序言

  • What is Webscoket ?

  • websocket 应用场景

  • 简版群聊实现

  • 代码例子

  • 小结

Webscoket

Websokcet 是一种单个TCP连接上进行全双工通信的协议,通过HTTP/1.1 协议的101状态码进行握手。

http://websocket.org

Websocket 应用场景

Websocket 和 http 协议都是web通讯协议,两者有何区别?先说Http,它是一种请求响应协议,这种模型决定了,只能客户端请求,服务端被动回答。如果我们有服务端主动推送给客户端的需求怎么办?比如一个股票网站,我们会选择主动轮询,也就是”拉模式“。

大家可以思考下主动轮询带来的问题是什么?

主动轮询其实会产生大量无效请求,增加了服务器压力。

由此,websocket 协议的补充,为我们带来了新的解决思路。

简版群聊实现

利用Websocket 实现一个简陋群聊功能,加深一下Websocket 理解。

  1. 假设李雷和韩梅梅都登录在线;
  2. 李雷通过浏览器发送消息转nginx 代理到Ws服务器;
  3. Ws服务器加载所有在线会话广播消息;
  4. 韩梅梅接受到消息。

0_ws

代码例子

后端(shop-server)

引入pom.xml 依赖

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<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-websocket</artifactId>
</dependency>

配置类

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package com.onlythinking.shop.websocket;
import lombok.extern.slf4j.Slf4j;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.socket.server.standard.ServerEndpointExporter;
/**
* <p> The describe </p>
*
* @author Li Xingping
*/
@Slf4j
@Configuration
public class WebSocketConfiguration {
@Bean
public ServerEndpointExporter endpointExporter() {
return new ServerEndpointExporter();
}
}

接受请求端点

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package com.onlythinking.shop.websocket;
import com.alibaba.fastjson.JSON;
import com.google.common.collect.Maps;
import com.onlythinking.shop.websocket.handler.ChatWsHandler;
import com.onlythinking.shop.websocket.handler.KfWsHandler;
import com.onlythinking.shop.websocket.handler.WsHandler;
import com.onlythinking.shop.websocket.store.WsReqPayLoad;
import com.onlythinking.shop.websocket.store.WsRespPayLoad;
import com.onlythinking.shop.websocket.store.WsStore;
import com.onlythinking.shop.websocket.store.WsUser;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.lang3.StringUtils;
import org.springframework.stereotype.Component;
import javax.websocket.*;
import javax.websocket.server.ServerEndpoint;
import java.io.IOException;
import java.util.Map;
/**
* <p> The describe </p>
*
* @author Li Xingping
*/
@Slf4j
@Component
@ServerEndpoint("/ws")
public class WebsocketServerEndpoint {
private static Map<String, WsHandler> wsHandler = Maps.newConcurrentMap();
static {
wsHandler.put("robot", new KfWsHandler());
wsHandler.put("chat", new ChatWsHandler());
}
@OnOpen
public void onOpen(Session session) {
log.info("New ws connection {} ", session.getId());
WsStore.put(session.getId(), WsUser.builder().id(session.getId()).session(session).build());
respMsg(session, WsRespPayLoad.ok().toJson());
}
@OnClose
public void onClose(Session session, CloseReason closeReason) {
WsStore.remove(session.getId());
log.warn("ws closed,reason:{}", closeReason);
}
@OnMessage
public void onMessage(String message, Session session) {
log.info("accept client messages: {}" + message);
WsReqPayLoad payLoad = JSON.parseObject(message, WsReqPayLoad.class);
if (StringUtils.isBlank(payLoad.getType())) {
respMsg(session, WsRespPayLoad.ofError("Type is null.").toJson());
return;
}
WsUser wsUser = WsStore.get(session.getId());
if (null == wsUser || StringUtils.isBlank(wsUser.getUsername())) {
WsStore.put(session.getId(), WsUser.builder()
.id(session.getId())
.username(payLoad.getUsername())
.avatar(payLoad.getAvatar())
.session(session)
.build()
);
}
WsHandler handler = wsHandler.get(payLoad.getType());
if (null != handler) {
WsRespPayLoad resp = handler.onMessage(session, payLoad);
if (null != resp) {
respMsg(session, resp.toJson());
}
} else {
respMsg(session, WsRespPayLoad.ok().toJson());
}
}
@OnError
public void onError(Session session, Throwable e) {
WsStore.remove(session.getId());
log.error("WS Error: ", e);
}
private void respMsg(Session session, String content) {
try {
session.getBasicRemote().sendText(content);
} catch (IOException e) {
log.error("Ws resp msg error {} {}", content, e);
}
}
}

聊天业务处理器

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package com.onlythinking.shop.websocket.handler;
import com.onlythinking.shop.websocket.store.*;
import lombok.extern.slf4j.Slf4j;
import javax.websocket.Session;
import java.util.Date;
import java.util.List;
/**
* <p> The describe </p>
*
* @author Li Xingping
*/
@Slf4j
public class ChatWsHandler implements WsHandler {
@Override
public WsRespPayLoad onMessage(Session session, WsReqPayLoad payLoad) {
// 广播消息
List<WsUser> allSessions = WsStore.getAll();
for (WsUser s : allSessions) {
WsRespPayLoad resp = WsRespPayLoad.builder()
.data(
WsChatResp.builder()
.username(payLoad.getUsername())
.avatar(payLoad.getAvatar())
.msg(payLoad.getData())
.createdTime(new Date())
.self(s.getId().equals(session.getId()))
.build()
)
.build();
log.info("Broadcast message {} {} ", s.getId(), s.getUsername());
s.getSession().getAsyncRemote().sendText(resp.toJson());
}
return null;
}
}

前端(shop-web-mgt)

引入依赖

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npm install vue-native-websocket --save

添加Store

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import Vue from 'vue'
const ws = {
state: {
wsData: {
hasNewMsg: false,
},
socket: {
isConnected: false,
message: '',
reconnectError: false,
}
},
mutations: {
SET_WSDATA(state, data) {
state.wsData.hasNewMsg = data.hasNewMsg
},
RESET_WSDATA(state, data) {
state.wsData.hasNewMsg = false
},
SOCKET_ONOPEN(state, event) {
Vue.prototype.$socket = event.currentTarget;
state.socket.isConnected = true
},
SOCKET_ONCLOSE(state, event) {
state.socket.isConnected = false
},
SOCKET_ONERROR(state, event) {
console.error(state, event)
},
// default handler called for all methods
SOCKET_ONMESSAGE(state, message) {
state.socket.message = message
},
// mutations for reconnect methods
SOCKET_RECONNECT(state, count) {
console.info(state, count)
},
SOCKET_RECONNECT_ERROR(state) {
state.socket.reconnectError = true;
},
},
actions: {
AskRobot({rootGetters}, data) {
return new Promise((resolve, reject) => {
console.log('Ask robot msg', data);
const payLoad = {
type: 'robot',
username: rootGetters.loginName,
data: data
};
Vue.prototype.$socket.sendObj(payLoad)
resolve(1)
})
},
SendChatMsg({rootGetters}, data) {
return new Promise((resolve, reject) => {
console.log('Send chat msg', data);
const payLoad = {
type: 'chat',
username: rootGetters.loginName,
data: data
};
Vue.prototype.$socket.sendObj(payLoad)
resolve(1)
})
},
MessageRead({commit, state}, data) {
commit('RESET_WSDATA', {})
},
}
};
export default ws

编写组件

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<template>
<div>
<ot-drawer
title="聊天"
:visible.sync="chatVisible"
direction="rtl"
:before-close="handleClose">
<div class="chat-body">
<div id="msgList" style="margin-bottom: 200px" class="chat-msg">
<div class="chat-msg-item" v-for="item in msgList">
<div v-if="!item.self">
<div class="msg-header">
<img
:src="baseUrl+'/api/insecure/avatar?code='+item.avatar+'&size=64'"
class="user-avatar"
>
<span class="avatar-name">{{item.username}}</span>&nbsp;&nbsp;
<div style="display: inline-block; float: right">
{{item.createdTime | parseTime('{h}:{i}')}}
</div>
</div>
<div class="msg-body" style="float: left;">
{{item.msg}}
</div>
</div>
<div v-else>
<div class="msg-header clearfix">
<img
:src="baseUrl+'/api/insecure/avatar?code='+item.avatar+'&size=64'"
class="user-avatar"
style="float: right"
>
</div>
<div class="msg-body" style="float: right;background-color: #67C23A">
{{item.msg}}
</div>
</div>
</div>
</div>
</div>
<div class="chat-send">
<el-input
v-model="text"
autocomplete="off"
placeholder="请输入你想说的内容..."
@keyup.enter.native="handleSendMsg"
></el-input>
<div class="chat-btns">
<el-button
class="action-item"
@click="handleClearMsg"
>清空
</el-button>
<el-button
type="success"
class="action-item"
@click="handleSendMsg"
v-scroll-to="{ el: '#msgList', offset: 140 }"
>发送
</el-button>
</div>
</div>
</ot-drawer>
</div>
</template>
<script>
import {mapGetters} from 'vuex'
import store from '@/store'
import {config} from '@/utils/config'
import OtDrawer from '@/components/OtDrawer'
import Cookies from 'js-cookie'
export default {
name: 'UserChat',
components: {OtDrawer},
props: {
visible: {
type: Boolean,
default: false
}
},
data() {
return {
baseUrl: config.baseUrl,
text: '',
msgList: [],
}
},
computed: {
...mapGetters([
'roles', 'isConnected', 'message', 'reconnectError'
]),
chatVisible: {
get() {
return this.visible
},
set(val) {
this.$emit('update:visible', val)
}
}
},
beforeDestroy() {
if (this.isConnected) {
this.$disconnect()
}
},
mounted() {
console.log('Chat mounted.')
if (!this.isConnected) {
this.$connect(config.wsUrl, {
format: 'json',
store: store
})
}
// 监听消息接收
this.$options.sockets.onmessage = (res) => {
const data = JSON.parse(res.data);
console.log('收到消息', data);
if (data.code === 0) {
// 连接建立成功
if (!data.data.msg) {
return;
}
this.msgList.push(data.data)
} else if (data.code === 400) {
this.$message({
type: 'warning',
message: data.data
})
}
};
},
methods: {
handleSendMsg() {
if (!this.text) {
this.$message({
type: 'warning',
message: '请输入内容'
});
return;
}
this.$store.dispatch('SendChatMsg', this.text).then(data => {
this.text = ''
})
},
handleClearMsg() {
this.msgList = [];
Cookies.remove('chatMsg');
// 删除
},
// 聊天关闭前
handleClose() {
// 缓存消息到本地
Cookies.set('chatMsg', JSON.stringify(this.msgList));
this.$emit('update:visible', false)
}
},
created() {
// 加载缓存数据
const chatMsg = Cookies.get('chatMsg');
if (chatMsg) {
this.msgList = JSON.parse(chatMsg);
}
}
}
</script>
<style>
.el-drawer__body {
height: 100%;
box-sizing: border-box;
overflow-y: auto;
background-color: rgba(244, 244, 244, 1);
scroll-snap-type: y proximity;
}
</style>
<style rel="stylesheet/scss" lang="scss" scoped>
.user-avatar {
width: 20px;
height: 20px;
border-radius: 4px;
vertical-align: middle;
}
.msg-header {
font-size: 12px;
color: rgba(109, 114, 120, 1);
}
.avatar-name {
vertical-align: middle;
}
.msg-body {
text-align: center;
max-width: 300px;
min-width: 100px;
word-wrap: break-word;
margin: 4px 0;
padding: 4px;
line-height: 24px;
border-radius: 4px;
background-color: rgba(255, 255, 255, 1);
}
.chat-body {
height: 100%;
position: relative;
}
.chat-msg {
padding: 10px;
.chat-msg-item {
margin-top: 10px;
height: 65px;
}
}
.chat-send {
padding: 20px;
background-color: rgba(255, 255, 255, 1);
position: absolute;
left: 50%;
width: 100%;
transform: translateX(-50%);
bottom: 0px;
}
.chat-btns {
text-align: center;
}
.action-item {
margin-top: 10px;
}
</style>

Nginx 代理配置 nginx.conf (如有需要可添加)

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map $http_upgrade $connection_upgrade {
default upgrade;
'' close;
}
upstream websocket {
server 127.0.0.1:8300;
}
server {
server_name shop-web-mgt.onlythinking.com;
listen 443 ssl;
location / {
proxy_pass http://websocket;
proxy_read_timeout 300s;
proxy_send_timeout 300s;
proxy_set_header Host $host;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_http_version 1.1;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection $connection_upgrade;
}
ssl_certificate /etc/data/shop-web-mgt.onlythinking.com/full.pem;
ssl_certificate_key /etc/data/shop-web-mgt.onlythinking.com/privkey.pem;
}

实现效果图

界面比较丑,因为不太擅长,请大家别见笑!!

1_ws

2_ws

3_ws

项目地址

https://github.com/cuteJ/shop-server (后端)

https://github.com/cuteJ/shop-web-mgt (前端)

项目演示地址

http://shop-web-mgt.onlythinking.com

小结

该篇学习Websocket,以此简单Demo加深印象!