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创建Server 服务端
添加依赖的包
<dependency>
<groupId>io.netty</groupId>
<artifactId>netty-all</artifactId>
<version>4.1.6.Final</version>
</dependency>
创建一个WebSocketServer类
这里主要绑定一个端口的操作
public class WebSocketServer {
public void run(int port) throws Exception {
EventLoopGroup bossGroup = new NioEventLoopGroup();
EventLoopGroup workerGroup = new NioEventLoopGroup();
try {
ServerBootstrap b = new ServerBootstrap();
b.group(bossGroup, workerGroup).channel(NioServerSocketChannel.class).childHandler(new ChannelInitializer<SocketChannel>() {
@Override
protected void initChannel(SocketChannel ch) throws Exception {
ChannelPipeline pipeline = ch.pipeline();
pipeline.addLast("http-codec", new HttpServerCodec());
pipeline.addLast("aggregator", new HttpObjectAggregator(65536));
ch.pipeline().addLast("http-chunked", new ChunkedWriteHandler());
pipeline.addLast("handler", new WebSocketServerHandler());
}
});
Channel ch = b.bind(port).sync().channel();
System.out.println("Web socket server started at port " + port + '.');
System.out.println("Open your browser and navigate to http://localhost:" + port + '/');
ch.closeFuture().sync();
} finally {
bossGroup.shutdownGracefully();
workerGroup.shutdownGracefully();
}
}
public static void main(String[] args) throws Exception {
int port = 8088;
if (args.length > 0) {
try {
port = Integer.parseInt(args[0]);
} catch (NumberFormatException e) {
e.printStackTrace();
}
}
new WebSocketServer().run(port);
}
}
创建一个WebSocketServerHandler类
这里是主要写自己业务逻辑的地方
public class WebSocketServerHandler extends SimpleChannelInboundHandler<Object> {
private static final Logger logger = Logger.getLogger(WebSocketServerHandler.class.getName());
public static ChannelGroup channels = new DefaultChannelGroup(GlobalEventExecutor.INSTANCE);
private WebSocketServerHandshaker handshaker;
@Override
public void channelRead0(ChannelHandlerContext ctx, Object msg) throws Exception {
// 传统的HTTP接入
if (msg instanceof FullHttpRequest) {
handleHttpRequest(ctx, (FullHttpRequest) msg);
}
// WebSocket接入
else if (msg instanceof WebSocketFrame) {
handleWebSocketFrame(ctx, (WebSocketFrame) msg);
}
}
@Override
public void channelReadComplete(ChannelHandlerContext ctx) throws Exception {
ctx.flush();
}
private void handleHttpRequest(ChannelHandlerContext ctx, FullHttpRequest req) throws Exception {
// 如果HTTP解码失败,返回HHTP异常
if (!req.decoderResult().isSuccess() || (!"websocket".equals(req.headers().get("Upgrade")))) {
sendHttpResponse(ctx, req, new DefaultFullHttpResponse(HTTP_1_1, BAD_REQUEST));
return;
}
// 构造握手响应返回,本机测试
WebSocketServerHandshakerFactory wsFactory = new WebSocketServerHandshakerFactory("ws://localhost:8088/websocket", null, false);
handshaker = wsFactory.newHandshaker(req);
if (handshaker == null) {
WebSocketServerHandshakerFactory.sendUnsupportedVersionResponse(ctx.channel());
} else {
handshaker.handshake(ctx.channel(), req);
}
}
private void handleWebSocketFrame(ChannelHandlerContext ctx, WebSocketFrame frame) {
// 判断是否是关闭链路的指令
if (frame instanceof CloseWebSocketFrame) {
handshaker.close(ctx.channel(), (CloseWebSocketFrame) frame.retain());
return;
}
// 判断是否是Ping消息
if (frame instanceof PingWebSocketFrame) {
ctx.channel().write(new PongWebSocketFrame(frame.content().retain()));
return;
}
// 本例程仅支持文本消息,不支持二进制消息
if (!(frame instanceof TextWebSocketFrame)) {
throw new UnsupportedOperationException(
String.format("%s frame types not supported", frame.getClass().getName()));
}
// 返回应答消息
String request = ((TextWebSocketFrame) frame).text();
if (logger.isLoggable(Level.FINE)) {
logger.fine(String.format("%s received %s", ctx.channel(), request));
}
//currentUserChannel为当前会话通道
Channel currentUserChannel = ctx.channel();
for (Channel channel : channels) {
if (channel != currentUserChannel){
channel.writeAndFlush(new TextWebSocketFrame(channel.remoteAddress()+" "+request));
}else {
channel.writeAndFlush(new TextWebSocketFrame("我"+" "+request ));
}
}
//ctx.channel().write(new TextWebSocketFrame(request + " , 欢迎使用Netty WebSocket服务,现在时刻:" + new java.util.Date().toString()));
}
private static void sendHttpResponse(ChannelHandlerContext ctx, FullHttpRequest req, FullHttpResponse res) {
// 返回应答给客户端
if (res.getStatus().code() != 200) {
ByteBuf buf = Unpooled.copiedBuffer(res.getStatus().toString(), CharsetUtil.UTF_8);
res.content().writeBytes(buf);
buf.release();
HttpUtil.setContentLength(res, res.content().readableBytes());
}
// 如果是非Keep-Alive,关闭连接
ChannelFuture f = ctx.channel().writeAndFlush(res);
if (!HttpUtil.isKeepAlive(req) || res.status().code() != 200) {
f.addListener(ChannelFutureListener.CLOSE);
}
}
@Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
cause.printStackTrace();
ctx.close();
}
@Override
public void channelActive(ChannelHandlerContext ctx) throws Exception { // (5)
channels.add(ctx.channel());
}
@Override
public void channelInactive(ChannelHandlerContext ctx) throws Exception { // (6)
channels.remove(ctx.channel());
}
}
运行WebSocketServer类中的main方法
这时netty服务已经启动了
测试
用websocket连接服务器进行测试
测试的HTML代码如下:
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
Netty WebSocket 时间服务器
</head>
<br>
<body>
<br>
<script type="text/javascript">
var socket;
if (!window.WebSocket) {
window.WebSocket = window.MozWebSocket;
}
if (window.WebSocket) {
socket = new WebSocket("ws://localhost:8088/websocket");
socket.onmessage = function (event) {
var ta = document.getElementById('responseText');
//ta.value = "";
ta.value =ta.value +"\n"+ event.data
};
socket.onopen = function (event) {
var ta = document.getElementById('responseText');
ta.value = "打开WebSocket服务正常,浏览器支持WebSocket!";
};
socket.onclose = function (event) {
var ta = document.getElementById('responseText');
ta.value = "";
ta.value = "WebSocket 关闭!";
};
}
else {
alert("抱歉,您的浏览器不支持WebSocket协议!");
}
function send(message) {
if (!window.WebSocket) {
return;
}
if (socket.readyState == WebSocket.OPEN) {
socket.send(message);
}
else {
alert("WebSocket连接没有建立成功!");
}
}
</script>
<form onsubmit="return false;">
<input type="text" name="message"/>
<br><br>
<input type="button" value="发送WebSocket请求消息" onclick="send(this.form.message.value)"/>
<hr color="blue"/>
<h3>服务端返回的应答消息</h3>
<textarea id="responseText" style="width:500px;height:300px;"></textarea>
</form>
</body>
</html>
运行结果截图:
项目地址:https://gitee.com/jingyang3877/netty-demo
参考博客:
https://www.cnblogs.com/carl10086/p/6188808.html
http://wiki.jikexueyuan.com/project/netty-4-user-guide/implement-websocket-chat-function.html
https://blog.csdn.net/shudaqi2010/article/details/54293000