1.什么是webrtc?
WebRTC 是 Web 实时通信(Real-Time Communication)的缩写,它既是 API 也是协议。WebRTC 协议是两个 WebRTC Agent 协商双向安全实时通信的一组规则。开发人员可以通过 WebRTC API 使用 WebRTC 协议。目前 WebRTC API 仅有 JavaScript 版本。 可以用 HTTP 和 Fetch API 之间的关系作为类比。WebRTC 协议就是 HTTP,而 WebRTC API 就是 Fetch API。 除了 JavaScript 语言,WebRTC 协议也可以在其他 API 和语言中使用。你还可以找到 WebRTC 的服务器和特定领域的工具。所有这些实现都使用 WebRTC 协议,以便它们可以彼此交互。 WebRTC 协议由 IETF 工作组在rtcweb中维护。WebRTC API 的 W3C 文档在webrtc。
WebSocket
WebSocket是一种在单个TCP连接上进行全双工通信的协议。WebSocket通信协议于2011年被IETF定为标准RFC 6455,并由RFC7936补充规范。WebSocket API也被W3C定为标准。WebSocket使得客户端和服务器之间的数据交换变得更加简单,允许服务端主动向客户端推送数据。在WebSocket API中,浏览器和服务器只需要完成一次握手,两者之间就直接可以创建持久性的连接,并进行双向数据传输
webrtc架构
2.代码工程
实验目标
实现视频通话功能
pom.xml
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<parent>
<artifactId>springboot-demo</artifactId>
<groupId>com.et</groupId>
<version>1.0-SNAPSHOT</version>
</parent>
<modelVersion>4.0.0</modelVersion>
<artifactId>WebRTC</artifactId>
<properties>
<maven.compiler.source>8</maven.compiler.source>
<maven.compiler.target>8</maven.compiler.target>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-autoconfigure</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-websocket</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-thymeleaf</artifactId>
</dependency>
</dependencies>
</project>
controller
package com.et.webrtc.controller;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.servlet.ModelAndView;
import java.util.HashMap;
import java.util.Map;
@RestController
public class HelloWorldController {
@RequestMapping("/hello")
public Map<String, Object> showHelloWorld(){
Map<String, Object> map = new HashMap<>();
map.put("msg", "HelloWorld");
return map;
}
/**
* WebRTC + WebSocket
*/
@RequestMapping("webrtc/{username}.html")
public ModelAndView socketChartPage(@PathVariable String username) {
ModelAndView modelAndView = new ModelAndView();
modelAndView.setViewName("webrtc.html");
modelAndView.addObject("username",username);
return modelAndView;
}
}
config
package com.et.webrtc.config;
import com.fasterxml.jackson.databind.DeserializationFeature;
import com.fasterxml.jackson.databind.ObjectMapper;
import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Component;
import javax.websocket.*;
import javax.websocket.server.PathParam;
import javax.websocket.server.ServerEndpoint;
import java.text.SimpleDateFormat;
import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
/**
* WebRTC + WebSocket
*/
@Slf4j
@Component
@ServerEndpoint(value = "/webrtc/{username}")
public class WebRtcWSServer {
/**
* 连接集合
*/
private static final Map<String, Session> sessionMap = new ConcurrentHashMap<>();
/**
* 连接建立成功调用的方法
*/
@OnOpen
public void onOpen(Session session, @PathParam("username") String username, @PathParam("publicKey") String publicKey) {
sessionMap.put(username, session);
}
/**
* 连接关闭调用的方法
*/
@OnClose
public void onClose(Session session) {
for (Map.Entry<String, Session> entry : sessionMap.entrySet()) {
if (entry.getValue() == session) {
sessionMap.remove(entry.getKey());
break;
}
}
}
/**
* 发生错误时调用
*/
@OnError
public void onError(Session session, Throwable error) {
error.printStackTrace();
}
/**
* 服务器接收到客户端消息时调用的方法
*/
@OnMessage
public void onMessage(String message, Session session) {
try{
//jackson
ObjectMapper mapper = new ObjectMapper();
mapper.setDateFormat(new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"));
mapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
//JSON字符串转 HashMap
HashMap hashMap = mapper.readValue(message, HashMap.class);
//消息类型
String type = (String) hashMap.get("type");
//to user
String toUser = (String) hashMap.get("toUser");
Session toUserSession = sessionMap.get(toUser);
String fromUser = (String) hashMap.get("fromUser");
//msg
String msg = (String) hashMap.get("msg");
//sdp
String sdp = (String) hashMap.get("sdp");
//ice
Map iceCandidate = (Map) hashMap.get("iceCandidate");
HashMap<String, Object> map = new HashMap<>();
map.put("type",type);
//呼叫的用户不在线
if(toUserSession == null){
toUserSession = session;
map.put("type","call_back");
map.put("fromUser","系统消息");
map.put("msg","Sorry,呼叫的用户不在线!");
send(toUserSession,mapper.writeValueAsString(map));
return;
}
//对方挂断
if ("hangup".equals(type)) {
map.put("fromUser",fromUser);
map.put("msg","对方挂断!");
}
//视频通话请求
if ("call_start".equals(type)) {
map.put("fromUser",fromUser);
map.put("msg","1");
}
//视频通话请求回应
if ("call_back".equals(type)) {
map.put("fromUser",toUser);
map.put("msg",msg);
}
//offer
if ("offer".equals(type)) {
map.put("fromUser",toUser);
map.put("sdp",sdp);
}
//answer
if ("answer".equals(type)) {
map.put("fromUser",toUser);
map.put("sdp",sdp);
}
//ice
if ("_ice".equals(type)) {
map.put("fromUser",toUser);
map.put("iceCandidate",iceCandidate);
}
send(toUserSession,mapper.writeValueAsString(map));
}catch(Exception e){
e.printStackTrace();
}
}
/**
* 封装一个send方法,发送消息到前端
*/
private void send(Session session, String message) {
try {
System.out.println(message);
session.getBasicRemote().sendText(message);
} catch (Exception e) {
e.printStackTrace();
}
}
}
package com.et.webrtc.config;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.socket.config.annotation.EnableWebSocket;
import org.springframework.web.socket.server.standard.ServerEndpointExporter;
@Configuration
@EnableWebSocket
public class WebSocketConfiguration {
@Bean
public ServerEndpointExporter serverEndpointExporter() {
return new ServerEndpointExporter();
}
}
前端页面
<!DOCTYPE>
<!--解决idea thymeleaf 表达式模板报红波浪线-->
<!--suppress ALL -->
<html xmlns:th="http://www.thymeleaf.org">
<head>
<meta charset="UTF-8">
<title>WebRTC + WebSocket</title>
<meta name="viewport" content="width=device-width,initial-scale=1.0,user-scalable=no">
<style>
html,body{
margin: 0;
padding: 0;
}
#main{
position: absolute;
width: 370px;
height: 550px;
}
#localVideo{
position: absolute;
background: #757474;
top: 10px;
right: 10px;
width: 100px;
height: 150px;
z-index: 2;
}
#remoteVideo{
position: absolute;
top: 0px;
left: 0px;
width: 100%;
height: 100%;
background: #222;
}
#buttons{
z-index: 3;
bottom: 20px;
left: 90px;
position: absolute;
}
#toUser{
border: 1px solid #ccc;
padding: 7px 0px;
border-radius: 5px;
padding-left: 5px;
margin-bottom: 5px;
}
#toUser:focus{
border-color: #66afe9;
outline: 0;
-webkit-box-shadow: inset 0 1px 1px rgba(0,0,0,.075),0 0 8px rgba(102,175,233,.6);
box-shadow: inset 0 1px 1px rgba(0,0,0,.075),0 0 8px rgba(102,175,233,.6)
}
#call{
width: 70px;
height: 35px;
background-color: #00BB00;
border: none;
margin-right: 25px;
color: white;
border-radius: 5px;
}
#hangup{
width:70px;
height:35px;
background-color:#FF5151;
border:none;
color:white;
border-radius: 5px;
}
</style>
</head>
<body>
<div id="main">
<video id="remoteVideo" playsinline autoplay></video>
<video id="localVideo" playsinline autoplay muted></video>
<div id="buttons">
<input id="toUser" placeholder="输入在线好友账号"/><br/>
<button id="call">视频通话</button>
<button id="hangup">挂断</button>
</div>
</div>
</body>
<!-- 可引可不引 -->
<!--<script th:src="@{/js/adapter-2021.js}"></script>-->
<script type="text/javascript" th:inline="javascript">
let username = /*[[${username}]]*/'';
let localVideo = document.getElementById('localVideo');
let remoteVideo = document.getElementById('remoteVideo');
let websocket = null;
let peer = null;
WebSocketInit();
ButtonFunInit();
/* WebSocket */
function WebSocketInit(){
//判断当前浏览器是否支持WebSocket
if ('WebSocket' in window) {
websocket = new WebSocket("wss://192.168.0.104/webrtc/"+username);
} else {
alert("当前浏览器不支持WebSocket!");
}
//连接发生错误的回调方法
websocket.onerror = function (e) {
alert("WebSocket连接发生错误!");
};
//连接关闭的回调方法
websocket.onclose = function () {
console.error("WebSocket连接关闭");
};
//连接成功建立的回调方法
websocket.onopen = function () {
console.log("WebSocket连接成功");
};
//接收到消息的回调方法
websocket.onmessage = async function (event) {
let { type, fromUser, msg, sdp, iceCandidate } = JSON.parse(event.data.replace(/\n/g,"\\n").replace(/\r/g,"\\r"));
console.log(type);
if (type === 'hangup') {
console.log(msg);
document.getElementById('hangup').click();
return;
}
if (type === 'call_start') {
let msg = "0"
if(confirm(fromUser + "发起视频通话,确定接听吗")==true){
document.getElementById('toUser').value = fromUser;
WebRTCInit();
msg = "1"
}
websocket.send(JSON.stringify({
type:"call_back",
toUser:fromUser,
fromUser:username,
msg:msg
}));
return;
}
if (type === 'call_back') {
if(msg === "1"){
console.log(document.getElementById('toUser').value + "同意视频通话");
//创建本地视频并发送offer
let stream = await navigator.mediaDevices.getUserMedia({ video: true, audio: true })
localVideo.srcObject = stream;
stream.getTracks().forEach(track => {
peer.addTrack(track, stream);
});
let offer = await peer.createOffer();
await peer.setLocalDescription(offer);
let newOffer = offer.toJSON();
newOffer["fromUser"] = username;
newOffer["toUser"] = document.getElementById('toUser').value;
websocket.send(JSON.stringify(newOffer));
}else if(msg === "0"){
alert(document.getElementById('toUser').value + "拒绝视频通话");
document.getElementById('hangup').click();
}else{
alert(msg);
document.getElementById('hangup').click();
}
return;
}
if (type === 'offer') {
let stream = await navigator.mediaDevices.getUserMedia({ video: true, audio: true });
localVideo.srcObject = stream;
stream.getTracks().forEach(track => {
peer.addTrack(track, stream);
});
await peer.setRemoteDescription(new RTCSessionDescription({ type, sdp }));
let answer = await peer.createAnswer();
let newAnswer = answer.toJSON();
newAnswer["fromUser"] = username;
newAnswer["toUser"] = document.getElementById('toUser').value;
websocket.send(JSON.stringify(newAnswer));
await peer.setLocalDescription(answer);
return;
}
if (type === 'answer') {
peer.setRemoteDescription(new RTCSessionDescription({ type, sdp }));
return;
}
if (type === '_ice') {
peer.addIceCandidate(iceCandidate);
return;
}
}
}
/* WebRTC */
function WebRTCInit(){
peer = new RTCPeerConnection();
//ice
peer.onicecandidate = function (e) {
if (e.candidate) {
websocket.send(JSON.stringify({
type: '_ice',
toUser:document.getElementById('toUser').value,
fromUser:username,
iceCandidate: e.candidate
}));
}
};
//track
peer.ontrack = function (e) {
if (e && e.streams) {
remoteVideo.srcObject = e.streams[0];
}
};
}
/* 按钮事件 */
function ButtonFunInit(){
//视频通话
document.getElementById('call').onclick = function (e){
document.getElementById('toUser').style.visibility = 'hidden';
let toUser = document.getElementById('toUser').value;
if(!toUser){
alert("请先指定好友账号,再发起视频通话!");
return;
}
if(peer == null){
WebRTCInit();
}
websocket.send(JSON.stringify({
type:"call_start",
fromUser:username,
toUser:toUser,
}));
}
//挂断
document.getElementById('hangup').onclick = function (e){
document.getElementById('toUser').style.visibility = 'unset';
if(localVideo.srcObject){
const videoTracks = localVideo.srcObject.getVideoTracks();
videoTracks.forEach(videoTrack => {
videoTrack.stop();
localVideo.srcObject.removeTrack(videoTrack);
});
}
if(remoteVideo.srcObject){
const videoTracks = remoteVideo.srcObject.getVideoTracks();
videoTracks.forEach(videoTrack => {
videoTrack.stop();
remoteVideo.srcObject.removeTrack(videoTrack);
});
//挂断同时,通知对方
websocket.send(JSON.stringify({
type:"hangup",
fromUser:username,
toUser:document.getElementById('toUser').value,
}));
}
if(peer){
peer.ontrack = null;
peer.onremovetrack = null;
peer.onremovestream = null;
peer.onicecandidate = null;
peer.oniceconnectionstatechange = null;
peer.onsignalingstatechange = null;
peer.onicegatheringstatechange = null;
peer.onnegotiationneeded = null;
peer.close();
peer = null;
}
localVideo.srcObject = null;
remoteVideo.srcObject = null;
}
}
</script>
</html>
DemoAppliciation.java
package com.et.webrtc;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
public class DemoApplication {
public static void main(String[] args) {
SpringApplication.run(DemoApplication.class, args);
}
}
以上只是一些关键代码,所有代码请参见下面代码仓库
代码仓库
3.测试
启动Spring Boot应用
测试视频通话
前置条件:必须是https协议,不然无法打开视频和语音权限
输入对方id,进行视屏通话