name;
    private int  age;
    private String address;
    
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public int getAge() {
        return age;
    }
    public void setAge(int age) {
        this.age = age;
    }
    public String getAddress() {
        return address;
    }
    public void setAddress(String address) {
        this.address = address;
    }
    
    
    @Override
    public String toString() {
        return "User [name=" + name + ", age=" + age + ", address=" + address + "]";
    }
    
    
}

四、使用Marshalling来对对象进行序列化，这种序列化方式需要对想实现Serializable接口

　　需要引入jar包 jboss-marshalling-2.0.6.Final.jar和jboss-marshalling-serial-2.0.6.Final.jar

public class SubReqClient {

    public static void main(String[] args) {
        start();
    }
    
    public static void start(){
        NioEventLoopGroup group = new NioEventLoopGroup();
        
        try{
            Bootstrap bootstrap = new Bootstrap();
            bootstrap.group(group).channel(NioSocketChannel.class)
            .handler(new ChannelInitializer<Channel>() {

                @Override
                protected void initChannel(Channel ch) throws Exception {
                    ch.pipeline().addLast(MarshallingCodeCFactory.buildMarshallingDecoder())
                    .addLast(MarshallingCodeCFactory.buildMarshallingEncoder())
                    .addLast(new SimpleChannelInboundHandler<Object>() {

                        @Override
                        protected void channelRead0(ChannelHandlerContext ctx, Object msg) throws Exception {
                            System.out.println(msg);
                        }
                        
                        @Override
                        public void channelActive(ChannelHandlerContext ctx) throws Exception {
                            User user = new User();
                            user.setName("runtu");
                            ctx.writeAndFlush(user);
                        }
                        
                    });
                }
            });
            ChannelFuture future = bootstrap.connect("localhost", 8888).sync();
            future.channel().closeFuture().sync();
            
        } catch (InterruptedException e) {
            e.printStackTrace();
        }finally{
            group.shutdownGracefully();
        }
    }

}

public class SubReqServer {

    public static void main(String[] args) {
        start();
    }
    
    public static void start(){
        NioEventLoopGroup bossGroup = new NioEventLoopGroup();
        NioEventLoopGroup workGroup = new NioEventLoopGroup();
        
        try{
            ServerBootstrap serverBootstrap = new ServerBootstrap();
            serverBootstrap.group(bossGroup,workGroup).channel(NioServerSocketChannel.class)
                .childHandler(new ChannelInitializer<Channel>() {

                    @Override
                    protected void initChannel(Channel ch) throws Exception {
                        ch.pipeline().addLast(MarshallingCodeCFactory.buildMarshallingDecoder())
                        .addLast(MarshallingCodeCFactory.buildMarshallingEncoder())
                        .addLast(new SimpleChannelInboundHandler<Object>() {

                            @Override
                            protected void channelRead0(ChannelHandlerContext ctx, Object msg) throws Exception {
                                User user1 = (User)msg;
                                System.out.println(user1.getName());
                                
                                User user = new User();
                                user.setName("AQ");
                                ctx.writeAndFlush(user);
                                
                            }
                            
                        });
                    }
                });
            ChannelFuture future = serverBootstrap.bind(8888).sync();
            future.channel().closeFuture().sync();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }finally{
            bossGroup.shutdownGracefully();
            workGroup.shutdownGracefully();
        }
    }

}

public class MarshallingCodeCFactory {
    
    public static MarshallingDecoder buildMarshallingDecoder(){
        final MarshallerFactory factory = Marshalling.getProvidedMarshallerFactory("serial");
        final MarshallingConfiguration configuration = new MarshallingConfiguration();
        configuration.setVersion(5);
        DefaultUnmarshallerProvider provider = new DefaultUnmarshallerProvider(factory, configuration);
        MarshallingDecoder decoder = new MarshallingDecoder(provider,1024);
        return decoder;
    }
    
    
    public static MarshallingEncoder buildMarshallingEncoder(){
        final MarshallerFactory factory = Marshalling.getProvidedMarshallerFactory("serial");
        final MarshallingConfiguration configuration = new MarshallingConfiguration();
        configuration.setVersion(5);
        MarshallerProvider provider = new DefaultMarshallerProvider(factory, configuration);
        MarshallingEncoder encoder = new MarshallingEncoder(provider);
        return encoder;
    }

}

public class User implements Serializable{

    private String name;
    private int  age;
    private String address;
    
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public int getAge() {
        return age;
    }
    public void setAge(int age) {
        this.age = age;
    }
    public String getAddress() {
        return address;
    }
    public void setAddress(String address) {
        this.address = address;
    }
    
    
    @Override
    public String toString() {
        return "User [name=" + name + ", age=" + age + ", address=" + address + "]";
    }
    
    
}

五、简单的http文件服务器

　　

public class HttpServer {

    public static void main(String[] args) {
        start();
    }
    
    public static void start(){
        NioEventLoopGroup bossGroup = new NioEventLoopGroup();
        NioEventLoopGroup workGroup = new NioEventLoopGroup();
        
        try{
            ServerBootstrap serverBootstrap = new ServerBootstrap();
            serverBootstrap.group(bossGroup,workGroup).channel(NioServerSocketChannel.class)
                .childHandler(new ChannelInitializer<Channel>() {

                    @Override
                    protected void initChannel(Channel ch) throws Exception {
                        ch.pipeline()
                        .addLast(new HttpRequestDecoder())
                        .addLast(new HttpObjectAggregator(65535))
                        .addLast(new HttpResponseEncoder())
                        .addLast(new ChunkedWriteHandler())
                        .addLast(new FileServerHandler1());
                    }
                });
            ChannelFuture future = serverBootstrap.bind(8888).sync();
            future.channel().closeFuture().sync();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }finally{
            bossGroup.shutdownGracefully();
            workGroup.shutdownGracefully();
        }
    }
}

public class FileServerHandler1 extends SimpleChannelInboundHandler<FullHttpRequest>{


        @Override
        protected void channelRead0(ChannelHandlerContext ctx, FullHttpRequest request) throws Exception {
            
            if(request.uri().equals("/favicon.ico")){
                return;
            }
            
            if(request.method() == HttpMethod.GET){
                String uri = request.uri();
                if(uri.startsWith("/file")){
                    
                    File file = new File("D:\12306Bypass\使用须知.txt");
                    RandomAccessFile randomAccessFile = null;
                    randomAccessFile = new RandomAccessFile(file, "r");
                    long fileLength = randomAccessFile.length();
                    HttpResponse response = new DefaultHttpResponse(HttpVersion.HTTP_1_1, HttpResponseStatus.OK);
                    response.headers().set(HttpHeaderNames.CONNECTION, HttpHeaderValues.KEEP_ALIVE)
                        .set("Content-Length", fileLength)
                        .set("Content-Type","text/html")
                        .set("Content-Disposition", "attachment;fileName="+"a.txt");        
                    
                    ctx.write(response);
                    ctx.write(new ChunkedFile(randomAccessFile, 0,fileLength,8192),ctx.newProgressivePromise());
                    ctx.writeAndFlush(LastHttpContent.EMPTY_LAST_CONTENT);
                        
            }else{
                FullHttpResponse response = new DefaultFullHttpResponse(HttpVersion.HTTP_1_1, HttpResponseStatus.OK);
                response.headers()
                .set("Content-Type", "text/plain;charset=utf-8")
                .set("Content_Length", response.content().readableBytes())
                .set("aaa", "cccc");
                response.content().writeBytes(Unpooled.copiedBuffer("服务器返回信息",CharsetUtil.UTF_8));
                ctx.writeAndFlush(response).addListener(ChannelFutureListener.CLOSE);
            }
        }
    }
        
        
    private static void setContentTypeHeader(HttpResponse response, File file){
        MimetypesFileTypeMap mimetypesFileTypeMap = new MimetypesFileTypeMap();
        response.headers().set(HttpHeaderNames.CONTENT_TYPE, mimetypesFileTypeMap.getContentType(file.getPath()));
    }
}

六、netty编写websocket服务器

public class WebSocketServer {

    public static void main(String[] args) throws InterruptedException {
        NioEventLoopGroup bossGroup = new NioEventLoopGroup();
        NioEventLoopGroup workerGroup = new NioEventLoopGroup();
        try{
            ServerBootstrap serverBootstrap = new ServerBootstrap();
            serverBootstrap.group(bossGroup,workerGroup).channel(NioServerSocketChannel.class)
                .childHandler(new ChannelInitializer<Channel>() {

                    @Override
                    protected void initChannel(Channel ch) throws Exception {
                        ch.pipeline()
                        .addLast(new HttpServerCodec())
                        .addLast(new HttpObjectAggregator(65536))
                        .addLast(new ChunkedWriteHandler())
                        .addLast(new WebSocketServerHandler());
                    }
                });
            ChannelFuture future = serverBootstrap.bind(8080).sync();
            future.channel().closeFuture().sync();
        }finally{
            bossGroup.shutdownGracefully().sync();
            workerGroup.shutdownGracefully().sync();
        }
    }

}

public class WebSocketServerHandler extends SimpleChannelInboundHandler<Object>{

    private WebSocketServerHandshaker handshaker;
    
    @Override
    protected void channelRead0(ChannelHandlerContext ctx, Object msg) throws Exception {
        if(msg instanceof FullHttpRequest){
            HandleHttpRequest(ctx,(FullHttpRequest)msg);
        }
        
        if(msg instanceof WebSocketFrame){
            handleWebSocket(ctx,(WebSocketFrame)msg);
        }
        
        
    }
    
    private void HandleHttpRequest(ChannelHandlerContext ctx,FullHttpRequest request){
        WebSocketServerHandshakerFactory factory = new WebSocketServerHandshakerFactory(
                "ws://localhost:8888/websocket",null,false);
        handshaker = factory.newHandshaker(request);
        if(handshaker == null){
            WebSocketServerHandshakerFactory.sendUnsupportedVersionResponse(ctx.channel());
        }else{
            handshaker.handshake(ctx.channel(),request);
        }
        
        
    }
    
    private void handleWebSocket(ChannelHandlerContext ctx,WebSocketFrame frame){
        
        if(frame instanceof CloseWebSocketFrame){
            handshaker.close(ctx.channel(), (CloseWebSocketFrame)frame.retain());
        }
        
        if(frame instanceof PingWebSocketFrame){
            ctx.channel().write(new PongWebSocketFrame(frame.content().retain()));
            return;
        }
        
        if(!(frame instanceof TextWebSocketFrame)){
            return;
        }
        
        String requestStr = ((TextWebSocketFrame) frame).text();
        System.out.println(requestStr);
        ctx.channel().writeAndFlush(new TextWebSocketFrame("欢迎使用netty websocket： "+ LocalDateTime.now()));
    }
    
    

}

<html>
<head>
<meta charset="UTF-8">
Netty WebSocket服务器
<head>
<body>
<script type="text/javascript">
var socket;
if(!window.WebSocket){
window.WebSocket = window.MozWebSocket;
}

if(window.WebSocket){
socket = new WebSocket("ws://localhost:8080/websocket");
socket.onmessage = function(event){
    var ta = document.getElementById('responseText');
    ta.value = '';
    ta.value = event.data;
}

socket.onopen = function(event){
    var ta = document.getElementById('responseText');
    ta.value = "打开WebSocket服务器正常";
}

socket.onclose = function(event){
    var ta = document.getElementById('responseText');
    ta.value = "webSocket 关闭";
}



}

function send(){
    if(socket.readyState == WebSocket.OPEN){
    var message = document.getElementById('message').value;
        socket.send(message);
    }else{
        alert("WebSocket 链接未建立成功！！");
    }
}
</script>
<form onsubmit="return false;"> 
    <input id="message" type="text" name = "message" value="Netty最佳实践"/>

<br/><br/>
<input type="button" value="发送" onclick="send()"/>
<hr color="blue"/>
<h3>服务器应答消息</h3>
<textarea id="responseText" style="500px;height:300px;"></textarea>
</form>




</body>


</html>