【websocket】为啥就是握手不成功呢？没看出问题来啊

2014-06-22 10:40:19 1k 阅读 AI 写同款 · GEO 优化AI 选题数据监测一键分发 ›

websocket通信之握手 1. 什么是握手我们知道，所有的 tcp 请求都需要经历三次握手，如下图：握手是websockets中的web，他是http到ws的桥梁为什么是三次，如果是两次会怎么样呢，我们假象一下，客户端：客户端请求连接服务端：服务端回复客户端我已经准备好了这时握手终止，服务端就会想，客户端内小子他有没有准备好啊，心好慌。。。直到客户端回复，大哥我已经准备好了，来吧，开始干大事 ... 阅读详情

tomcat服务器端：
处理websocket连接

package websocket;



import javax.servlet.http.HttpServletRequest;

import org.apache.catalina.websocket.StreamInbound;

import org.apache.catalina.websocket.WebSocketServlet;



public class WebSocketMessageServlet extends WebSocketServlet{



	@Override

	protected StreamInbound createWebSocketInbound(String arg0,

			HttpServletRequest request) {

		// TODO Auto-generated method stub

		String username= (String)request.getSession().getAttribute("user_nickname"); 

		System.out.println(username);

		return new WebSocketMessageInboundPool(username); 

	}  

}

处理websocket请求

package websocket;



import java.io.IOException;

import java.nio.CharBuffer;

import java.nio.ByteBuffer;

import java.util.HashMap;

import java.util.Map;

import org.apache.catalina.websocket.MessageInbound;

import org.apache.catalina.websocket.WsOutbound;



public class WebSocketMessageInboundPool extends MessageInbound{

	

	private final  String user_nickname;

	private static final Map<String,WebSocketMessageInboundPool > Connections = new HashMap<String,WebSocketMessageInboundPool>();

	

	public  WebSocketMessageInboundPool(String username){

		this.user_nickname=username;

	}

	

	protected void onOpen(WsOutbound outbound) {

		// TODO Auto-generated method stub

		addMessageInbound(this);

		super.onOpen(outbound);

	}

	

	protected void onBinaryMessage(ByteBuffer arg0) throws IOException {

		// TODO Auto-generated method stub

		// 向所有已连接的客户端发送文本消息

		try {

			//向特定的用户发送数据

			WebSocketMessageInboundPool  inbound = Connections.get(user_nickname);

			if(inbound != null){

				ByteBuffer bb = ByteBuffer.wrap(arg0.array());

				WsOutbound wb = inbound.getWsOutbound();

				wb.writeBinaryMessage(bb);

				wb.flush();

			}

		}

		catch (IOException e) {

			e.printStackTrace();

		}

	}

	

	protected void onTextMessage(CharBuffer arg0) throws IOException {

		// TODO Auto-generated method stub	

		try {

			//向特定的用户发送数据

			WebSocketMessageInboundPool  inbound = Connections.get(user_nickname);

			if(inbound != null){

			CharBuffer cb = CharBuffer.wrap(arg0);

			WsOutbound wb = inbound.getWsOutbound();

			wb.writeTextMessage(cb);

			wb.flush();

			}

		}

		catch (IOException e) {

				e.printStackTrace();

			}

		}

	

	protected void onClose(int status) {

		// TODO Auto-generated method stub

		removeMessageInbound(this);

		super.onClose(status);

	}

	

	//向连接池中添加连接

	public static void addMessageInbound(WebSocketMessageInboundPool  inbound){

		//添加连接

		Connections.put(inbound.user_nickname, inbound);

	}

	public static void removeMessageInbound(WebSocketMessageInboundPool  inbound){

		//移除连接

		Connections.remove(inbound.user_nickname);

	}

}

xml配置

<?xml version="1.0" encoding="UTF-8"?>

<web-app version="3.0" 

	xmlns="http://java.sun.com/xml/ns/javaee" 

	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 

	xsi:schemaLocation="http://java.sun.com/xml/ns/javaee 

	http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd">

  <display-name></display-name>	

  

  <servlet>

  	<servlet-name>WebSocketMessageServlet</servlet-name>

  	<servlet-class>websocket.WebSocketMessageServlet</servlet-class>

  </servlet>

  <servlet-mapping>

  	<servlet-name>WebSocketMessageServlet</servlet-name>

  	<url-pattern>/web</url-pattern>

  </servlet-mapping>

  

  <welcome-file-list>

    <welcome-file>index.jsp</welcome-file>

  </welcome-file-list>

</web-app>