刚学习如何使用netty,这是netty框架中的一个示例,你可以在netty的解压后文件夹路径netty-3.5.9.Final\src\main\java\org\jboss\netty\example\http\websocketx\server下找到所有的java文件
服务器端的websocket实现入口
WebSocketServer.java
package org.jboss.netty.example.http.websocketx.server;
import java.net.InetSocketAddress;
import java.util.concurrent.Executors;
import org.jboss.netty.bootstrap.ServerBootstrap;
import org.jboss.netty.channel.socket.nio.NioServerSocketChannelFactory;
//websocket到服务器端的链接,建议将localhost改为主机ip,各浏览器的支持情况
/**
* A HTTP server which serves Web Socket requests at:
*
* http://localhost:8080/websocket
*
* Open your browser at http://localhost:8080/, then the demo page will be loaded and a Web Socket connection will be
* made automatically.
*
* This server illustrates support for the different web socket specification versions and will work with:
*
* <ul>
* <li>Safari 5+ (draft-ietf-hybi-thewebsocketprotocol-00)
* <li>Chrome 6-13 (draft-ietf-hybi-thewebsocketprotocol-00)
* <li>Chrome 14+ (draft-ietf-hybi-thewebsocketprotocol-10)
* <li>Chrome 16+ (RFC 6455 aka draft-ietf-hybi-thewebsocketprotocol-17)
* <li>Firefox 7+ (draft-ietf-hybi-thewebsocketprotocol-10)
* <li>Firefox 11+ (RFC 6455 aka draft-ietf-hybi-thewebsocketprotocol-17)
* </ul>
*/
public class WebSocketServer {
private final int port;//定义websocket端口
public WebSocketServer(int port) {
this.port = port;
}
public void run() {
// Configure the server.设置Socket channel factory
ServerBootstrap bootstrap = new ServerBootstrap(new NioServerSocketChannelFactory(
Executors.newCachedThreadPool(), Executors.newCachedThreadPool()));
// Set up the event pipeline factory.
// 设置 Socket pipeline factory
bootstrap.setPipelineFactory(new WebSocketServerPipelineFactory());
// Bind and start to accept incoming connections.
// 启动服务,开始监听端口
bootstrap.bind(new InetSocketAddress(port));
// 启动服务时打印提示信息
System.out.println("Web socket server started at port " + port + '.');
System.out.println("Open your browser and navigate to http://localhost:" + port + '/');
}
//main函数
public static void main(String[] args) {
int port;
if (args.length > 0) {
port = Integer.parseInt(args[0]);
} else {
port = 8080;
}
new WebSocketServer(port).run();
}
}
WebSocketServerPipelineFactory.java
package org.jboss.netty.example.http.websocketx.server;
import static org.jboss.netty.channel.Channels.*;
import org.jboss.netty.channel.ChannelPipeline;
import org.jboss.netty.channel.ChannelPipelineFactory;
import org.jboss.netty.handler.codec.http.HttpChunkAggregator;
import org.jboss.netty.handler.codec.http.HttpRequestDecoder;
import org.jboss.netty.handler.codec.http.HttpResponseEncoder;
/**
*/
public class WebSocketServerPipelineFactory implements ChannelPipelineFactory {
public ChannelPipeline getPipeline() throws Exception {
// Create a default pipeline implementation.
//创建默认的管道实现pipeline
ChannelPipeline pipeline = pipeline();
pipeline.addLast("decoder", new HttpRequestDecoder());
pipeline.addLast("aggregator", new HttpChunkAggregator(65536));
pipeline.addLast("encoder", new HttpResponseEncoder());
pipeline.addLast("handler", new WebSocketServerHandler());
return pipeline;
}
}
WebSocketServerHandler.java
package org.jboss.netty.example.http.websocketx.server;
import static org.jboss.netty.handler.codec.http.HttpHeaders.*;
import static org.jboss.netty.handler.codec.http.HttpHeaders.Names.*;
import static org.jboss.netty.handler.codec.http.HttpMethod.*;
import static org.jboss.netty.handler.codec.http.HttpResponseStatus.*;
import static org.jboss.netty.handler.codec.http.HttpVersion.*;
import org.jboss.netty.buffer.ChannelBuffer;
import org.jboss.netty.buffer.ChannelBuffers;
import org.jboss.netty.channel.ChannelFuture;
import org.jboss.netty.channel.ChannelFutureListener;
import org.jboss.netty.channel.ChannelHandlerContext;
import org.jboss.netty.channel.ExceptionEvent;
import org.jboss.netty.channel.MessageEvent;
import org.jboss.netty.channel.SimpleChannelUpstreamHandler;
import org.jboss.netty.handler.codec.http.DefaultHttpResponse;
import org.jboss.netty.handler.codec.http.HttpHeaders;
import org.jboss.netty.handler.codec.http.HttpRequest;
import org.jboss.netty.handler.codec.http.HttpResponse;
import org.jboss.netty.handler.codec.http.websocketx.CloseWebSocketFrame;
import org.jboss.netty.handler.codec.http.websocketx.PingWebSocketFrame;
import org.jboss.netty.handler.codec.http.websocketx.PongWebSocketFrame;
import org.jboss.netty.handler.codec.http.websocketx.TextWebSocketFrame;
import org.jboss.netty.handler.codec.http.websocketx.WebSocketFrame;
import org.jboss.netty.handler.codec.http.websocketx.WebSocketServerHandshaker;
import org.jboss.netty.handler.codec.http.websocketx.WebSocketServerHandshakerFactory;
import org.jboss.netty.logging.InternalLogger;
import org.jboss.netty.logging.InternalLoggerFactory;
import org.jboss.netty.util.CharsetUtil;
/**
* Handles handshakes and messages
*/
public class WebSocketServerHandler extends SimpleChannelUpstreamHandler {
private static final InternalLogger logger = InternalLoggerFactory.getInstance(WebSocketServerHandler.class);
private static final String WEBSOCKET_PATH = "/websocket";
private WebSocketServerHandshaker handshaker;
//接收前台传来的message
@Override
public void messageReceived(ChannelHandlerContext ctx, MessageEvent e) throws Exception {
Object msg = e.getMessage();
if (msg instanceof HttpRequest) { //分辨请求类型并进行相应处理
handleHttpRequest(ctx, (HttpRequest) msg);
} else if (msg instanceof WebSocketFrame) {
handleWebSocketFrame(ctx, (WebSocketFrame) msg);
}
}
private void handleHttpRequest(ChannelHandlerContext ctx, HttpRequest req) throws Exception {
// Allow only GET methods. 只允许GET方法
if (req.getMethod() != GET) {
sendHttpResponse(ctx, req, new DefaultHttpResponse(HTTP_1_1, FORBIDDEN));
return;
}
// Send the demo page and favicon.ico
if (req.getUri().equals("/")) { //设置response
HttpResponse res = new DefaultHttpResponse(HTTP_1_1, OK);
ChannelBuffer content = WebSocketServerIndexPage.getContent(getWebSocketLocation(req));
res.setHeader(CONTENT_TYPE, "text/html; charset=UTF-8");
setContentLength(res, content.readableBytes());
res.setContent(content);
sendHttpResponse(ctx, req, res);
return;
} else if (req.getUri().equals("/favicon.ico")) {
HttpResponse res = new DefaultHttpResponse(HTTP_1_1, NOT_FOUND);
sendHttpResponse(ctx, req, res);
return;
}
// Handshake socket握手
WebSocketServerHandshakerFactory wsFactory = new WebSocketServerHandshakerFactory(
getWebSocketLocation(req), null, false);
handshaker = wsFactory.newHandshaker(req);
if (handshaker == null) {
wsFactory.sendUnsupportedWebSocketVersionResponse(ctx.getChannel());
} else {
handshaker.handshake(ctx.getChannel(), req).addListener(WebSocketServerHandshaker.HANDSHAKE_LISTENER);
}
}
private void handleWebSocketFrame(ChannelHandlerContext ctx, WebSocketFrame frame) {
// Check for closing frame 检查websocket是否关闭
if (frame instanceof CloseWebSocketFrame) {
handshaker.close(ctx.getChannel(), (CloseWebSocketFrame) frame);
return;
} else if (frame instanceof PingWebSocketFrame) {
ctx.getChannel().write(new PongWebSocketFrame(frame.getBinaryData()));
return;
} else if (!(frame instanceof TextWebSocketFrame)) {
throw new UnsupportedOperationException(String.format("%s frame types not supported", frame.getClass()
.getName()));
}
// Send the uppercase string back.
String request = ((TextWebSocketFrame) frame).getText();
if (logger.isDebugEnabled()) {
logger.debug(String.format("Channel %s received %s", ctx.getChannel().getId(), request));
}
ctx.getChannel().write(new TextWebSocketFrame(request.toUpperCase()));
}
private static void sendHttpResponse(ChannelHandlerContext ctx, HttpRequest req, HttpResponse res) {
// Generate an error page if response status code is not OK (200).
if (res.getStatus().getCode() != 200) {
res.setContent(ChannelBuffers.copiedBuffer(res.getStatus().toString(), CharsetUtil.UTF_8));
setContentLength(res, res.getContent().readableBytes());
}
// Send the response and close the connection if necessary.
ChannelFuture f = ctx.getChannel().write(res);
if (!isKeepAlive(req) || res.getStatus().getCode() != 200) {
f.addListener(ChannelFutureListener.CLOSE);
}
}
@Override
public void exceptionCaught(ChannelHandlerContext ctx, ExceptionEvent e) throws Exception {
e.getCause().printStackTrace();
e.getChannel().close();
}
private static String getWebSocketLocation(HttpRequest req) {
return "ws://" + req.getHeader(HttpHeaders.Names.HOST) + WEBSOCKET_PATH;
}
}
前台页面
index.html
<html><head><title>Web Socket Client</title></head>
<body>
<script type="text/javascript">
var socket;
if (!window.WebSocket) {
window.WebSocket = window.MozWebSocket;
}
// Javascript Websocket Client
if (window.WebSocket) {
socket = new WebSocket("ws://localhost:8080/websocket");
socket.onmessage = function(event) {
var ta = document.getElementById('responseText');
ta.value = ta.value + '\n' + event.data
};
socket.onopen = function(event) {
var ta = document.getElementById('responseText');
ta.value = "Web Socket opened!";
};
socket.onclose = function(event) {
var ta = document.getElementById('responseText');
ta.value = ta.value + "Web Socket closed";
};
} else {
alert("Your browser does not support Web Socket.");
}
// Send Websocket data
function send(message) {
if (!window.WebSocket) { return; }
if (socket.readyState == WebSocket.OPEN) {
socket.send(message);
} else {
alert("The socket is not open.");
}
}
</script>
<form onsubmit="return false;">
<h3>Receive :</h3>
<textarea id="responseText" style="width:500px;height:300px;"></textarea>
<br>
<h3>Send :</h3> <input type="text" name="message" value="Hello World!"/><input type="button" value="Send Web Socket Data" onclick="send(this.form.message.value)" />
</form>
</body>
</html>
注意,前台页面建立websocket时socket = new WebSocket("ws://localhost:8080/websocket"); 中的端口必须和服务器端开启服务占用的端口相同new WebSocketServer(port).run();
要import所有的类
主要应用到的netty类的简要说明,具体使用方法请参考API
Bootstrap 一个辅助类的初始化频道。这个类提供了常见的数据结构,它的子类初始化通道和他们的孩子通道使用常用的数据结构。
ServerBootstrap 创建一个新的服务器端的通道和接受传入连接的助手类。
ChannelPipeline ChannelHandlers处理或拦截ChannelEvents频道的列表。 ChannelPipeline实现Intercepting Filter模式,给予用户完全控制事件如何处理,以及如何在管道中的ChannelHandlers互相交流的一种高级形式。
WebSocketServerHandshakerFactory 为服务器提供的适当的握手类
netty官网:https://netty.io/
使用netty框架实现websocket服务器端
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转载自hzfeibao.iteye.com/blog/1724886
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