摘要：
˃˃scanned){//在这里会把含有@ServerEndpoint注解的类扫描加载进来，可以在这里做过滤等操作returnscanned;}}操作类ContentWebSocket.javapackagecom.websocket;importjavax.websocket.*;importjavax.websocket.server.ServerEndpoint;importjava.io.IOException;importjava.util.*;/***@author。*/@ServerEndpointpublicclassContentWebSocket{/***内容集合*/publicstaticMapcontentMap=newHashMap();/***创建*@paramsession*/@OnOpenpublicvoidonOpen{}/***发送消息*@paramcontentId*@throwsIOException*/@OnMessagepublicvoidsendMessage{Listc=contentMap.get;if{c=newArrayList();}c.add;//创建时把当前会话放在集合中，这样集合大小就是实时浏览人数contentMap.put;broadcast;}/***关闭*/@OnClosepublicvoidonClose{Map˂String,List˃requestParameterMap=session.getRequestParameterMap();//关闭时从链接获取content的IDListcontentids=requestParameterMap.get;if(contentids!
有时候我们需要在内容详情页实时浏览人数，这时候我们可以使用websocket实现这个功能
pom.xml
<dependency> <groupId>javax</groupId> <artifactId>javaee-api</artifactId> <version>8.0</version> <scope>provided</scope> </dependency>
或者jar包
tomcat7-websocket.jar
websocket-api.jar
配置类
WebSocketConfig.java
package com.config;
import javax.websocket.Endpoint;
import javax.websocket.server.ServerApplicationConfig;
import javax.websocket.server.ServerEndpointConfig;
import java.util.Set;
public class WebSocketConfig implements ServerApplicationConfig {
@Override
public Set<ServerEndpointConfig> getEndpointConfigs(Set<Class<? extends Endpoint>> endpointClasses) {
return null;
}
@Override
public Set<Class<?>> getAnnotatedEndpointClasses(Set<Class<?>> scanned) {
//在这里会把含有@ServerEndpoint注解的类扫描加载进来 ，可以在这里做过滤等操作
return scanned;
}
}
操作类
ContentWebSocket.java
package com.websocket;
import javax.websocket.*;
import javax.websocket.server.ServerEndpoint;
import java.io.IOException;
import java.util.*;
/**
* @author 。
*/
@ServerEndpoint(value = "/content_websocket")
public class ContentWebSocket {
/**
* 内容集合
*/
public static Map contentMap=new HashMap<>();
/**
* 创建
* @param session
*/
@OnOpen
public void onOpen(Session session) {
}
/**
* 发送消息
* @param contentId
* @throws IOException
*/
@OnMessage
public void sendMessage(Session session,String contentId) {
List c = (List) contentMap.get(contentId);
if (c==null){
c=new ArrayList();
}
c.add(session);
//创建时把当前会话放在集合中，这样集合大小就是实时浏览人数
contentMap.put(contentId,c);
broadcast(c,c.size()+"");
}
/**
* 关闭
*/
@OnClose
public void onClose(Session session) {
Map<String, List<String>> requestParameterMap = session.getRequestParameterMap();
//关闭时从链接获取content的ID
List<String> contentids = requestParameterMap.get("content_id");
if (contentids!=null&&contentids.size()>0){
String contentId=contentids.get(0);
List c = (List) contentMap.get(contentId);
if (c!=null){
//从集合中移除该会话
c.remove(session);
contentMap.put(contentId,c);
broadcast(c,c.size()+"");
}
}
}
/**
* 发生错误
* @param session
* @param error
*/
@OnError
public void onError(Session session, Throwable error) {
System.out.println("发生错误");
error.printStackTrace();
}
/**
* 消息广播
* @param sessions
* @param msg
*/
public void broadcast(List<Session> sessions,String msg){
for (Iterator it=sessions.iterator();it.hasNext();){
Session session= (Session) it.next();
try {
if (session.isOpen()){
//当当前会话没有被关闭 发送消息
session.getBasicRemote().sendText(msg);
}else {
it.remove();
}
} catch (IOException e) {
e.printStackTrace();
it.remove();
}
}
}
}
页面代码
content.html
<span id="viewing">0</span>人正在看
<script>
//观看人数统计
var ws;
var target="ws:localhost:8080/content_websocket?content_id=内容ID";
$(function () {
//处理浏览器兼容性
if ('WebSocket' in window) {
ws = new WebSocket(target);
} else if ('MozWebSocket' in window) {
ws = new MozWebSocket(target);
} else {
alert('WebSocket is not supported by this browser.');
return;
}
ws.onopen = function () {
ws.send('${content.id}')
};
ws.onmessage = function (event) {
$("#viewing").html(event.data);
};
ws.onclose=function (event) {
}
})
</script>